Thursday, 20 December 2007

Treatment

While I was very optimistic about fenbendazole as a treatment option, I'm a little more worried now. After two days of treatment, I don't see fewer Camallanus worms hanging out of the fish. I am very concerned about whether the fish are ingesting enough of the drug, especially the smallest female Macropodus, which also seems to be the worst infected. I have soaked a mixture of foods in a fenbendazole suspension, and I'm hopeful that they are getting enough of it, but the only way I have of monitoring the treatment is by looking at the worms hanging out of the fish. They still appear red and healthy, which isn't a good sign. This is the final day of the treatment course, so I was hoping for some visible results. "TheGreatBlueDiscus" had visible results after 36 hours, but since he was treating his fish twice a day, that amounts to three treatments.

Since I won't be able to continue the treatment over Christmas, I'm seriously considering euthanising the Macropodus. Not something I would want to do, but I can't afford dead fish floating around the tank for several days (there's only so much my plague of snails can handle).

Timeline of infection

A parasitic nematode like Camallanus needs to get into the aquarium from somewhere. I've been thinking about possible paths of infection. According to Levsen and Berland (2001) Camallanus cotti takes 11 days to fully develop in its copeopd host, and then another 34-42 days to develop after it is ingested by a fish host. Presumably the adult feeds for at least a few days before it extrudes from the anus of the fish and starts releasing larvae of its own. Levsen (2001) found that it took a minimum of 62 days and a maximum of 110 days for visible signs of the parasite in a system with monoxeny - direct (fish to fish) infection. Since I first saw signs on the worms in mid-December, they became infected somewhere between early September and early November. That said, I first noticed the worms last weekend, and once I looked there were worming hanging out of several Macropodus.

In that time period I bought (and didn't adequately quarantine) quite a few fish. The fighter is an unlikely culprit - not only did we buy him too recently, he also shows no signs of infection. The pygmy corys are also unlikely, since they have never been in the main tank. On the other hand, the plant tank has a population of copepods, so I would only have to introduce the copepods, not actually any fish. It's reasonable that Camallanus was introduced with infected copepods that came with the Java moss. The timeline is reasonable - about 55 days. I also transferred a couple larger corys from the plant tank to the main tank, and an Otocinclus. They are also potential sources of infection.

There are, of course, other possibilities. I bought three batches of neon tetras this Fall, and had remarkably high mortality. I also bought some ghost shrimp. The ghost shrimp themselves are unlikely vectors - I have not read about Camallanus infecting shrimp, although there's a slight chance that they were using them as secondary hosts. The neons, on the other hand, are another story.

I bought my first batch of neons back in early September. Four of the five died within two days, and that was followed by a wave of mortality: a fighter, two Angels, two platies and a couple Macropodus. It seems pretty obvious that they weren't the ""cleanest" of fish. The extra burden of Camallanus infection could be blamed for the death of the neons (if you're already feeding parasitic worms, you have fewer resources with which to handle stress), it seems unlikely that transmission of the Camallanus larvae could have resulted in such rapid mortality among the other fish.

While I initially blamed the pet store, the deaths of the other fish led me to wonder whether something had gone wrong with my water, and that the timing might have been coincidental. Anyway, the sole survivor remained in the tank, seemingly healthy, but with a shrunken abdomen (which was always a cause for concern). He died a couple months later, after I bought some more neons to keep him company.

I'm most inclined to blame the neons (or more specifically, the one neon). And while I could do a lot to improve my quarantine procedures, segregating new fish for 2 to 4 months just isn't something I can do at present. While I hate the idea of medicating new fish as a precautionary measure, I can see why people would do it.
  1. Levsen, A. (2001). Transmission Ecology and Larval Behaviour of Camallanus cotti (Nematoda, Camallanidae) Under Aquarium Conditions . Aquarium Sciences and Conservation, 3(4), 315-325. DOI: 10.1023/A:1013137801600
  2. Levsen, A., Berland, B. (2002). The development and morphogenesis of Camallanus cotti Fujita, 1927 (Nematoda: Camallanidae), with notes on its phylogeny and definitive host range. Systematic Parasitology, 53(1), 29-37. DOI: 10.1023/A:1019955917509

Wednesday, 19 December 2007

First casualties?

While the Camallanus still appear well (there are still red worms hanging out of most of the Macropodus), one of the male Macropodus died. Was it worm-related, meds-related or just coincidence? I'm inclined to think it's something other than coincidence. After all, the only visibly infected fish are the Macropodus, so I'm guessing that they are more susceptible to the Camallanus.

It makes me wonder whether there's a stress component. The Macropodus are likely to be the most stressed fish in the tank, since their struggles for dominance consume a lot of their energy. Interesting thought.

Tuesday, 18 December 2007

Camallanus biology

One of the challenges of home diagnoses is "getting it right". Based on the University of Florida IFAS Extension document (Yangong 2006) on nematode infections in fish, a diagnosis of Camallanus infection seems reasonable. But, like any biologist, my first question is: what species? Is there only one species that you tend to find in freshwater aquaria, or are there many?

According to Yanong, Camallanus requires a secondary host, usually a copepod. I suppose a moderately planted tank with driftwood has lots of room for copepods, even if I can't see them. There are enough hiding spots for them in there. So I'm guessing that control of secondary hosts really isn't an option.

"The dreaded Camallanus worm"

On Sunday I noticed something red and spiky protruding from the anus of one of my female Macropodus in the main tank. When I looked at them carefully, I saw something similar on one of the males. While I had never seen anything of the sort before, it was easy enough to recognise based on the descriptions I had read online - my tank was infected with "the dreaded Camallanus worm". A quick Google search reveals two things - one, that aquarists dread this worm (a genus of parasitic nematodes), and two, that there are two fairly well-established treatments: fenbendazole and levamisole. Fenbendazole is a common dog dewormer, and levamisole is apparently used for pigs. Fenbendazole was available at the pet store locally, so I went with that. However, levamisole is probably easier to use, since it can be applied to the water, and is usually effective with a single treatment. Fenbendazole needs to to ingested by the fish, and involves a three-day treatment cycle, followed by another treatment two weeks later. Since the fish have to ingest the drug, the issue of dosage becomes very complicated. On the other hand, the more powerful a drug, the more suspicious of it I am. I was reassured by the low level of warning on the fenbendazole package as well.

Based on what I could find online, I decided to make a solution (or suspension) of the fenbendazole and soak bloodworms in it. For good measure, I also added some sinking pellets to the mix. The fish at both quite happily, so it does not seem like the drug made the food unappealing (either that, or it didn't soak in well enough, which is a concern of mine).

Like everything else in the world of fishkeeping, the major source of information out there is the bulletin boards. And like everything else, I'm hesitant to trust them. I'm glad I came across this University of Florida IFAS Extension document. It was also nice to find this essay at PetFish.net - most people use levamisole, so it's nice to have something against which to compare my own experience.

Tuesday, 11 December 2007

Main tank


Yeah, I know...it barely deserves the designation "planted tank", but that's without carbon dioxide injection or "adequate" lighting.

Sunday, 9 December 2007

Experimenting with Excel

I bought a bottle of Seachem's Flourish Excel - apparently it's basically glutaraldehyde, which serves as a source of bioavailable carbon for aquatic plants (but not algae). It's also supposed to function as an algaecide, especially at higher concentrations, although it isn't actually marketed as such (see Seachem's FAQ; there's also a lot of talk about this on discussion fora).

While I'm terribly curious about the mechanism of action of glutaraldehyde (or whatever it may break down into), I'm mostly curious about whether the plants in my main tank are CO2 limited. My light levels are well below what's recommended, but when people talk about planted tanks, they talk about light and carbon dioxide. Given my current light levels, would my plants be able to utilise additional carbon? I hope to find out.

