A while ago I tried to convince my pygmy corys to breed, but without much luck. Water changes (especially in coincidence with weather fronts) could get them to come out and "dance". Recently I have noticed more complex behaviour, including what looked a bit like the "classic-T" behaviour that spawning corys adopt. But I had pretty much given up hope of anything actually happening.
Last night I noticed something moving at the front of the tank. Before it darted back into the thicket of Hemianthis I saw something that looked like a tiny tadpole, maybe 4-5 mm long. It took me a moment to realise what I had seen - fry! Over the next couple hours I caught another glimpse of it. Very cool!
Now, I can't say for certain that it actually was a baby cory - there are also a few Otocinclus in the tank, but odds are that it was a pygmy cory. Pygmy corys are considered easy to breed, while Otos are rather less easy. Also both fish are easier to breed in groups - I had 7-10 corys in the tank, but only three Otos (and one, I suspect, is a different species from the other two).
Showing posts with label Otocinclus. Show all posts
Showing posts with label Otocinclus. Show all posts
Wednesday, 7 May 2008
Tuesday, 26 February 2008
Otocinclus notes
Otocinclus, the dwarf suckermouth catfish, is a very popular algae-eating catfish. The seventeen species of Otocinclus (often called Otos) are very popular for algae control. Unlike their large cousins, the Plecos, Otos remain small and are not boisterous enough to cause damage to plants. Although they are often purchased singly for algae control, Otos are social and should not be kept in groups of less than three. They are native to South America east of the Andes mountains, in streams that drain into the Amazon, Orinoco, Paraguay/Parana rivers, and in streams that drain into the Atlantic in southeastern Brazil. They are notably absent from the Guianas.
Otos are small - they range in size from 16.5 to 43.8 mm (0.6 to 1.7 inches), not counting the tail. Females are 10-20% larger than males, and have a broader body, especially when they are in breeding condition. [Read the rest of my post at HubPages.com]
Otos are small - they range in size from 16.5 to 43.8 mm (0.6 to 1.7 inches), not counting the tail. Females are 10-20% larger than males, and have a broader body, especially when they are in breeding condition. [Read the rest of my post at HubPages.com]
Monday, 11 February 2008
Using biogeography to guess at species identity
Just over a week ago, I found two Corydoras habrosus mixed in with the Otocinclus at the local Petsmart. Since C. habrosus is restricted to the Amazon basin, it struck me as a useful clue in trying to identify the Otos. In his 1993 monograph on the genus Otocinclus, Scott Schaeffer mentions that only two species of Otocinclus are found in the Orinoco basin - O. vittatus and O. huaorani. I'm leaning a little more towards O. vittatus, but I really need to take a better look at them.
Sunday, 3 February 2008
Otocinclus tank
While many aquarists value Otocinclus catfish as algae eaters, they seems to be looked on more as a part of the tank maintenance system than as "pet fish". And quite frankly, my impression of them was that they just weren't the most exciting fish. While I found them interesting, they never seemed to do much. So I was intrigued by an article in the February issue of Tropical Fish Hobbyist by Gary MacDonald. Not only did he say that they are very social fish, he also spoke of interesting dominance hierarchies in groups of 12 or more. While this caught my attention, I didn't feel like I had room for another dozen or so fish in my main tank. With the former Macropodus tank available, I ended up buying some, pretty much on a whim.
From what I've read, one of the major concerns about pet store Otocinclus is that they are often starving - they are herbivores, and are likely not to have had enough to eat for a while. There is also the stress involved in being caught and transported home. Once I got them into their tank, they all went for the bottom or the sides of the tank and just suck there. But after a few hours they were extremely active, swimming all around the tank, presumably examining surfaces for algae. They have slowed down a little since then, but they remain much more active that any Otocinclus I have seen previously. Of course, they are also very young - I wouldn't be surprised is they slowed down a lot as they matured. It'll be interesting to see what happens.
From what I've read, one of the major concerns about pet store Otocinclus is that they are often starving - they are herbivores, and are likely not to have had enough to eat for a while. There is also the stress involved in being caught and transported home. Once I got them into their tank, they all went for the bottom or the sides of the tank and just suck there. But after a few hours they were extremely active, swimming all around the tank, presumably examining surfaces for algae. They have slowed down a little since then, but they remain much more active that any Otocinclus I have seen previously. Of course, they are also very young - I wouldn't be surprised is they slowed down a lot as they matured. It'll be interesting to see what happens.
