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.

Another batch of eggs

The Macropodus laid another set of eggs last night. I don't have anywhere to put the fry, so I suppose they will also live a short life.

Wednesday, 18 April 2007

Macropodus fry

While the second batch of fry succumbed to parental cannibalism, the older ones are doing well. My brine shrimp yields have been pretty good, so they have been eating fairly well. What's remarkable is the differences in growth rate among them. There are several fry that are considerably smaller than the average, and there are a couple that are considerably larger than average - most notably, one giant who is 2-3 times the size of its siblings.

I ran the filter for a little while again yesterday - although the fry were still using the entire water column, I was a little concerned about oxygenation and BOD (biological oxygen demand). The fry are unlikely to be air breathers yet, and there's sure to be other decomposable material in the water. Added oxygen is also going to benefit the bacteria involved in nitrogen cycling (which are mostly aerobes). Still, I don't like the leave it running too long, since the fry aren't yet strong enough swimmers to deal with the water currents set up by the filter.

So while still water is likely to reduce the energy demands of the fry, it also reduces the oxygen content of the water (and possibly the ammonia and nitrite concentrations). I don't know if it's a net benefit or cost. On the other hand, the Ludwigia seem happy with the stillness and the falling water levels. Several stems have emerged above the water level, and at least one of them has flowered. The breeding aquarium has taken on something of a pond appearance, which I really like.

Monday, 16 April 2007


I decided that leaving the light on overnight (as I did on Friday night) probably wasn't the best idea (if nothing else, I probably didn't sleep as well with the light on), so I turned it off Saturday night. On Sunday morning when I turned the lights on, the babies had scattered quite a bit. The male Macropodus diligently started gathering them up and bringing them back to the nest, but af some point he stopped spitting them back into the nest. He then went to the nest and started gather those ones up as well.

A few hours later there were still a number of them left, but my this morning I couldn't see anything left of the second batch of baby Macropodus.

Saturday, 14 April 2007

Day 3

I left the light on in half the tank tonight, to make it easier for the Macropodus to keep track of the babies. As soon as I switched off the light in the other half of the tank, all of the platies (and several of the angels) moved into the lit half of the tank, brining them into what the consider their territory. That said, most of the platies ended up in the deep water below the nest, which the Macropodus ignore.

The nest is full of fry. Not sure what happens next - they are supposed to be free swimming by day 3. I'm not sure what happens then - if he will still protect them, and if he will be able to protect them.

Friday, 13 April 2007


Overnight, with the lights out, the male Macropodus appears to have done little nest maintenance, such that when I put on the lights this morning there were eggs and babies all over. Since then he has been diligently collecting babies and eggs, while chasing everyone else away from the area of the nest. In this he has had the assistance of the female. Between the two of them they have claimed about half the surface area of the tank and maybe a third of the total water volume (they aren't bothered by fish more than about a foot under the nest).

While the male seems to have a good grasp on his role, the female seems a bit less sure what to do. Unlike him, she is still eating - may be eating eggs and fry as well (I have seen her gather up errant fry, but I haven't seen her return anything to the nest). In addition, the male chases her when she gets too close to the nest. On the other hand, she is doing a good job chasing everyone else away from the nest. She seems to have an especial dislike for the angels - she goes to the far end of the tank to find angels to chase.

I noticed that the fry tend to attach to surfaces - not just bubbles, but also the glass or plant stems. I suppose there's survival value in that - they are less visible if they attack to vegetation.

Thursday, 12 April 2007

Macropodus nest

The nest is built under and around an Echinodorus leaf that's right on the surface of the water. The male is being an attentive father, although he leaves the nest to chase the female every now and again. I'm not sure if he still wants to mate, or if he is keeping her away from the eggs.

The female, on the other hand, is behaving oddly - she has taken to chasing the angels, which is interesting, since the larger angels are about her size. She ignores the smaller fish, but seems determined to keep the angels out of the portion of the tank that includes the nest. The male, on the other hand, seems to ignore the angels pretty much, but chases any platies that get too close.
A shot of the nest through the side of the tank (and a nice shot of the camera, reflecting off the glass)

These are taken from above. The eggs are visible in the lower picture.
And here's the male Macropodus, sitting below the nest. No longer in breeding colours, he seems pretty washed out.

Back at it again

Less than two weeks after the bred, the Macropodus look like the want to breed again. The male has built a nest, and the female is hanging around it in a fairly interested fashion. If they do breed again, I don't have anywhere to move them - I just don't have another tank. Sadly, the eggs will probably end up as fish food. I'm more worried about how the male will react - he's likely to go crazy trying to defend his nest, and may actually hurt some of the other fish (he is, after all, easily the largest and most aggressive fish in the tank).