Not shrimp?

I feel fairly confident that the smaller organisms swimming around my plant tank are not baby shrimp. I'm guessing they're some sort of cladoceran that got introduced either with the plants or the fish or shrimp or, for that matter, on a rock, in some dust... The unusual thing probably isn't getting things like that into your tank, it's a matter of their finding predator-free space. The current inhabitants of the tank (Cherry red shrimp, pygmy corys, Otocinclus) aren't going to both organisms that stay out of their way. Adding a prefilter also makes the tank more friendly to smaller organisms.

Tuesday, 4 December 2007

Betta bulbs

It's been about six weeks since I planted the "Betta bulbs" (Aponogeton sp., allegedly A. ulvaceus), so whatever's going to grow has probably grown. Apparently I planted four in the main tank, one in the Macropodus tank, and two in the plant tank.

They grew well in the plant tank. After about two weeks, one of the bulbs had sprouted, and after another week a flower spike broke the surface of the water. While the first one didn't expand, the plant has produced another four in rapid succession. The young inflorescence looks like the top picture. As it expands it ends up looking more like the lower image.

Shortly thereafter, the second bulb in the plant tank started growing, and it too has produced a succession of flowers. Both plants have also produced floating leaves.

Things were a bit different in the main tank. One of the bulbs floated up fairly soon, apparently dead. A second one eventually made it to the surface, and appears to be dead as well. I'm not entirely sure what happened to the other two - there's one plant that's either a young Aponogeton or a Cryptocoryne sucker, and another leaf that could be a second bulb. In both cases, the plants are small and could easily be something else. I haven't seen any sign of the bulb in the Macropodus tank, but that tank has become so heavily overgrown (since I upgraded from incandescent to compact fluorescent lighting) that I'm really not sure that I would be able to find it if it were growing.

Nineteen

Just counted 19 juvie shrimp (and that doesn't include the little dots that are still flitting around). My best prior count was 15. On the other hand, I haven't seen the last adult for several days - I'm getting a little worried about him.

Using OpenID for comments

I added the option of using OpenIDs to comment on this blog, per phydeaux3's blog post. So it should now be possible to leave comments using AOL/AIM, LiveJournal, TypeKey, WordPress or other OpenID logins.

Phydeaux3 also has instructions on how to alter the settings on to allow this on Blogger.

Saturday, 1 December 2007

Restricted aquatic plants

As I mentioned in the past, I was surprised to realise that one of the most widely recommended aquarium plants was a federally listed noxious weed in the US, and may be illegal to possess in Oklahoma. Today I came across a notice that possession of Cabomba carolinina is illegal in Maine. With a tankful of an unidentified Cabomba sp., I grew a little concerned. But it doesn't fall on the federal noxious weed list, and it doesn't appear to be on the Oklahoma list. Still, there are a few important thoughts in all this:
  • Never release anything from your aquarium into the wild. (That should be pretty obviousl but it isn't).
  • Dispose of all plant material with care. While that is especially true in warmer climates, aquarium plants can obviously even be problematics as far north as Maine.
  • If it grows like a weed, it probably is a weed.

Shrimp skins

After losing three of my four adult shrimp, I was rather concerned when I started finding what looked to be dead juveniles. In the first few cases, I noticed that they seemed rather thin and insubstantial, but after a while I concluded that they were probably shed carapaces, rather than dead shrimp.

That said, some amount of juvie mortality is to be expected. I'm still thrilled with the fact that I ended up with at least a dozen offspring, despite the fact that the tank was very unsuitable for shrimp when they first hatched; the initial setup included a female platy and an unprotected filter intake. On the other hand, the filter box may have provided a refuge/nursery for the young shrimp - since the filter pad was very dirty and the flow was only moderate, it might have been a perfect, food-rich environment for them. Makes me curious how well they tolerate the water flow and whether light is important for their development...

Friday, 30 November 2007

Shrimp

Last week, I lost three of my cherry red shrimp, perhaps as a consequence of a large swing in temperature. I still have one of the original adults (a male, presumably) and at least a dozen juveniles (the largest of which are almost the size of the male).

Over the last few days I have been seeing some tiny organisms swimming around in the tank. Initially they were just at the limits of my perception, but by today they approaching a half a millimetre. Are they some sort of small crustaceans which were introduced with the plants but are finally reaching population sizes that allow them to be noticed, or are the baby shrimp? It's possible that one of the females was carrying eggs that hatched before she died - but I'm surprised that I would have missed something like that. Of course, it's also possible that one of them was carrying eggs when she died - and that some of those eggs managed to survive untended.

I suppose I shall find out eventually whether these are shrimp or something else. Shrimp would be cool. A spontaneous Daphnia population would also be kinda cool.

Aquascaping, part IV

One of the common complaints about aquarium plants is that, as they grow taller, they lose their lower leaves. This is especially true in lower light situations. Most people will recommend trimming the plants, removing the bases and replanting the tops. In a mature, heavily-planted aquarium that's probably the right idea. But when you are trying to grow a stock of plants, it isn't the best idea - in that case, the objective is to maximise your stock of planting material.

When you prune a plant, it will normally produce new shoots from an existing axillary bud. These buds are located at the point where the petiole of a leave joins the stem (or where one used to be before the leaf was shed). When a stem it pruned, one or more axillary bids start to grow. This can produce a bushier plant, but the appearance isn't always what you would want, since you end up with a distinctly smaller shoot coming off of a larger stem.

If the branch develops from the topmost axillary bud, there's a chance that it will develop into a new leading stem. But will that really create the desired look? This is far more important for foreground plants than it is for background plants, of course. From this perspective, it seems like it would make sense to cut plants back are low as possible, leaving an almost indistinguishable old stem. The obvious problem there is the danger of cutting it back too far. The plant can only produce new stem material if it has the resources to do so. How little is enough? That's not only going to vary from species to species, it's also going to vary from individual to individual. A small scrap of Java fern leaf will grow into a new plant, but how little Ludwigia stem (to use the example in these pictures) will produce a new plant?

There is, of course, another problem as well. Large, healthy plants do not appear out of nowhere. If you prune too heavily you may end up with a large stock of skinny, sad-looking plants.

Thursday, 29 November 2007

Aquascaping, part III

Adding rocks created a little more dimension to my tank, but it still wasn't enough. Around the same time I set up the plant tank (or perhaps it would be better to call it a plant nursery, since that is how I originally envisioned it) and purchased a few more plants. Perhaps it was serendipity, but I got some new Cabomba and Water wisteria (Hygrophilia difformis), together with some new Ludwigia. Without high-grade lighting and CO2 injection, I am not going to be able to establish the sort of super-dense garden tanks that are so popular these days. I shouldn't be trying to mimic those setups - I need to work on producing the best aquascape I can, given my constraints. But I can still learn from them without resorting to a crude caricature, a child's imitation.

Although it didn't start well, I have been very happy with Cabomba. Initially it became very stringy, elongating its internodes in a push for the surface of the water. But now, it has thickened up pretty well and filled out. But trimming and replanting the tops, I have the makings of a nice little Cabomba forest. The cut stems have resprouted, and a few uncut stems have also sprouted. While it doesn't seem to match well with modern ideas about aquascaping, it has a "natural" feel to me, the feel of a macrophyte-filled lake. The water wisteria were planted in an area behind the driftwood, adjacent to the smaller of the Echinodorus. The divided leaves emerge from an area dominated by shorter plants with narrow, elongate leaves. I like the effect, but it's a little asymmetrical.