New fish
For no reason in particular, I visited our local Petsmart today, and was rewarded with a rare treat - in a tank of Otocinclus there were two dwarf corys - not pygmaeus, but I knew it must by one of the others. It turned out to be Corydoras habrosus, a Venezuelan species.
That pretty much decided the fate of the former Macropodus tank. I couldn't put the new corys into the main tank (they're a bit small to cohabitate with adult Macropodus), and I didn't want to add them to the plant tank without quarantining them first. So that left the former Macropodus tank. And since I didn't want to leave them as the sole occupants of the tank, I took the opportunity to buy a dozen Otocinclus, as Gary had recommended.
That pretty much decided the fate of the former Macropodus tank. I couldn't put the new corys into the main tank (they're a bit small to cohabitate with adult Macropodus), and I didn't want to add them to the plant tank without quarantining them first. So that left the former Macropodus tank. And since I didn't want to leave them as the sole occupants of the tank, I took the opportunity to buy a dozen Otocinclus, as Gary had recommended.
Sunday, 20 January 2008
Sunday, 6 January 2008
Otocinclus and Corys
I found another two of the "trilineatus-type" corys at another pet store today. That gives me a total of six of them - hopefully it will get me some good schooling behaviour. I was looking for characins again, but once again nothing jumped out at me. Nothing but corys, that is. The two I bought were in a tank of "spotted Corydoras"; I have two of the other species, but I didn't want to buy too many fish today. I was also tempted to get some more Corydoras aeneus and maybe to finally buy some C. paleatus, but I managed to resist the temptation.
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.
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.
Thursday, 20 December 2007
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.
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.
- 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
- 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
Monday, 22 October 2007
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").
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").
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.
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.
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).
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).
Friday, 23 March 2007
Otocinclus pictures
This is a picture of the only survivor of the first set of Otocinclus. It was the largest of the group, which may mean that it had more reserves to make it through the transition, or simply that it was the healthiest of the group. It's entirely possible that the fish weren't that healthy to begin with, and that it wasn't the food supply in the tank or something else I was doing wrong. On the other hand, it may be entirely my fault.
This is the larger of the new Otocinclus. This fish has a pronounced hunchback. Not the normal sort of "sick fish" hunchback, but there is a distinct bend in the front of his spine. Not exactly a good sign (the problem with buying fish at Petsmart is the difficulty in saying "I want that fish"), but the fish seems active. He's also willing to swim among the corys and forage on the bottom of the tank.
Finally, this blurry picture is in response to this comment... an Otocinclus eating spinach.
Thursday, 22 March 2007
A plethora of "cleaners"
One of the Otocinclus has been missing for a few days. A second one was dead this morning. I don't know if food was the issue or whether it was a consequence of rough treatment when they were caught at Petsmart (the assistant was pretty rough on them), but I was down to one survivor. I felt torn about whether I wanted to replace the lost fish or not. I feel guilty about letting the fish die, and feel like, well, if I failed to keep them alive, what right did I have to kill some more of them. But I decided to give it another try, and I bought two new Otocinclus today. I also bought some Kuhli loaches, hence the title of my post. I've been fascinated with them since I saw them a couple weeks ago, and having read up on them I was very interested - they seem like really cool fish, although I worry that their burrowing behaviour will wreak havoc on my plants.
So, assuming everyone survives, I have thirteen fish that are species that people usually keep as "cleaners" - seven of corys of (I believe) three species, (one C. aeneus, three C. panda, and three unknowns), three Otocinclus, and now three Kuhli loaches.
So, assuming everyone survives, I have thirteen fish that are species that people usually keep as "cleaners" - seven of corys of (I believe) three species, (one C. aeneus, three C. panda, and three unknowns), three Otocinclus, and now three Kuhli loaches.
Wednesday, 21 March 2007
Otocinclus
In terms of interactivity, I think the Otocinclus rank last among my fish. Everyone else is at least aware of your existence when you feed them, but since these guys aren't interested in fish food, there isn't any reason for them to pay attention to me. As "sucker-mouth" catfish they are also different to the other fish - they will often just hang on the glass at the back of the tank for extended periods of time, or on the petioles of an Echinodorus leaf.