Well...we'll see what happens.

Update: Turns out that events had overtaken me - he already has a nest full of eggs. They must have mated last night. Surprisingly, he seems to have done a pretty good job of defending the nest - it hasn't turned into a free-for-all feeding place.

Tuesday, 10 April 2007

Macropodus fry

The Macropodus fry population seems to be doing well. I have started feeding them brine shrimp, but my production system doesn't produce all that many, and unfortunately I didn't factor in the issue of sustaining production with only a single culture going - soon I will have to start over, and that will result in a 24-hour lag in production.

The fry have grown considerably, but they are still very small. The fry which congregate in the Elodea look like a fruit flies. I have subdivided the fry into several groups (the Elodea group, the open-water group, the heater group) but it's probably more a matter of my perception than it actually is of any subdivision among them.

It's quite interesting to watch the fry hunt brine shrimp. Some of them appear to be more experienced hunters by now - they see the brine shrimp, head straight for them, and gobble them up. Others seem less sure what to do - they see them, follow them for a while, and then pounce. It may be an experience thing - when I first added the brine shrimp all the fry seemed uncertain - they ignored them first, then followed them for a while, and then finally pounced (feeding is always a jerky motion for them).

I'm a little concerned about water quality in the breeding tank. I have had the filter off for over a week now, so both oxygen levels and biofiltration are likely to be lagging. I'm wondering if I should buy a pump and air stone, so that they get the agitation without the intake issues. I suppose I could also find some fine fabric to put over the intake of the filter - switching on the filter would radically alter the fry's world. I also need to think about some other food options - egg yolk, or finely ground fish food - something to supplement brine shrimp (since I really don't have a high-throughput system, or the means to set one up).

Monday, 9 April 2007

More on Ich

Searching for information about fish online has been enlightening. There's an awful lot of information out there, but it's often hard to gauge reliability. I realise that shouldn't be a revelation to me, but the truth is that I have rarely looked "blind" - I usually either have a sense of what I am looking for, or I have restricted my search to sources I feel comfortable trusting. This hasn't been a viable strategy this time.

I initially got the impression that ich was a water quality issue - that the causal organisms were normally present in aquaria, but only became a problem when fish were otherwise stressed. That proved to be a misconception - Ichthyophthirius multifiliis appears to lack a dormant life stage, so it can only be transmitted by infected fish or by plants (or other substrate) upon which the tomont has encysted. The infectious trophont is the sensitive stage - this is the one that can be affected by medications, and it appears that the infectious trophont stage can't survive more than a couple days outside of the body. Hence the suggestion that they best way to "clean" a tank is to leave it fish-free for a few days. Of course this doesn't answer the "Typhoid Mary" question - are there outwardly healthy carriers of the disease? To some extent this is true - since the parasites tend to infect the gills, it's possible to have an infected fish that lacks the characteristic white spots. But these fish will still only remain infected until the trophonts mature and drop off. Are there dormant infections - ones that will remain in the trophont stage until the fish is stressed?

Sunday, 8 April 2007


The dreaded Ich (Ichthyophthirius multifiliis) has struck my community tank. And in the last day or so I have learned an awful lot about the disease.

Ich is a disease caused by a parasitic ciliate. I got the impression initially that it was a disease of low water quality - that the organism was usually present in aquaria, but only stressed fish suffered actual outbreaks. Turns out that bit of conventional wisdom is false - it's an obligate parasite, so any introduction needs to come either with living fish or live plants. I hadn't thought of quarantining plants (well, slightly, but not to any great extent).

So how did I get it? The outbreak seems to be confined to the platies, but it's almost impossible that they are the cause. Most of my platies were born in this tank - they were the first fish I got. So the true culprits must either be plants (which are, after all, my most recent purchases) or an asymptomatic fish ("asymptomatic" in the sense that I can't see the symptoms, although they could easily be on the gills). I've had my newest fish (the Otocinclus and the Kuhli loaches) for two and a half weeks, so they could be the culprits, as could the new plants.

Friday, 6 April 2007

"Trinidad Plecos" at Steve's

I'm guessing that a "Trinidad Pleco" is a Teta (Hypostomus robinii). Unfortunately, there were none in the tank at the time.