I recently read an article about Dutch aquascaping. While the practice stresses garden-like layout and terraced arrangement isn't something I plan to implement, I was struck by the idea of using "pathways" to create an illusion of depth. I really think that's something I could make use of.

Monday, 26 November 2007

Dietary preferences

It's interesting to see how fish differ in their dietary preferences. I bought some frozen Tubifex worms a few weeks ago, and offered them to my fish. The occupants of the Macropodus tank immediately went crazy over the stuff. On the other hand, in the main tank no one but the Panda corys and the neon tetras showed much interest in it initially. Over time most of the other fish have learned that this is food, but only the pandas would go after it when anything else is present - and the Macropodus still don't realise that Tubifex worms are food. It's odd, given that their siblings are the ones that are most eager to eat it.

I noticed that the leaves of the 'Water wisteria' (Hygrophilia difformis) in the Macropodus tank have been chewed on, so I decided to see how they would respond to blanched spinach. Again, unlike their siblings in the main tank, they went after it enthusiastically. So finally, I offered them blanched zucchini. Twelve hours later it sits untouched at the bottom of the tank. I also added some zucchini to the main tank for the Otocinclus. Much to my surprise, one Macropodus and one cory took a liking to zucchini.

I find it interesting the way that dietary preferences differ both among individuals and within the "culture" of a tank. The Macropodus in the main tank and those in the Macropodus tank are "littermates" and full siblings. And yet they differ in terms of their willingness to take food items. Competition for food is more intense in the Macropodus tank, so it isn't surprising that they would more readily take any food item offered. But why do their siblings in the main tank totally ignore the same food item? The zucchini issue shows another level - that of "personal" food preference.

While I added zucchini primarily for the Otocinclus, the only other fish I have seen eating from it was one of the kuhli loaches.

Saturday, 24 November 2007

Shrimp mortality

I found two of my cherry red shrimp dead today. While I'm sadden by their deaths, I am more concerned by the fact that I don't know what killed them. Was it just chance? I doubt it - one death at random wouldn't surprise me, but two seems to be a bit much of a coincidence. My water parameters seem to be ok. The only real notable change is the weather - temperatures fell from about 27°C/80°F on Monday to about -3°C/27°F on Tuesday night. While I have a heater on the plant tank, it lacks a cover (and the cat pushed the shade away from the window, which probably exposed the tank to draughts).

So is it the weather, water quality, a pathogen, or just coincidence? I wish I knew.

Main tank

Aquascaping, part II

Over the course of the next few months I added a few plants - most notably a couple Spathiphyllum plants - not true aquatics (although I didn't know that when I bought them), but they can survive for extended periods underwater - and a couple more Echinodorus. The Spathiphyllum anchored the back right corner of the tank, while the new Echinodorus plants occupied spaces on either side of the filter intake.

Echinodorus, the "Amazon swords" are an interesting - and diverse - group of plants. My original ones were a tall species - once they get large enough, they produce emergent leaves. They would make nice pond plants and would be good in open tanks, but they really aren't idea for the setup I have unless you are willing to do some major pruning. From what I have read, pruning the roots is probably the most efficient way to produce a smaller plant. The corys excavated the root ball of one of the large Echinodorus, which had the desired effect of dwarfing the plant (for the time being, anyway). I may trim the root mass again in a few months, or try dividing the plant. The other species of Echinodorus is very different - it's really the idea plant for my setup. It has shorter petioles and more lanceolate leaves. Ever since I switched to 6500 K plant bulbs it has produced smaller, denser leaves. It makes a good background plant, filling space at the back of the tank. Since the plants came with plantlets (flower spikes which had either failed to break the surface or, more probably, been submerged when the plants were prepared for shipping), I planted them in what became the Macropodus tank. They seem to have done well in that overgrown, badly overstocked tank. Since I upgraded the lighting in there (from the original incandescent bulbs to compact fluorescent) they seem to be doing better. Unfortunately, conditions in that tank favour algae growth (no snails, excess nitrates) so the leaves tend to have a lot of epiphylls (plants that grow on the leaves of other plants; in this case, algae). During that period I also received a number of plants from a friend. That increased my species diversity, and gave me some new options. I also bought a piece of driftwood. Eschewing the normal rules, I placed it to the from of the tank where it provided cover for my kuhli loaches in a place where they would be visible to me.

Unfortunately, I also suffered an ich outbreak. Since I was unwilling to use any of the commercially available ich treatments (most are based on malachite green, a carcinogen), I decided to go with high temperature + salt. While this succeeded in clearing up the ich problem, it also wreaked havoc on the plants. The entire experience dampened by enthusiasm, and the issue of aquascaping was put on the back burner.

Things changed again late in the summer. As is customary, we went Petosky stone hunting when we were in Michigan, and walking along the pebble beaches I collected a number of other interesting rocks. When I got home I gave some of them a shot in my aquarium. I wasn't sure about their suitability - if they were carbonate based they would probably raise the hardness significantly - but I thought it was worth a shot. I excluded the glittery rocks out of concern that they might contain pyrites (which could yield suphuric acid in the tank) and the Petoskies (pretty, but I knew them to be calcite). I figured I could take them out if they increased the hardness too much.

Adding the rocks changed the tank substantially for the corys. Prior to that, their use of space was largely governed by the availability of cover. Large, open areas to the front of the tank were rarely used during the day. Adding rocks along the bottom of the tank creased more usable space for the bottom-dweller. Coupled with additional substrate in the back left corner of the tank, there was the beginning of an aquascape. Since then I have added a few more plants. Establishment of the plant tank also created a source of cuttings that I could use in the main tank. Unfortunately, the first species I focussed on proved to be a poor choice.

Aquascaping, part I

When I first set up my tank, I was interested in having plants, but I had no real concept of "aquascaping". There was only a limited selection of plants, and I didn't have any idea of how densely I should plant the tank. In a certain sense I was lucky - I didn't waste money planting a dense garden which would have promptly died through lack of light and carbon dioxide.

My initial setup was deficient in more ways than I really want to discuss. The Echinodorus plants were a good focal point on one end of the tank. Since they were sold singly it was pretty easy to plant them properly. The Java ferns were, similarly, easy enough to separate, although I didn't know that you were supposed to keep the rhizome above the substrate. Even more problematically, I had no idea that I should separate the bunched plants. Had I separated the Ludwigia, Bacopa and Myriophylum I would have had a more garden-like arrangement, and may well have had better survival rates. Other problems included the total lack of non-plant features on the bottom of the tank and no real sense of what my ultimate design goal.

With no goal it was easy to end up headed nowhere.

Friday, 23 November 2007

The cave

This is one of my favourite features of my aquascape. It's a bit less impressive viewed at the level of the tank, but I still like the look.

It's probably pretty apparent that the Cabomba could use a bit more light. The microsword (Lilaeopsis brasiliensis) in the foreground was uprooted by the fish (probably the kuhli loaches) and I replaced it with some small Hygrophila polysperma (which I removed when I decided to eliminated the species from my tanks).

Wednesday, 21 November 2007

Shrimp

I counted at least a dozen baby cherry red shrimp yesterday. The largest of them is 11-12 mm long (plus tail).

And in the main tank, I have seen a ghost shrimp twice in the last couple days. That was quite a surprise - I didn't really think any had survived the initial introduction.

Tuesday, 20 November 2007

Photoperiod and plant growth

As I mentioned in my last post, conventional wisdom is that aquarium plants "can't use" light beyond a 10-14 hour photoperiod, and anything beyond that ends up going into algal growth. Explanations like that don't make sense to me...is photosynthesis supposed to shut down at a certain point? But that doesn't mean that the observation isn't true (something this well established is likely to be based on fact), but I'm curious about the underlying mechanism.

