I recently obtained five crocodile toothpick fish from my favorite LFS. The guy working there was actually their former owner, and he'd apparently been keeping them in a 2.5g with two lampeye killifish and a male betta. He'd been feeding mysis to the betta, but the other fish weren't getting fed- they were just eating random bugs.
The toothpickies are in my 29 Biocube, which is moderately planted and well on its way to being heavily planted. They're sharing it with various small schooling fish, most notable being a few ruby tetras who don't really show up at feeding time and are probably eating bugs. I haven't seen the little things since I put them in, but I'm not worried... The guy who used to own them said that he didn't see them often, and that was in a tiny tank. In fact, he thought he had only three until he took down the tank and found two more.
They really do look like crocodiles crossed with toothpicks.
Note: These are not the toothpick fish from the Amazon, the nasty parasitic ones that were in the news a while back. Those are catfish, and not a species that's kept in aquariums due to being parasitic. These are a harmless species, somewhat similar to sticklebacks, and they basically act like stubby pipefish. They hover around, eat small bugs (won't take prepared foods), and are totally harmless to anything short of near-microscopic bugs.
EDIT: CARE THINGY. This is based off of my research, as well as observation.
Indostomus crocodilus or paradoxus. Care is exactly the same, as far as the world knows. Crocs have black stripes on the fins of the males, paradoxus do not.
Crocodile toothpick fish, paradox fish, armored stickleback, and freshwater pipefish are some of their names.
They are more closely related to sticklebacks than pipefish, but they act like pipefish.
Maximum size: 3-4 cm or so, males maybe a bit smaller. Very small, very thin, low bio-load.
Food: Very small things. Could possibly be weaned onto Cyclop-Eeze, but can most likely feed themselves from bugs in plants in a well-established tank. Micro-worms are a suggested food that I think would work well.
Compatibility: Not particularly afraid of active fish like emerald eye rasboras, don't care about others. Probably safe with anything that won't eat them. Will also be safe with any cherry shrimp past newborn stage- they're very tiny and have small mouths.
According to the former owner, they prefer to have others of their kind around, like ottos. That's why I got all five, so none would be left with too few companions. From what I've seen, the males may be mildly territorial when it comes to nice spots.
Breeding: Not sure. Egg-layers, I think, as males do not have gonopodiums. Probably best to keep them in a heavily planted tank and just let them do their thing. The only breeding instance I've read about was basically a bunch of them in a planted tank on their own, so it's somewhat possible they can change gender.
Gender determination: Male crocs' will have black stripes on their fins. Females are slightly larger and fatter in both species.
Notes:
They hover around a lot and use any nearby object as 'down', so they can be seen swimming vertically. They're very slow, methodical feeders that kind of just drift around... I'd say they need special feeding, except that they feed themselves.
Do not keep in a non-planted tank. Also, probably best to give them some oak leaves in hopes of growing bugs.
You will NOT see them often. They aren't skittish, just kind of reclusive. They prefer to hang around in the background and will only sometimes drift out to look around.
They are simply not afraid of most fish. I watched one sit in the middle of an emerald rasbora swarm for a few minutes, and it didn't seem to care that it was surrounded by streaks of chaos that were bigger than it.
They're also very curious about shrimp, but they aren't able to eat an adult one or even bother it very much.
Sort of rare in the hobby, as far as I'm aware. Grab them if they turn up.
They like to swim with their back pressed to the underside of a stick. Makes them look like a piece of bark.
They should NOT be kept without wood or sticks or similar. It's their favorite place to be, as far as I can tell.
They can actually move very fast when startled, despite their tiny fins.
The tail is mostly used for steering, but the fin can be used for one strong push if they need to dart to cover.
They have a pair of tiny fins in their stomach area that they often rest on.
Males tend to become more active if they see each other. Not sure why. It doesn't look aggressive...
Males do not have gonopodiums, as far as I can see, so I doubt they're livebearers.
They don't seem to school or anything. Their habit of being near each other is likely due simply to them liking certain spots- such as all hanging out under driftwood.
They aren't a huge fan of bright lights but will venture out into the open now and then to investigate. A mild amount of tannins should help make them come out a bit more; I'd suggest a few oak leaves.
They're curious and seem intelligent- sort of remind me of bettas in some ways.
Upon noticing somebody watching them, they often pause to stare at their watcher for a minute or two.
They like to sit still and pretend to be twigs.
They aren't particularly bothered by other fish. They do avoid large clumps of activity, but they don't look scared... They just slowly circumvent the overly active area, eyes on the activity, and proceed on their way once they get past the chaos.
They don't like being approached from behind by larger fish and will quickly swim a few inches away before continuing.
