Thursday, 31 January 2008
Source: Practical Fishkeeping.
Her first word of advice is not to stock tanks too quickly - wait for them to cycle. When I first kept fish, back around 1980, I was unaware of the concept. I don't recall it being in any of my fish books. When I returned to the hobby last year, it was something I was made aware of almost immediately - quite rightly, it's one of the first things they tell you are the pet store. That said, I still messed up with the whole cycling thing - it would have saved me (and my platies) a lot of stress if I had understood the time course a little better. I had fin rot and "shimmying" fish - because the tank wasn't yet cycled. While everyone wants fish as soon as possible, fishless cycling is much less stressful on the aquarist. But who really knows that right when they start off?
Once you have a tank that has cycled, you still need to add new fish slowly. More fish means a larger input of nitrogenous compounds. Since the bacterial populations will be limited by food availability, adding too many fish too quickly, even to an established tank, can cause a spike in ammonia or nitrite levels.
Her next piece of advice seems pretty straightforward as well - don't overfeed. But overfeeding is an elusive idea. If you read a pack of fish food they will say "no more than the fish can consume in three minutes". But that really depends on the fish. Some fish will take a couple minutes to even notice the food. Others will just keep eating. If I could get flakes that would float for three minutes, I suspect that my Macropodus would consume their own body weight in food.
Youngs has some interesting advice about feeding that I hadn't come across before. "How often should I feed my fish?" is a common question. Some people say three times a day, some people say once a day or less. Why such diversity of answers? Probably because it depends on the fish you're keeping. Youngs advises feeding small fish like tetras and guppies several times through the day. Larger fish should be fed less frequently. In addition, herbivores need to eat more often than carnivores. This is all pretty obvious once you think it through, and it's probably something a lot of people know intuitively. But again, it isn't something I remember coming across before.
She has some fairly standard things to say about lighting and algae, but again, says them well. Good advice on acclimating your fish, and on suitable tank mates. She advises redundancy when it comes to heating and filtration - two filters, two small heaters. Why small heaters? Because if one sticks on the "on" position, it won't heat the tank up too quickly. Common sense. Hadn't thought of it.
The last point she makes has to do with stocking levels. If you visit discussion boards, most people talk about the 1 inch per gallon rule as the upper level when it comes to stocking, which is why I was surprised when I read that an article in the February issue of Tropical Fish Hobbyist which suggested that you start a 10-gallon tank with "10 neon tetra-sized fish" (1 inch per gallon) but that you could eventually go to double that once your tank was well-established. Bending the rule a little - I'm sure most people do that. But going to double that? I was surprised. So it was nice to see Karen Youngs give similar advice
Nowadays with better filtration it is hard to give an exact figure, but PFK recommend the following:Getting that sort of advice from one source seemed iffy to me. Getting it from a second, independent source (and getting a more nuanced answer) makes me feel a little more inclined to integrate that factoid to my pool of knowledge.
Tropicals: 1” per gal/ 2.5 cm per 4.55 l initially, then up to a maximum of 2” per gal/5 cm per 4.55 l after six months.
Coldwater: 1” per gal/2.5 cm per 4.55 l.
Marines (fish and inverts):
1” per 4 gal/2.5 cm per 18 l.
Marines (fish only): 1” per
2 gal/2.5 cm per 9 l.
Ponds: 10” per 100 gal/25 cm per 455 l.
Wednesday, 30 January 2008
There are a few options. One option is to try to turn it into a proper display tank. It's the most visible tank in the house, so it might make sense to try to make it as pretty as possible. But what I really want is a breeding tank, a place to try my hand at getting corys to breed. The question is - which ones do I try?
The biggest group, the six Corydoras trilineatus, are too young and don't seem to be thinking about breeding. The pandas are good candidates, as are the Cw008s, since I appear to have a male and a female, and they seem interested in one-another. I don't know what sort of conditions Cw008 would want for breeding, but it's worth trying the standard cory setup - regular water changes with water a little cooler than the tank. It's probably more important to give them a rich diet. The biggest challenge is probably to catch them without trashing the entire tank.
There's no guarantee that I'll be able to get them to breed, and if I do, if I'll be able to raise the fry. But I don't want to make the same mistake I made with the Macropodus - that left me with over 60 fry to find homes for. Since Cw008 (assuming that I have the ID correct) is less common, I'm guessing that there's an appeal in rarity. On the other hand, there's obvious demand for pandas - things with mass appeal are likely to be easy to get rid of.