In a 1998 paper, E.B. Jensen and B. Veierskov looked at the effect of photoperiod on photosynthesis in tomatoes. They found that increasing the length of the photoperiod from 8 hours to 16 hours caused the carbon dioxide assimilation rate (i.e., the rate of photosynthesis), but photosynthetic rates fell with a 23.5-hour photoperiod. (Open bars in the figures). Starch and sugar concentrations showed a similar pattern.

This is interesting - an increase (and then decrease) in the rate of photosynthesis. The paper provides a mechanism for this difference - changes in chlorophyll a, chlorophyll b and carotenoid levels probably explain these differences.

Protein levels increased sharply at a 23.5-hour photoperiod, as did ethylene production (ethylene is a plant hormone which is produced in response to stress). The transgenic pTOM13 plants (shaded bars) have a reduced ability to produce ethylene. Jensen and Veierskov concluded that ethylene production is likely to be the cause of the "chlorosis, leaf distortion, purpling of older leaves and growth reduction".

So what does this mean with regards to the original question of how long to leave the lights on in your aquarium? It's a start - the idea that overly long photoperiod can damage plants is reasonable. But you can't readily translate that into the specific requirements of even the most common aquarium plants. More importantly, saying that excessive day length harms plants isn't the same as saying that it encourages algal growth. While plant growth appears to suppress algal growth (or so says another piece of conventional wisdom), at this point it seems more likely that algal growth would either be an indirect effect (maybe increased nutrient availability driven by decreased plant growth?) or a direct effect unrelated to plant growth (for example, algal growth may increase continuously with photoperiod, while plant growth falls off once it exceeds some threshold, creating a relative advantage for algae).

I need to keep looking.
  1. Jensen, E.B. and B. Veierskov. 1998. Interaction between photoperiod, photosynthesis and ethylene formation in tomato plants (Lycopersicon esculentum cv. Ailsa Craig and ACC-oxidase antisense pTOM13. Physiologia Plantarum 103:363-368.

Monday, 19 November 2007

Photoperiod

One of the bits of conventional wisdom that floats around aquarium articles and message boards is that tropical plants, which are adapted to a 10-14-hour photoperiod, and that anything beyond that is a bad idea. This article is a typical example:
Leaving the lights on 24 hours a day while you were away was not a good idea. Most of the plants we use in the aquarium come from tropical areas, and are adapted to about 10 and 14 hours each of day and night. At 2 to 3 watts per gallon of fluorescent light, a 12-hour photoperiod works well for me. This can be adjusted based on lighting intensity. In no case does it make sense to extend the photoperiod much beyond 14 hours. Most higher plants will stop photosynthesizing at this point, while the algae will take full advantage of this situation.
But is this really the case? Does photosynthesis shut down after 12 hours? Possible, but what's the source? I need to figure this out.

Equipment maintenance

Over time, I noticed that the water flow on my filters declined. In the case of the Macropodus tank, I wasn't too concerned - quite frankly, it's easier to ignore that tank than it is to stress about the fact that there are 40 fish I don't want (but don't know how to get rid up) taking up one of my tanks. Then I noticed that the biowheels on my main tank wouldn't turn. I cleaned the filters, I cleaned the intake, but nothing seemed to work. If anything, things got worse. Finally, I noticed the water flow decline on the plant tank. That started to bother me - the filter was only a few months old. Was the motor burning out already?

Finally, I decided to take it apart and clean it properly. Only when I took it apart, and then looked at the set-up and maintenance instructions, did I realise what the problem was. It was amazingly easy to do. The next day I did the same for the other tanks, and I was amazed at the water flow in the main tank. I had totally forgotten what it was like.

Of course, a few seconds on google could have told me that I needed to do that. Oh well...

On breeding corys

My fascination with corys dates to my childhood. I bought my first corys when I was 11 or 12. I had no idea what they were, but eventually I was able to match them to illustrations of Corydoras aeneus which, as it turns out, is native to Trinidad. After we moved the corys ended up as the sole denizens of their tank, alone and ignored. So it was much to my surprise that I found four or five of them swimming around in a tank where there had only been three. (And I use the word "tank" loosely - it was a very large old enameled pot that had once been used to boil diapers.)

Ever since, I have had a fascination with corys. They were among the first fish that I bought when I got back into fish keeping this year, and I now have five species of Corydoras. While I would be happy just collecting them, I have an urge to replicate what I once achieved through chance and neglect.

Most descriptions of corys mention spawning - this species is easy to spawn, that one is very difficult. In addition, they refer to the "classic" T configuration. Some people will even mention that the male forms the top of the T, and the female faces him. But I was never able to visualise it, and no one bothered to provide illustrations. Thankfully, I have finally come across an article with pictures. Ian Fuller's article So you want to breed corys? provides just that - a picture of the "classic T-position" (scroll down pretty much to the bottom of the page). On seeing that, my reaction was "oh, really?" Have I seen that before? I may have. It has a terribly commonplace look, the sort of thing I would not have identified as spawning behaviour. A while ago my first corys (species unknown) did a lot of what looked like spawning behaviour. I was looking for the T position, but never saw it (I was looking for something more dramatic). In my main tank eggs would probably be snail food and fry fish food. But it makes me hopeful that I could induce them to try a second time.

More pygmy corys

Having stripped about half the biomass out of my plant tank, I became reacquainted with the pygmy corys. I started out with ten in the tank; I'm not certain how many of them survived, but I'd say there's a minimum of nine. When they were first forced out into the open they became very skittish, but they seems to be settling down a little. So the thought of getting them to breed crossed my mind. Unlike Macropodus, I suspect there's a market for these fish - I have only seen them once at local pet stores. While I may not be able to sell them, I suspect I could get the one independent store to trade some.

I googled breeding pygmy corys and got several promising hits. While they all agreed that the fish weren't difficult to breed, they differed markedly with respect to their thoughts on the idea setup. Ian Fuller at Pets Parade ("Britain's Biggest Petshop") says he uses four males and two females for breeding. However, he is writing about all five "pygmy" species in the article (Corydoras cochui, C. gracilis, C. habrosus, C. hastatus, C. pygmaeus and C. xinguensis), so that may not be the place to look for something overly specific.

Writing at AquariumFish.com, Mike Hellweg gives a very detailed description of C. pygmaeus breeding behaviour. He notes that, although they spawn in a group, each male "stakes out" a specific female and breeds only with her. Consequently, he goes for balanced sex ratios in his breeding tanks. On the other extreme, Kaycy Ruffer at PlanetCatfish recommends "at least one female to six males".

There's a wealth of fish keeping advice online, but the problem is that people simply say what works for them. All three of these appear to have successfully spawned pygmy corys. None of them given any indication that they have experiments with different setups, and only Mike Hellweg explains why he made the decisions he made. It's like reading testimonials for "alternative medicine". Sure, people took the product and got result x, y or z. But how do you separate coincidence from successful practice? Therein lies the problem.

Irresponsible plant dealers

Almost every fish store I have been to sells non-aquatic plants as aquarium plants. In some cases the plants are non-aquatic, but can persist under water for months. If purchasers were warned, I could see a case being made for some plants (like Spathiphyllum, which is apparently good with very boisterous fish). It's irresponsible to see plants like that to unsuspecting aquarists. I was quite disheartened by my initial attempts at establishing plants (although salting the tank to deal with ich was probably the biggest plant killer).