Oddly, being run into by an emerald eye rasbora (fast, about as long as the 'crocs but three times thicker) doesn't bother them beyond making them race away a few inches and put something between them and the offender- at least, from what I saw. Little guy didn't even look upset, just kind of annoyed.
The toothpickies are in my 29 Biocube, which is moderately planted and well on its way to being heavily planted. They're sharing it with various small schooling fish, most notable being a few ruby tetras who don't really show up at feeding time and are probably eating bugs. I haven't seen the little things since I put them in, but I'm not worried... The guy who used to own them said that he didn't see them often, and that was in a tiny tank. In fact, he thought he had only three until he took down the tank and found two more.
They really do look like crocodiles crossed with toothpicks.
Note: These are not the toothpick fish from the Amazon, the nasty parasitic ones that were in the news a while back. Those are catfish, and not a species that's kept in aquariums due to being parasitic. These are a harmless species, somewhat similar to sticklebacks, and they basically act like stubby pipefish. They hover around, eat small bugs (won't take prepared foods), and are totally harmless to anything short of near-microscopic bugs.
EDIT: CARE THINGY. This is based off of my research, as well as observation.
Indostomus crocodilus or paradoxus. Care is exactly the same, as far as the world knows. Crocs have black stripes on the fins of the males, paradoxus do not.
Crocodile toothpick fish, paradox fish, armored stickleback, and freshwater pipefish are some of their names.
They are more closely related to sticklebacks than pipefish, but they act like pipefish.
Maximum size: 3-4 cm or so, males maybe a bit smaller. Very small, very thin, low bio-load.
Food: Very small things. Could possibly be weaned onto Cyclop-Eeze, but can most likely feed themselves from bugs in plants in a well-established tank. Micro-worms are a suggested food that I think would work well.
Compatibility: Not particularly afraid of active fish like emerald eye rasboras, don't care about others. Probably safe with anything that won't eat them. Will also be safe with any cherry shrimp past newborn stage- they're very tiny and have small mouths.
According to the former owner, they prefer to have others of their kind around, like ottos. That's why I got all five, so none would be left with too few companions. From what I've seen, the males may be mildly territorial when it comes to nice spots.
Breeding: Not sure. Egg-layers, I think, as males do not have gonopodiums. Probably best to keep them in a heavily planted tank and just let them do their thing. The only breeding instance I've read about was basically a bunch of them in a planted tank on their own, so it's somewhat possible they can change gender.
Gender determination: Male crocs' will have black stripes on their fins. Females are slightly larger and fatter in both species.
Notes:
They hover around a lot and use any nearby object as 'down', so they can be seen swimming vertically. They're very slow, methodical feeders that kind of just drift around... I'd say they need special feeding, except that they feed themselves.
Do not keep in a non-planted tank. Also, probably best to give them some oak leaves in hopes of growing bugs.
You will NOT see them often. They aren't skittish, just kind of reclusive. They prefer to hang around in the background and will only sometimes drift out to look around.
They are simply not afraid of most fish. I watched one sit in the middle of an emerald rasbora swarm for a few minutes, and it didn't seem to care that it was surrounded by streaks of chaos that were bigger than it.
They're also very curious about shrimp, but they aren't able to eat an adult one or even bother it very much.
Sort of rare in the hobby, as far as I'm aware. Grab them if they turn up.
They like to swim with their back pressed to the underside of a stick. Makes them look like a piece of bark.
They should NOT be kept without wood or sticks or similar. It's their favorite place to be, as far as I can tell.
They can actually move very fast when startled, despite their tiny fins.
The tail is mostly used for steering, but the fin can be used for one strong push if they need to dart to cover.
They have a pair of tiny fins in their stomach area that they often rest on.
Males tend to become more active if they see each other. Not sure why. It doesn't look aggressive...
Males do not have gonopodiums, as far as I can see, so I doubt they're livebearers.
They don't seem to school or anything. Their habit of being near each other is likely due simply to them liking certain spots- such as all hanging out under driftwood.
They aren't a huge fan of bright lights but will venture out into the open now and then to investigate. A mild amount of tannins should help make them come out a bit more; I'd suggest a few oak leaves.
They're curious and seem intelligent- sort of remind me of bettas in some ways.
Upon noticing somebody watching them, they often pause to stare at their watcher for a minute or two.
They like to sit still and pretend to be twigs.
They aren't particularly bothered by other fish. They do avoid large clumps of activity, but they don't look scared... They just slowly circumvent the overly active area, eyes on the activity, and proceed on their way once they get past the chaos.
They don't like being approached from behind by larger fish and will quickly swim a few inches away before continuing.
Oddly, being run into by an emerald eye rasbora (fast, about as long as the 'crocs but three times thicker) doesn't bother them beyond making them race away a few inches and put something between them and the offender- at least, from what I saw. Little guy didn't even look upset, just kind of annoyed.