[Betta132]

How good are leopard ctenopomas at catching small, fast fish like mosquitofish? An attempted pond isn't working out so well, so I'm trying to find new places to put the mosquitofish, and I need a contingency plan in case I have a mean batch that can't go with my other fish.

Edit: The tank doesn't have too much cover. It's mostly leaf litter and some sticks, just enough to keep him feeling confident. I'm considering this because I had to put the mosquitofish into this tank before I got the leaf out (they were going to jump out of their holding thing and I knew it wouldn't take long to catch the leaf) and the leaf tried to catch them but totally failed. They'd see him coming and putter away. He's only a baby, though, a bit over 2" long. He could swallow the mosquitos if he could catch them, he just didn't catch them. Could this continue without stressing the mosquitos to death? There's a good bit of tannins and stirred-up clay (experimental mixed substrate + cories) in the water, so they wouldn't be constantly in sight of their predator.

 

[WaterLife]

These guys commented on a thread of mine and seem to have good experience with Ctenopomas. They should be able to share their thoughts.
I would think with them being ambush predators, they would catch prey more often with more plant/leaf litter cover to ambush from. Still might take him awhile to completely wipe them out though.
@jaliberti @frog111 @Mr. Limpet

 

[frog111]

I can't speak to how well they would do in a tank with less cover. My 55 is heavily planted, with Vallisenria, dwarf sag, Hygro, anubias, pogostemon quadrifolius, and who knows what else. But it is an overgrown, naturalistic jungle with lots of cover. I have about 12 swordtails, with 3 males and 9 females, and that population has been stable at athat number ever since I got the leaf fish. Before that, I had started with a trio of swords, and had a blue ram in place for population control. The ram clearly helped, but didn't catch every fry. The leaf fish does.

But observing the leaf fish hunting, it was strictly a wait and ambush approach. He never chased anything down.

 

[jaliberti]

How good are leopard ctenopomas at catching small, fast fish like mosquitofish? ... Could this continue without stressing the mosquitos to death? There's a good bit of tannins and stirred-up clay (experimental mixed substrate + cories) in the water ...

... I would think with them being ambush predators, they would catch prey more often with more plant/leaf litter cover to ambush from ...

... But observing the leaf fish hunting, it was strictly a wait and ambush approach. He never chased anything down.

Ctenopoma would not be efficient at all in catching small, fast fish like mosquitofish. Gambusia are the terrors of the aquatic world, just ask or Aussie members. Gambusia getting stressed to death by Ctenopoma? Never. More likely the other way around, they may very well gang up and shred the larger fish piranha-style. See this vid of them shredding a frog to the bone youtube.com/watch?v=TEUHVBvyD48 1:15-1:45 even if no comprendéis español the vid is still worth watching.

Having "a good bit of tannins and stirred-up clay (experimental mixed substrate + cories) in the water" sounds odd. Tannins are acidic, clay is alkaline. In which direction are you trying to go? Also note that Ctenopoma thrive in acidic water whereas Gambusia thrive in alkaline.

WaterLife & frog111 are correct, they're ambush predators, need cover to ambush from, it's strictly a wait and ambush approach, no chasing. Labyrinths, including Ctenopoma, by evolutionary design are neither strong nor fast swimmers.

 

[Betta132]

OK, good to know. I'll probably throw some ghost shrimp now and then to distract him, he got very enthusiastic about those last time I tossed them in. Not sure if he ever actually got any.

Sheesh, those things are vicious. It's a small frog, though, and small frogs have very delicate skin. Probably wasn't too difficult once they decided that they wanted to eat the frog.

The tannins are a consequence of the leaf litter, and there's a couple handfuls of clay mixed into the sand in an attempt to make it more plant-friendly. Evidently I didn't rinse the clay quite well enough, as the cories keep stirring up more dust. The water's right about neutral, the leaffish is captive-bred and therefore used to a wider variety of water parameters (evidenced by the fact that Petsmart was able to keep them alive), and the gambusia are gambusia. The combined visual effect of the tannins and clay is less-than-clear water, about like what you see in most ponds, though I'm working on filtering all the dust out.

I caught the leaf by hand so he wouldn't get tangled in a net, and much to my surprise, he started croaking when he was out of the water. Sounded like a very quiet version of those wooden frogs that make croaking sounds when you rub their backs with a stick. I did not know they could do that, and he made a grinding sort of vibration in the process, which was very weird. Comparable to picking up a caterpillar and having it squeak at you- which happens, tomato hornworms squeak when upset.

Edit: He's trying to catch them, but he sucks at this. They don't really seem to care, either, they kinda just dart off and then go "eh".

Another edit: Yeah, he really sucks at this. He gave up.

 

[Betta132]

Evidently leopard ctenopomas are, in fact, compatible with fast fish that they could technically swallow. He's given up entirely and doesn't even try to get at them. This is useful knowledge.

 

[WaterLife]

What about at night though when the fast fish are sleeping? They might be easy targets then. If they happen to become aware, I would think the stress of trying to sleep at night with one eye open might gradually wear on them. So I'm not so sure a community tank with the ctenopoma and smaller fish is best idea (at least not paradise for the little fish).

But thanks for reporting!

 

[Betta132]

The mosquitos sleep at the top, the leopard tucks under the leaves at night. And they definitely don't care about him right now, they just ignore him, even when he's out in open water and clearly visible. Either they're too dumb to care or they don't think he's a threat.
They may not be permanent, anyway, I was breaking down an attempted pond and had to put them elsewhere. My choices were: tank full of tiny fish that the mosquitos would tear apart, tank containing a very fast, very enthusiastic warmouth sunfish, betta tank, or tank with leopard.

 

[Betta132]

One mosquitofish is missing, but it was small and slow and not very healthy-looking anyway. I'm not even certain that the leopard got it, it could have died. All the healthy-looking mosquitos are perfectly fine, and they don't seem stressed out by the leopard, probably because he ignores them.

 

[jackmerius27]

My ctenopoma killed 5 cardinal tetras and 4 threadfin rainbows.

 

[Nordic]

In nature, things like cardinals often swim in line of sight of their predators. I mean like 1 or 2 feet away, and hardly flinch.
Predators have a way of going for the easy prey, sick fish hanging isolated at the bottom etc...

 

[Betta132]

My mosquitos are wild-caught from a fairly predator-heavy area, and they take steps to avoid any larger fish in the tank, even the ones that won't eat them.
Cardinal tetras seem to rely on their schools to stay safe, and captive-bred ones have probably lost some of their instincts by now.
The threadfins seem a bit on the larger end for a leopard to eat. Are you sure he was the culprit?

 

[AlexAlex]

I have Ctenopoma and yes, they're not good at catching mosquito fish at all. Any recommendations from guys who know more than me would be welcomed. I'm relatively new to this and recently I got my very first tank, so I'm looking for a piece of advice. I found great tips on wildlifechase.com but I'm open to other recommendations. My main issue is how do I control the mosquitofish. I have four sword tales, seven anubias, some assorted platy and I'm planning on getting more. Do you guys have any recommendations?