It's one thing to sell your customers something that will never work. It's quite another to actually make them accomplices in lawbreaking. While I have not seen Hygrophila polysperma for sale in a fish store, it's available online. There are also reports that it is sold in pet stores. More disturbing is that fact that aquarium plant books published by reputable publishers say nothing of the fact that transporting the plant requires a permit, and possession in some states is a crime. Granted, there's no reason for a British publication to say anything about this unless they are producing an edition for the US market.

Saturday, 17 November 2007

Destroying the plant tank

I recently discovered the Hygrophila polysperma is listed as a federal noxious weed, making it illegal to transport without a license. It didn't occur to me to check state laws. Turns out, it appears to be illegal to possess the plant in Oklahoma. So, sadly, I decided to get rid of it.

In three of my tanks that isn't a huge deal - while it was in all of my tanks, it wasn't a major component of the flora. In the plant tank, on the other hand, it was clearly the dominant plant. When I established the tank I took a lot of small bits and planted them with the hope of getting good stems to establish elsewhere. So not only was there a lot of biomass, there were an awful lot of stems of the stuff. Removing them is not only traumatic to me, it's also hard on the fish. After living life well-hidden, they are not out in the open. And I have to start over on my planting ideas.

The other challenge, of course, is disposing of the stuff. Two options are not available - sending it down the drain or throwing it in the garbage. Luckily, it has never flowered, so I don't have the worry of killing seeds. Still, just to be on the safe side, I decided to microwave the plant material for five minutes, and then let it dry completely.I can't see how it would survive that. Now the next challenge - getting the "plant tank" back to the point where it deserves that name.

Update: The challenge, I think, isn't killing the plant, it's finding all the bits. The very characteristics that make Hygrophila polysperma a problem plant also make it hard to eradicate - it can sprout from small pieces of stems floating somewhere in the aquarium (or body of water).

Thursday, 15 November 2007

Betta Bulb update

As I mentioned previously I planted several "Betta Bulbs" in my tanks a few weeks ago. While I haven't seen any signs of life in either my main tank or the Macropodus tank, I noticed something new in my plant tank about a week ago. Today I noticed a flower spike that had broken the surface of the water, and this evening I noticed a second plant.

One of my first thoughts was that while the plant could easily be an Aponogeton, I had my doubts as to whether it was Aponogeton ulvaceus (as the packaging claimed) - which is probably a good thing. Aponogeton ulvaceus tends to be a very large plant with broad, wavy leaves that presumably resemble the alga Ulva. One online description says the leaves are 3-10 cm broad. These plants appear to have far narrower leaves - at most a centimetre broad - but that might change as the plants get bigger. Perhaps the flowers will give me a better sense of what species I actually have, although there is mention of widespread hybrid origin of cultivated plants.

Sunday, 11 November 2007

Hygrophila polysperma - a noxious weed

In writing the previous post, I realised that Hygrophila polysperma is on the Federal Noxious Weed List.

According to the Federal Noxious Weed Regulations:
(a) No person may move a Federal noxious weed into or through the United States, or interstate, unless:
(1) He or she obtains a permit for such movement in accordance with paragraphs (b) through (e) of this section; and
(2) The movement is consistent with the specific conditions contained in the permit.
(b) The Deputy Administrator will issue a written permit for the movement of a noxious weed into or through the United States, or interstate, if application is made for such movement and if the Deputy Administrator determines that such movement, under conditions specified in the permit, would not involve a danger of dissemination of the noxious weed in the United States, or interstate; otherwise such a permit will not be issued.
(c) All such permits issued shall contain in written form in the permit any conditions (other than those conditions specified in this part) under which the permit is to be granted, e.g. conditions with respect to shipment, storage, and destruction.
(d) If the permit is denied, the applicant shall be furnished the reasons therefor.
(e) The Deputy Administrator may revoke any outstanding permit issued under this section, and may deny future permit applications, if the Deputy Administrator determines that the issuee has failed to comply with any provision of the Act or this section, including conditions of any permit issued. Upon request, any permit holder will be afforded an opportunity for a hearing with respect to the merits or validity of any such revocation involving his or her permit.
While the realisation that I may well be harbouring a "noxious weed" was a bit of a shock, the real issue appears to be one of transporting the plant, and potentially releasing it into the wild. According to the University of Florida Center for Aquatic and Invasive Plants, H. polysperma is present in parts of southern Texas and most of Florida, and has been reported from Virginia.

It's really a shame. The fact sheet describes almost the perfect plant for most aquarists:
Stems brittle, easily fragmenting, easily developing new stands from rooted nodes of even small fragments (Les and Wunderlin 1981). Able to form dense monocultural stands with emersed stem tips from depths as great as 3 m (10 ft) or more (Hall and Vandiver 1990). Able to photosynthesize in lower light than most native submersed species (Spencer and Bowes 1984). Tends to grow more vigorously in flowing water (Van Dijk et al. 1986). Flowers in fall and winter, with a high percentage of seed set in Florida populations (Les and Wunderlin 1981).
It makes sense though. A plant that does everything an aquarist could hope for will, necessarily be a weedy species with pest potential. I need to make sure all plant bits I dispose of are dead. I generally do that anyway, not because I am conscientious but rather, because I tend to leave trimmings sit in a container for a few days before I dispose of them. In that time they dry out thoroughly. Now though, I need to make a bad habit into a rule.

Update: According to this discussion, possession in Oklahoma may be a crime. Sadly, I think it's time to get rid of all of it. Now to figure out how to do that safely.

Saturday, 10 November 2007

Tank #4

I decided to bring the 2-gallon hexagonal acrylic tank back into use. Although we thought about shrimp or African Dwarf Frogs (Hymenochirus curtipes), we ended up going with a fighter again.

The tank has an undergravel filter and a fairly coarse gravel base, so it really isn't a good candidate for a planted tank. Nonetheless, I decided to set it up that way. That allowed me to use my plant tank for the purpose I set it up in the first place - as a source of plant material for my other tanks. I took a small Echinodorus out of the Macropodus tank, but the rest of it came from the plant tank. I took a good bit of Ceratophyllum (Hornwort), though most of it ended up in the Macropodus tank, opening up a large space in the plant tank. I also cut back the large stem of Cabomba that have reached the water level and grown across much of the tank. I pulled out a rooted Ludwigia plant and took a couple cuttings of Hygrophila difformis (Water Wisteria) and Hygrophila polysperma, which is considered one of the easiest aquarium plants (and not surprisingly, apparently it's a noxious weed).

I'm hoping the plants will do well in the new tank. I'm more interested in how that trimming will affect the plants that remain in the plant tank.

Thursday, 8 November 2007

Baby shrimp

I saw at least one baby cherry red shrimp in the plant tank yesterday. It was pretty cool - about 3 mm long. It isn't ideal breeding habitat for them though - between the filter and the pygmy corys, I don't think the survival probabilities are too high. The tank is good overall - it's densely enough planted by now there would be adequate hiding spaced from anything but pygmy corys.

I'll see what the survival rates are like. Hopefully I have at least one male among the shrimp, and they'll breed again soon. It takes about 28 days, apparently, after the eggs are laid. We'll see what happens next.

Some thoughts on tank evolution

Posting the "before and after" pictures of my tank got me thinking about the importance of a few key elements. The biggests problem with the "before" shots isn't the lack of plant cover, it's the fairly uniform and boring layout of the sediment. If I were to do it again, I probably wouldn't go for black and white gravel, but I would definitely start things up with a lot more rocks and wood.