I bought three of them, and as recently as Saturday I was able to find all three, but the last few days I can only find two of them. It's possible that I lost one, although it's hard to say for sure, given the density of hiding places in the back of the tank. As the fish most inclined to sit still, you'd think that they'd be the easiest to photograph. Unfortunately, they tend to sit at the back of the tank, obscured by either leaves of bubbles. They're actually almost impossible to photograph.
I bought three of them, and as recently as Saturday I was able to find all three, but the last few days I can only find two of them. It's possible that I lost one, although it's hard to say for sure, given the density of hiding places in the back of the tank. As the fish most inclined to sit still, you'd think that they'd be the easiest to photograph. Unfortunately, they tend to sit at the back of the tank, obscured by either leaves of bubbles. They're actually almost impossible to photograph.
Friday, 16 March 2007
New fish
I added two species this week to my main tank- Otocinclus and Macropodus. How will this change the dynamics? I'm not sure.
The three Otocinclus are unlikely to have any impact on the community dynamics (except, of course, for waste processing and oxygen demands, which are, of course, valid considerations). The attracted some interest initially, primarily from the Angels, but they have since faded into the background. They hang around (literally) on the sides of the tank (usually the back) or the Echinodorus leaves and stems, and don't move too much. Hopefully they will keep the algal growth in check (not that I have a lot of algae, thanks, I'm sure, to my plant population). I'm a little more concerned about keeping them fed. I suspect that they will be ok, even if the algal growth is limited - I'm guessing they can eat the plants, if nothing else. Still, I have decided to try feeding them some "parboiled" spinach. The websites I looked at suggested using "plant clips" (which apparently clip onto the side of the tank) to hold the spinach/zucchini/brussel sprouts, but I just tucked the spinach leaves into the gravel. I added the spinach this morning, and so far there has been very little interest from anyone - two of the platies are paying some attention to the leaves, but the Otocinclus have not made it anywhere near the bottom of the tank. Maybe I really do need some sort of a "plant clip", maybe the Otocinclus won't venture onto the bottom of the tank. We'll see, I suppose.
The other new additions are a very different story. Two Macropodus (hopefully a male and a female) have impacted just about every aspect of life in the tank - among other things, bumping the male fighter off his post as "top dog" in the tank. Although they have a reputation for aggression, so far I have been lucky - they have stared down the fighters and chased the platies a little, but overall nothing too serious. On the other hand, the male is harassing the female a bit much...still, there's enough cover for there to get some peace, hopefully. She doesn't look terribly happy overall though.
The presence of other anabantids have definitely affected the fighters. Initially the male got a lot paler, and the female a lot redder. Since then, he has recovered a lot of his colour, and she has lost some of hers, but their behaviour has definitely changed.
The three Otocinclus are unlikely to have any impact on the community dynamics (except, of course, for waste processing and oxygen demands, which are, of course, valid considerations). The attracted some interest initially, primarily from the Angels, but they have since faded into the background. They hang around (literally) on the sides of the tank (usually the back) or the Echinodorus leaves and stems, and don't move too much. Hopefully they will keep the algal growth in check (not that I have a lot of algae, thanks, I'm sure, to my plant population). I'm a little more concerned about keeping them fed. I suspect that they will be ok, even if the algal growth is limited - I'm guessing they can eat the plants, if nothing else. Still, I have decided to try feeding them some "parboiled" spinach. The websites I looked at suggested using "plant clips" (which apparently clip onto the side of the tank) to hold the spinach/zucchini/brussel sprouts, but I just tucked the spinach leaves into the gravel. I added the spinach this morning, and so far there has been very little interest from anyone - two of the platies are paying some attention to the leaves, but the Otocinclus have not made it anywhere near the bottom of the tank. Maybe I really do need some sort of a "plant clip", maybe the Otocinclus won't venture onto the bottom of the tank. We'll see, I suppose.
The other new additions are a very different story. Two Macropodus (hopefully a male and a female) have impacted just about every aspect of life in the tank - among other things, bumping the male fighter off his post as "top dog" in the tank. Although they have a reputation for aggression, so far I have been lucky - they have stared down the fighters and chased the platies a little, but overall nothing too serious. On the other hand, the male is harassing the female a bit much...still, there's enough cover for there to get some peace, hopefully. She doesn't look terribly happy overall though.
The presence of other anabantids have definitely affected the fighters. Initially the male got a lot paler, and the female a lot redder. Since then, he has recovered a lot of his colour, and she has lost some of hers, but their behaviour has definitely changed.
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