Update: According to PlanetCatfish, a Trinidad Pleco is Pterygoplichthys punctatus, a Brazilian species with no apparent links to Trinidad (at least not Trinidad and Tobago).

Wednesday, 4 April 2007

Macropodus fry

The male Macropodus is being a good father - I tried feeding him, and he reluctantly ate a little, but basically he's unwilling to eat when he has a tankful of fry. So when I saw him grab a baby I expected him to spit it back into the nest immediately. I was a little concerned when he paused for a moment, and then went up to the surface for a breath, but he then swam to the nest and spit the baby out, back into the nest.

The fry in the breeding box seem to be doing pretty well without parental care. Most of the eggs hatched - the biggest risk is probably drowning, but there's enough floating vegetation in the box to keep them near the surface. Water quality is another issue - the fry food, which was probably a bad idea to begin with, just sinks to the bottom and (presumably) rots. While the community tank, with its filter still on, is likely to have better overall water quality than the other tank (where I had to switch the filter off), the breeding box creates a pool of stagnant water. Well, these are fish that evolved in stagnant pools of water, so hopefully they can handle things like that.

Food is another concern. The community tank is starting to get "furry" - there's a lot of epiphyllic algae on the leaves and stems of th plants. The plants in the breeding box are likely to be a good source of food for the fry. The breeding tank is never and cleaner, with large areas of open water. I'm less sure about the food supply in that tank. It's also hard to get the fry food anywhere near the fry. I've been adding my "infusoria", but I'm by no means certain about the sort of growth I'm getting in those containers. The weather has also taken a cold turn, and the bottles were sitting in an open window, so that's likely to have slowed growth of both bacteria and protists last night.

Tuesday, 3 April 2007

Breeding Macropodus

Whenever you read about breeding Macropodus, you see the comment that they breed easily, so I suppose I should not have been surprised that they did. I didn't expect them to breed in the community tank though - I figured it would have been something that would have required more effort on my part.

It would have been fun to let them breed in the big tank and let the babies fend for themselves. I think I like the platies more because they were able to grow up "by their wits", to survive in what was at the time a much less heavily planted tank. I like seeing a few bold fry emerging from the plants. Raising fry in a dedicated breeding tank is a bit less exciting, although the idea is still appealing. Granted, it's a bit presumptive to talk about raising fry when, thus far, you don't have any clue what you are doing or how you are going to keep them fed.


The nest is full of fry this morning - hundreds of baby Macropodus. The male has considerably expanded the nest as well.
Amazingly, the breeding box has babies as well - despite the obviously inferior conditions and lack of parental care (and a nest) there are also fry swimming around in there.

Monday, 2 April 2007

More eggs than bubbles

The new nest is a fraction of the size of the old one, and it seems like it has more eggs than bubbles. These pictures are from this morning, but he doesn't seem to be adding any bubble to the nest. I see this whole thing as a learning experience. If we get a some babies out of this, great, but if we don't, I hope that I can learn some about how Macropodus breed.


The male Macropodus was frantic in the breeding box, and he was paying no attention to the nest, while the female was still trying to mate with him, so we decided to give them a second chance in the small tank. The nitrites were down to zero, so I netted out the platies and moved the Macropodus over. By thing morning there was a small nest full of eggs, and they seemed to be done, so I moved the female back to the community tank. The breeding box still has eggs as well, although there aren't many bubbles left there. The eggs float, so I suppose we'll see what happens.

I'm really glad they bred, and I'm looking forward to the eggs hatching, but I really don't know what I would do with a crop of baby Macropodus. Not that I really have to worry about that - getting the fish to spawn is the easy part - raising the fry is far more difficult.

Sunday, 1 April 2007

Macropodus breeding

The Macropodus male started building a nest yesterday. I didn't think too much off it, but tonight the female took and interest in it and they started mating. Initially they didn't seem to be very good at it - lots of couplings, but no eggs. Then a little while ago we noticed that the male was going crazy chasing platies away from the nest (initially he hadn't been bothered my other fish examining the nest), which suggested to me that there were eggs in there. As I looked at it more closely I saw an angel come and pluck something out of the nest, and then one of the platies. There wasn't much I could do other than place the nest (and the male) in the breeding box. So now he's in there, frantically trying to get out, frantically trying to chase the other fish away...and he's pretty much letting the remains of the nest disintegrate. Oh well. I'm still hoping for the best. Macropodus are supposed to be fairly easy to get to breed, so maybe I'll try again in the small tank, once the tank is cycling properly. Anyway, here are some pictures of the nest before I damaged it by putting it in the box.