The interesting thing about this set-up is that it brings corys right up to the surface. While they will swim up and down my Cabomba plants (which reach the surface of the tank as well), they don't spend much time on any particular plant. On the other hand, if they make it up to the floating mat, they can spend a good bit of time exploring it. Since the interior is too dense for any of my fish to get into, it's likely to provide predator-free space for small inverts. Since my tank is deficient in fish that use the upper portions of the tank, it's nice to see the corys active near the surface.
Like anything of the sort, the information online is spotty and inconsistent. So short of buying a subscription to Ian Fuller's Corydoras World, it's likely to be difficult to get consistent information. They are described as both "easy" to breed and "difficult" to breed. Of course, it may be a matter of context - relative to guppies, they are hard to breed, but compared to some of the more difficult corys, breeding them may be easy. A couple people say that they produce small spawns - 5-10 eggs - but others say 100-300. Of course, spawn size could depend on a number of things, including whether you see the eggs before other fish eat them. It's also likely to be a function of the condition the fish are in, and may be related to water quality. I saw one comment about them liking a higher pH than is typical of corys (if true, that would be a bonus for me).
Sunday, 27 January 2008
Saturday, 26 January 2008
If we can get rid of the Macropodus, I'd really like to try to breed either the pandas or the Cw008s.
When their parents bred for the first time (in this tank) the tank community was very different - there were a dozen or so platies, and four angels. Now there are no fish near the size of the male, and the female is at least as big as the other fish. There's also a lot more structure to the tank - the area around the nest is well vegetated.
The female has taken to chasing the other female Macropodus between matings, not that she doesn't do that anyway. In the past, after they were done mating, the parents established a two-tiered cordon around the nest, with the male keeping the female away from the nest, and the female keeping the rest of the fish away from the male.
I'll be curious to see how this works out.
Thursday, 24 January 2008
Wednesday, 23 January 2008
Cleaning the sponge produces a huge crowd of these guys - and a layer of "dirt" (aka POM - particulate organic matter). I need to find some way to separate the inverts from this stuff. Right now I have them in a small cup floating in the tank. While this allows the dirt to settle out, it doesn't help much because the inverts prefer to feed in the POM. Is there some way to sink the cup but not disturb its contents to much?
Here's a shot of its body. Unlike most other spotted cory's, it's got light spots on a dark body, rather than the other way around.
And here's a picture with one of my other corys - the one on the left I believe to be Corydoras trilineatus.C
Tuesday, 22 January 2008
Monday, 21 January 2008
Sunday, 20 January 2008
Saturday, 19 January 2008
Thursday, 17 January 2008
In their favour, the Glowlights tend to school, and when they move together, it's an impressive sight. That probably means that I need a lot more than six of them - the more there are, the bigger the impact. In addition, of course, they are also likely to be bolder in larger groups. Hopefully, as they get more accustomed to their new homes, the Glowlights will start using more of the water column. One can hope, anyway.
Wednesday, 16 January 2008
That said, I'm pretty happy with my choice thus far. They look pretty good in my tank, and they are schooling nicely. They're quite active and add colour to the tank. Unfortunately, they appear to prefer the lower third of the tank. They are venturing into the upper parts of the tank, which is encouraging - hopefully, as they grow more comfortable they will make more use of those areas.
Tuesday, 15 January 2008
Fuller finds it dubious that such different forms are the same species, especially since they are found in such far-flung locations as Trinidad, Argentina and Peru, in river systems that have been unconnected for millions of years. I suppose a good molecular study might be able to shed some light on the relationship within this group - at the very least, whether they form a monophyletic group or whether other species are nested within the group. If they are sister taxa, then the matter of whether they are the same or different comes down to the opinions of lumpers and splitters.
I had removed one of the males in the main tank over the weekend because Camallanus worms were, once again, hanging out of him. This was obviously not a re-infection - these were worms that had survived the treatment. While I need to do a second round of treatment, I think I will go with levamisole (provided that I can track some down). Still, the idea of breeding drug-resistant worms did not sit well with me. Two of the others had holes in their sides. They had them when we got home from Christmas, and they had not healed. Anyway, the end result was that I euthanised five fish. Tempting as it was, I couldn't flush them or stick them in the freezer. Long ago, Brian said that there were two ways to kill a rat - one was humane to you, the other was humane to the rat. I decided that speed was of essence, and I decapitated them. Quick, yes, but very difficult on me.