If you have one big open space, fish use the tank as one big open space. Adding plants in the back and sides can create smaller refuges, hiding spots, but that doesn't offer any additional options with respect to swimming. The fish can hide or the fish can swim. But that's about all. When I added the driftwood in the centre of the tank I created an up-front hiding space (without it I would probably never see the kuhli loaches), but it still doesn't change swimming options. A shy fish can dash from cover at the edge to cover at the centre, but it's still a dash. But scattering rocks across the bottom of the tank (and adding plants between the rocks) changed the usable space dramatically. Suddenly the bottom of the tank was usable to relatively shy fish. It certainly made some of the corys more active during the day. This fairly small change led to created a new microhabitat encompassing most of the bottom of the tank. It should have been obvious, but it wasn't.

Monday, 29 October 2007

Substrate in a planted tank

When I set up my tank, I was at least as interested in having plants as I was in having fish. To that end I bought a bag of nutrient-rich substrate, which is covered with a layer of pea gravel. Therein, I suppose, I made my first big mistake. While the gravel made an attractive bed for the aquarium, it isn't the best thing to grow plants in. So while you see pictures of planted tanks in which the plants spread rapidly, the coarse gravel which covers the bottom of my tank is likely to be a serious hindrance to the development of the sort of "carpet" of vegetation I would really like. Of course, there are other hindrances - lighting and carbon dioxide. While I have improved the lighting in all of my tanks, I'm sure carbon dioxide levels are still inadequate. While passive CO2 systems are easy enough to build, you really need to monitor pH if you add CO2. After all, excess amounts of CO2 could harm the fish.

In a sense I am still early in what I might consider the third stage of tank evolution. In the first stage I planted the plants I bought, and watched the fish dig them up. Then, when I salted the tank to handle my ich outbreak, I lost a lot of plants. I also kinda gave up on the whole idea. More recently, especially since I established the plant tank, I have given optimism a new shot. With the plants I established in August and September growing, and with some new plants from Houston, there's enough stuff in there to start thinking some more about aquascaping. Removing the mass of floating plants (mostly uprooted stuff) has changed the light distribution in the tank.With most light penetrating to the depths of the tank, I am hopeful that my plan to create a shorter "meadow" to the from of the tank might work. At least somewhat.
Here are a couple shots of the tank when it was first set up. The left side of the tank is still remarkably similar - the area is still dominated by the two Echinodorus plants that I put in first. While some of the Java fern (visible below the intake for the filter) are still around, I don't think anything else survives except for a tiny piece of Bacopa.
Here's the tank today:










While it's nowhere near a perfect planted tank, I think it has matured nicely.

Saturday, 27 October 2007

Betta Plant Bulbs

A few weeks ago I picked up a package of dried bulbs labelled "Betta Plant Bulbs" (Aponogeton ulvaceus). And then I put it aside and did nothing.

I finally got around to looking up what the species was like. On PlantGeek the species is described as:
A very striking plant with huge fluted and sometimes corkscrew leaves. This plant does best in a large aquarium where it will take over a large portion of the tank. It may or may not require a dormant period.
They also describe it as requiring "medium high" light, which probably means my tanks will be on the low end.

The package contained seven bulbs. I put four in my main tank, two in the plant tank and one in the Macropodus tank. While the package says "guaranteed to grow in 30 days" (or they will replace the bulb(s) that fail to grow), replacement requires that you (a) retain "proof of purchase" (did I keep the receipt?) and (b) that you return the bulb. Which would mean digging through the substrate and finding it. Since each bulb is worth about 50 cents, between postage and the disturbance to the tank, it's pretty safe to say that I won't be seeking a refund (which makes me a bad consumer).

Hopefully there'll be something to report within the next 30 days.

Thursday, 25 October 2007

Macropodus social organisation

Macropodus (Paradise fish) are supposed to be aggressive and territorial, unlikely to tolerate others of their species. Siblings are sometimes described as being more tolerant. Having started off with a pair and gradually added several of their offspring into the tank, I seemed to have the perfect Macropodus society. Aggression was minimal, and I saw no evidence of the sort of behaviour I had read about. I gave away the first batch of progeny, and had the same experience when I added some more juveniles from the breeding tank.

My second purge was more extensive, and I ended up giving away all the large Macropodus. So when I added a new batch from the breeding tank, the effect was very different. They have remained much more aggressive with one-another, displaying at (and chasing) their siblings. No clear dominance hierarchy seems to have emerged either. Since it makes for far prettier fish, and since I haven't seen any evidence of fin damage or wounding, I am not too worried - just interested in how social dynamics seem to emerge.

Wednesday, 24 October 2007

Breeding Angelfish?

Two of my four angels died in the aftermath of my neon tetra fiasco. Since I lost one member of each "pair" of angels, I figured that my chances of breeding them was pretty close to nil. However, the two surviving angels are now behaving like they intend to breed.

Over the last week or so, the angels became very aggressive with one-another. That was nothing new - when there were four fish, they fought over the tank. One pair claimed the central half of the tank, and forced the other pair to occupy the ends of the tank. But this behaviour was different - one fish would attack, but the other would stand its ground, but not fight back. More tellingly, they have taken to cleaning Echinodorus leaves. After reading Bill Dawes FAQ on breeding angels, it seems pretty likely that they are attempting to spawn.

Monday, 22 October 2007

Cherry shrimp

I have been intrigued by shrimp for a long time. Petsmart always has lots of ghost shrimp, but Lindsay has never liked transparent organisms, so I was really glad to come across Cherry shrimp in Houston. They weren't cheap, but they are supposed to breed readily. I'm hopeful - I love shrimp in aquaria.

Managing algae

The plant tank has always had an algae problem. Initially it was overrun by cyanobacteria (blue-green algae), and then it had an infestation of a brownish-looking alga. Adding some corys helped, since they disturbed the bottom and broke up the near-continuous mat. When I finally added filtration things improved a lot. Recently, however, algal populations started to climb again, and I had a small bloom of cyanobacteria. While I was gone over the weekend, I decided to switch off the light and just give the tank a little natural light that comes through the window. The effect was remarkable - after just 2.5 days of low light, the algal had thinned significantly. The plants look fine, the algae does not.

Pygmy corys

We took a trip to Houston this weekend, and I visited the most amazing fish store I have ever seen. Granted, that isn't all that difficult (given the selection where I am). The selection of fish and plants was amazing.

If I had that money (and tank space) I could have brought home dozens of cool fish. One of hte most remarkable fish I came across was Polypterus, a somewhat ugly, but truly fascinating-looking fish. But I really fell in love with the Pygmy corys. A little over a centrimetre long, they are very cory-like in their bahaviour, schooling around the tank, foraging along the bottom. The great thing about them is their size - I bought 10 of them, put them in my plant tank (which is only a 10-gallon tank) and I have a school of corys. I'd like to put them in the main tank eventually, but I am a little concerned that the angels might see them as food. The only problem with them is that they are similarly patterned to Otocinclus, and they don't seem to be good at telling the difference. The result in that they try to school with the Otocinclus. Since Otocinclus is a sucker-mouthed catfish, they prefer to hang onto the glass, not be harassed by smaller fish. (It's pretty remarkable to find yourself thinking of Otocinclus as "the bigger fish").

Friday, 14 September 2007

Hunting

I think it's pretty safe to say that the best hunters I have had are Angels. They are probably the most intelligent fish I have had, and seem able to plan their moves beyond the most immediate. Fighters, on the other hand, don't strike me as very good hunters.

I had a male fighter in a tank with 30-40 Macropodus fry for about a week (see here). Remarkably, when I finally took him out of the tank, there were still several fry left. It may have been that he was in breeding mode, and was less prone to eat little creatures swimming around his nest (although I saw him eat some of them right under his nest), but having watched him hunt, I think he was just an inefficient hunter (the female fighter, who was in the tank with him for certain periods of time, seemed to be better at it, thought still not an expert).