Anyway, I added two males and two females to the main tank, and returned three males (and eight females) to the Macropodus tank. So now the males in the main tank are battling for status. The old male is twice their size, despite being their littermate. The older female though is only about the size of them new males, and is much larger than the new females. She is chasing the newcomers, both male and female.
In the Macropodus tank, the males seem invisible, while the females are trying to reestablish their order of dominance. I still have too many of them, but it's a move in the right direction. With more space and (hopefully) improved water quality, these guys might do some growing.
Monday, 14 January 2008
In this environment of perpetual darkness, the eyes of [the ancestors of blind cavefish (Astyanax mexicanus)] were of little use and as generations passed, they disappeared entirely. They now navigate through the pitch-blackness by using their lateral lines to sense changes in water pressure.
But there is a deceptively simple way of restoring both the eyes and sight that evolution has taken, and Richard Borowsky from New York University’s Cave Biology Research Group has found it. You merely cross-bred fish from different caves.
So how does this work? Obviously the lack of eye development is the result of different mutations in different caves. In different caves, different gene mutations resulted in the loss of eyes.
Wednesday, 9 January 2008
Tuesday, 8 January 2008
Here's one of his many videos. I really like the fact that you can get a feel for the species in its natural habitat. It would definitely be an asset to anyone setting up a South American biotope tank.
Monday, 7 January 2008
Given all the open water, I would really like a nice school of tetras or something of the sort. But two trips to the pet store have failed to turn up anything that really jumped out at me. I'm tempted to get some more angels, but I just don't want large fish - they really end up limiting your options when it comes to smaller fish. I'd much rather have a school of small fish than a handful of big ones.
Sunday, 6 January 2008
This is one of those things that fascinates me. While amateur botanists (and, for that matter, an awful lot of professional plant scientists and ecologists) tend to treat nomenclatural changes with disdain, fish keepers appear different - many seem happy to keep up with the "latest" names. Part of it may come from the fact that fish keepers are often on the leading edge of discovery of new species - newly discovered loricariid and corydorinid catfish are assigned L and C numbers while the hobbyists wait on systemtists to describe the species. But I suppose tropical fish keepers experience tropical diversity in a way that few other people in the temperature zone ever do. And it's a short step from "I want to know the name of my fish" to "I want to know the current name for my fish".
I actually went to the pet store in search of some Otocinclus - the February issue of Tropical Fish Hobbyist has a good article on them by Gary A. MacDonald of TropicalResources.net. MacDonald says that not only are Otocinclus very social fish (and recommends that they never be kept in groups of less than three), but when the groups exceed 12 individuals interesting dominance hierarchies emerge. Having read that, I felt the need to expand my collection - after all, I only have two in my main tank. Unfortunately, the pet store only had two left. Since I have no way of being sure which species of Otocinclus I have, I would rather purchase a bigger group - that way I'm more likely to get several of the same species.
Friday, 4 January 2008
Once I brought them home and released them into my tank*, they brought my resident corys to life. Adding some food helped, but the addition of smaller, younger, more active fish brought the whole tribe into action.
I saw at least three of my original four corys, and the five newer ones (two panda corys, two unknowns). I also saw both of my Otocinclus, and at least two of my kuhli loaches. So while I lost the angels, the fighter, my three neon tetras and a few Macropodus (0-2 males and 1-2 females), things look better than I initially thought. On the other hand, the plant tank seems empty - there seem to be a lot less than 9 pygmy corys, though the fact that they have moved from their original congregation spot makes it difficult to figure out how many there are.
*Yes, I realise that given my recent experiences I should have instituted a strict quarantine system. But, at this stage, I find it hard to care too much.
Thursday, 3 January 2008
On the other hand, I lost a lot of fish. I came home last night to a house that stank of rotting fish. In the main tank, I lost both angels, my fighter, and all of my neons. I lost at least one Macropodus, probably more. I haven't determined what happened to the corys and the kuhli loaches - I saw one kuhli loach, all three of the panda corys, and several of the others. I see one Otocinclus, but I'm not sure about the second one. The water was horrible when I got home - I'm impressed that any fish survived such polluted water.
In the plant tank, I see a lot of shrimp, two Otocinclus and a few of the pygmy corys. I haven't seen many pygmy corys,; I'm hopeful, but concerned. The tank had very heavy algal growth - probably a consequence of having the lights on 24 hours a day for almost two weeks.
I haven't taken a good look at the Macropodus tank. There are at least a dozen fish in there, but it's very messy and overgrown. I haven't yet tried to tackle that one.