As I could tell (based on my rather limited observations) fighters hunt by swimming up to a potential prey item, and then snapping at it. If they prey item (Macropodus fry, in this case) can see them, they can get away. The fighter won't give chase, so it's possible to escape. Angels, on the other hand, seem to give chase and corner their prey - when the angels went after the neons, they gave chase and cornered their prey. Of course, they went at the fish as a group, which is something a more solitary fish like a fighter is unable ot do. But still, even single angels strike me as more efficient hunters. I suppose it reflects their prey source. Fighters aren't good at swimming fast - their long fins aside (something their ancestors wouldn't have had), they just aren't the sort of sustained swimmers that angelfish are. They probably depend more on prey that is either unable to see them (mosquito larvae?) or on lying in wait. Angels, on the other hand, are better swimmers. Given their reaction to the neons, I'm pretty sure that they are piscivores in nature.

Thursday, 13 September 2007

The plant tank

About a week ago I moved the breeding pair of Macropodus out of the plant tank into the main tank. Above all else, I wanted them to just stop breeding, but I also was afraid that they were harassing the Otocinclus too much. But then, last weekend, on a whim we bought a couple of fighters. The male was the kind of colourless/golden fish you see from time to time these days, while the female was either the same of what we used to call "pearl". I figured the plant tank would make a good quarantine tank for them, although I was rather unhappy with the fact that this would mean that the Macropodus fry would become fish food. (Remarkably, several of them survived a week with the fighters).

Once I got them home I realised how small the female was. Still, given the size of the Macropodus female which had just bred in that tank, I wasn't going to rule out the possibility that she was ready to breed. Since the male built such an extensive nest, I let her out, but she was obviously uninterested. After a few hours I separated them again. Although I tried several times, I was unsuccessful. After a week of isolation I put them into the main tank. Maybe once she gets bigger I will give it another shot.

One big problem in the plant tank has been algal growth - a brownish, filamentous alga has gradually overgrown everything. Although I have removed a lot of it, the tank is still overrun with it. The two Otocinclus are either uninterested in this type of algae, or are simply overwhelmed, so I decided to buy a few more (I had wanted more than two when I bought these, but they only had two). And, since I've always wanted more corys, I bought a few of them as well - a new species, bringing my cory diversity to 4 species. I figured that since they root around on the bottom a lot more, they are likely to increase habitat heterogeneity. I'm hoping that this will have some effect on the algal overgrowth.

Friday, 7 September 2007

Life and death

...luckily, without life in death.

Only one of the neons survived the weekend, which is really sad. It may have been a water-quality thing, I'm really not sure. Yesterday was truly tragic - my fighter, an angel and one of the platies all died. I was worried about the angel - it had a large gash on its side on Thursday morning. I was saddened, but not shocked, that it had died. But I'm not sure what killed the other fish. I did a major water change, but I'm not sure what else I could have done. But to little avail - now a second one of my angels is dead. It's really sad - they had grown into such nice big fish. I really wonder if the neons didn't bring some disease - why don't I quarantine new fish? You'd think I would have learned my lesson.

And in terms of life, the plant tank is full of Macropodus fry. I was hoping if I didn't feed them they wouldn't make it, but that isn't the case - there seems to be enough in there for them to eat...protists feeding on a healthy growth of algae and bacteria, I suppose.

Sunday, 2 September 2007

Major changes

Saturday saw major upheavals in the world of my tanks.

I have wanted to reduce my platy population for months, and I am (obviously) overrun with Macropodus. For a long while now Linz promised a friend of hers both platies and Macropodus, but never remembered to drop them off. At last today we did just that. So we managed a substantial reduction in the population in the big tank. To celebrate that change, I went out and bought a few neon tetras. Hopefully they can handle the water conditions in there (the water is too hard and too alkaline for their liking, quite honestly) - I got 5, I'm hoping at least 3 survive. I'm hoping to keep five (or more) of them, but I really don't want fewer than 3.

When the angels caught sight of the neons it's obvious that they thought "food!" It was interesting to see them hunt - since all four of them moved in on the neons, they were kinda cornered. Luckily, the neons are really too big to be food for these angels, otherwise I would have had to get them out of there, quickly. I also moved the pair of Macropodus out of the plant tank into the main tank, where hopefully (a) they will stop breeding, and (b) they will grow up a bit (so I can find a good home for them). There are a few fry swimming around in the plant tank - you never know, with all that algae, there may be something for them to feed on in there. (I rather doubt the Otocinclus will hunt them).

In other news: I got new bulbs for the main tank. They are supposed to provide a better spectrum for plant growth. But the problem isn't only spectrum, it's total light availability. I also got a bag full of brine shrimp at the pet store today - fully grown brine shrimp. The fish loved them, especially the young Macropodus in the breeding tank.

Wednesday, 29 August 2007

Macropodus fry

The Macropodus nest was in a difficult place to see easily, so it was hard to see if there were eggs, but after a few days I started seeing the fry. Today there are 30-40 fry (maybe more) on the glass below the nest. Now I have the great challenge - do I feed them? I don't want to - I have more Macropodus than I know what to do with. On the other hand, I don't feel comfortable with the idea of just letting them starve to death (letting them get eaten doesn't upset me, but letting them starve does, for whatever reason.

The other issue is algal growth. An awful lot of algae has grown along the glass in the tank - mostly along the right side (where the light is) especially along the back (which is against the window). I'm also getting algal growth (maybe cyanobacteria) along some of the gravel. On one hand, since my main interest is plant growth, this should not be a bad thing. On the other hand, the algae can overgrow the plants. One solution might be more plants, another is to get some more Otocinclus (since I only have one in the main tank, they could move over once they have acclimated and knocked the algae back a bit).

Sunday, 26 August 2007

Macropodus: The Next Generation

To serve as a nitrogen source (and create some circulation in the plant tank), I added a few of the baby Macropodus from the breeding tank. A quick pass netted four fish - the largest one, a male, and three smaller ones that appear to have been females. Once he realised that he was the biggest male in the tank, the male Macropodus got to work nest-building and displaying at the females. On Saturday, after less than a week in the tank, he had a fairly large nest. Over the course of the evening he and the largest female have started mating. Although they are still rather small, they appear to be successfully producing eggs - perhaps 3-5 of them are visible floating around after most of their "rolls". While for rather obvious reasons I don't want any more Macropodus (I still have about 30 of them in the breeding tank), it's still pretty cool to see the fish you bred breed.

On a more focussed note, the plants seem to be growing quite well. The light intensity is high enough (at least on one end to the tank) to produce reddish foliage. There has also been noticeable growth over the last week. It really suggests that what I need most in the main tank is better lighting.

Wednesday, 22 August 2007

New tank

After getting home from Michigan I launched into the big clean up - two major water changes in the main tank, addition of some rocks, and the addition of a lot of new plants. I also changed one of the bulbs in the "breeding" tank to a compact fluorescent bulb, since the original bulb had blown.

When I went to Petsmart to look at plants I realised that they had fairly cheap 10 gallon tanks (sans heater, pump, lights, or lid). Since I was already thinking about setting up something to try to revive all the uprooted plants in the main tank (that had taken to a floating existence), it seemed like a really good idea. So I bought a 10 gallon tank.

Since I was only planning to use the tank for plants, I figured I could use a soil base. Unfortunately, without thinking too much I used potting soil. Bad idea. It turned out that potting soil is (a) not soil (it's wood chips and compost), and (b) it floats. So that didn't work too well. I later read that if you use soil, you need to add about an inch of gravel above it (and, I suppose, make sure the gravel layer isn't disturbed when you add the water). Anyway, I ended up getting some aquatic plant "soil" from Home Depot - it's porous, fired clay. Hopefully it will do the job of a rooting medium.

Once I established the tank I realised that it needed a nitrogen source (fish waste) so I eventually added a few "baby" Macropodus. Since they are air breathers, I figure the lack of circulation shouldn't bother them. Now I just have to ensure adequate light and CO2 - not the easiest tasks in the world.

Saturday, 7 July 2007

Butterfly (or Skipper)

A slightly out-of-focus lepidopteran that posed for a picture at church (Floyd says it's probably a skipper)

Friday, 6 July 2007

Picky eaters

My angels, which started out as tiny little things, have grown into quite large fish - probably over 4" long counting the main part of the tail. I have these sinking pellets for the corys which the angels have taken a liking to - they swallow them whole if then intercept them on the way down. So, thinking that they could use some larger food, I bought them some floating "cichlid pellets". And the angels are totally uninterested in them. When I throw the pellets in, the platies go for them (but can't do much with them) and once they soak a bit the "baby" Macropodus will eat them...but the angels seem uninterested.

Tuesday, 3 July 2007

Still there

It would appear that I still have fish!

I finally cleaned the tank for the first time in far too long and it appears that I still have most of my fish. There's only one Otocinclus left, but I hadn't seen any for weeks. And I think one of the baby Macropodus didn't make it.

Cleaning and a water change (and more importantly, addition of new water) has brought the tank to life. The platies are going crazy. Amazingly, in a tank full of semi-aggressive fish (seven Macropodus in there right now) it's the platies that are doing the most fighting. One of the "younger" males seems to be challenging the largest of the "older" males for dominance. Fresh water always brings platies to life - not that the males don't harass the females all the time anyway.

I'm really not sure what the deal is with the female platies. I have yet to see any more babies, but in the current set-up, I doubt they would survive (the Macropodus and the angels are good hunters, and there are just too many of them). While I was convinced that I had never seen any of the females get any slimmer, I am no longer able to say that definitively. I just didn't pay enough attention to them for a length of time - and some of them don't seem as fat as they used to be. One of them has gotten huge.

Thursday, 17 May 2007

Updates

I haven't said much in a while. The main news:

* The Macropodus fry continue to grow quite well. I have introduced the two largest ones into the main tank a couple weeks ago, and three smaller ones a few days ago. The first two babies that I introduced have grown well - the larger one was almost as big as the smallest platy when it was first introduced into the tank - it's grown quite a bit since. Two of the new ones are doing ok, but I haven't seen the third one (which was smaller) - it' s possible that it's still hidden in the floating vegetation, it's also possible that it didn't make it.

* The male fighter, which was unwell since the start of the Ich outbreak died a couple weeks ago. He seemed to have swim bladder problems, and they got worse to the point where he could not stay afloat. Eventually we found some medicated food, and we fed it to him for a few days. By the second day he was looking fine, able to swim normally again. The day after he was dead.

* The female platies continue to get fatter. They look terribly pregnant, but there's no way (even given the strange breeding habits of live bearers) that they could still be pregnant after all this time.

* The adult Macropodus laid eggs every weekend for four weeks straight. The eggs hatched after about 24 hours every time, except the last time, when (after I turned the temperature down) they took a little longer to hatch. None of the batches of fry made it very far - the first one was eaten by the male Macropodus, the last two were eaten by the Angels once the Macropodus began to do a less good job of protecting the fry. They have continued to make a show of considering mating, but his attempts at nest-building have been pretty half-hearted.

* After staying small for a few months, the black Angel has done a lot of catching up, and while it is still smaller than the rest of its cohort, the size difference is no longer so striking.

Thursday, 3 May 2007

Mushrooms

Just east of the bus stop there was a tree that they took out early in the Fall. After some rainy weather, there was a burst of mushrooms which seem to map out the roots of the now-removed tree.

South from George Lynn Cross

Tuesday, 24 April 2007

New pictures

Actually they're about a week or two old, but I just downloaded them from the camera. I also went back to some of the older postings and added pictures. The largest of the angels with three of the "baby" platies (now all grown up).

Two of the original corys (sold to me as Corydoras aeneus, but clearly some other species).

One of these non-aeneus corys, with what I believe to be a true C. aeneus and a Panda cory (C. panda).

Monday, 23 April 2007

Fry update

There are quite a few Macropodus fry around - most of them are clinging to floating vegetation, but there are a few free-swimming individuals. That raises a question - are two-day-old fry going to be doing any swimming, or are these a mixture of newborns and 10-day-old fry? After I saw the male Macropodus eat most of the fry, I assumed that there were none left. While that still seems more probable to me, it's also possible that there were survivors of the original batch. I'd say "we'll see", but no, not really - the odds of many fry surviving in the community tank is pretty slim, and even if they do, the radically different growth rates that I saw among the first batch of fry make it impossible to connect size with age.

Saturday, 21 April 2007

Empty nest?

Looks like the Macropodus nest is empty. I didn't see anything in there this morning. Linz mentioned that the male didn't seem to be doing a very good job of keeping the eggs in the nest either. Oddly, he still seems to be defending the nest.

Update: Turns out that I was wrong - there were actually quite a few fry in the nest. So will the male Macropodus eat the fry tomorrow? Should I leave the lights on tonight, so that he doesn't have to gather up so many fry (and end up "forgetting" to return them to the nest like last time), or should I switch the lights off and maybe give a few of the fry a chance to escape into the vegetation, which is now considerably more dense than it was last weekend (thanks to the plants I got from Bob)?

Update II: As of Monday morning, there are still quite a few fry around. Most of them have left the remnants of the nest and are on the underside of a large Echinodorus leaf that's floating on the surface of the tank. While the male Macropodus was still defending his portion of the tank, I couldn't tell if he was doing anything to "manage" the babies.

Friday, 20 April 2007

Macropodus fry


The first batch of fry are doing well, but the size disparity is getting larger. Most of the fry are "average" size - around 6 mm long. Several are smaller than average - around 4 mm long. And some are much larger than usual - over 10 mm long. [Update: The large ones are over 14 mm long]

It's the giants that are really interesting. Not only are they about twice the length of average fry, they are also 4 or 5 times the overall size of the average fry. At least one of them appears to be an air-breather (the labyrinth organ doesn't develop until the fry reach a certain size).

I'm interested in what the evolutionary strategy is here - or whether there is one. Floyd asked the question of whether there is some sort of advantage to having some fry remain stunted - perhaps as a food source for their larger siblings. While that might explain the smallest ones, it really doesn't explain the very large ones. There's a continuum of body sizes, but the very large fry seem to be outliers.

I have no idea whether this is typical or not. It's possible that these are truly unusual individuals, but it's also possible that this is a normal strategy for Macropodus. If so, it makes me wonder whether this could be viewed from the perspective of asynchronous germination in seeds. The normal way to interpret this would be as some sort of scramble competition - that the most successful strategy is to get big as quickly as possible, because faster growth allows you to outcompete your siblings and escape many predators (including your parents).

The problem with this interpretation is that getting big probably isn't a winning strategy for a territorial species living in a limited environment. Chances are, not only is reproduction only an issue for a fish that can claim a territory, it's also likely that reaching adult size is only an option if a territory becomes open (much like a tree colonising a gap). If that is the case, then growing large quickly doesn't guarantee success - it only represents one out of a range of strategies. It may be that some fish get big quickly to occupy an immediately available territory (if one exists) while other mature more slowly, with the "objective" of staying to occupy a territory that becomes available later on.