Suddenly the low survival rate of baby cichlids in aquaria – despite all my efforts to pile up small rocks to provide plenty of crevices for them – makes terrible, terrible sense.
You might be able to see, in the previous post, that the babies are in a separate container, hanging over the edge of the main tank. There’s about two inches of “overlap” where the adults can see the babies, and vice versa.
The fry don’t know the difference between mom’s mouth (safety) and all the other fishes’ mouths (DANGER). They’re doing this really interesting mobbing behavior against the wall of the enclosure every time an adult fish comes face-to-face with them. No matter which fish it is. I tried to snap a pic, but the adults are very interested in whatever I’m doing if I move the camera up, so it breaks the moment. Think chum ball, only with tiny itsy bitsy fish all facing the same direction. Desperately trying to swim into the mouth of a hungry adult.
I presume the mouthbrooding cichlids survive in the wild by having a heck of a lot more space in Lake Malawi than they’ve got in my aquarium, where the mom can wander away from the school and let the kids out for a bit when she’s alone. (Saulosi school in the wild, I am informed. If anybody’s studied their natural breeding behavior in depth, I haven’t heard of it.) Perhaps there’s some point in development at which the instinct to “dive for adult’s mouth” is switched to “swim like hell in the other direction” and stripping them before she naturally left them to their own devices short-circuited that. The “overstocked” conditions mbuna are kept in to reduce aggression means mom doesn’t really have any way to “get away” from the other fish, even though the holding females do become more aggressive than usual. The rusty fry from my currently holding rusty female are just gonna have to take their chances in the main tank though – that species isn’t one I’m terribly interested in breeding. Also it’ll be interesting to see if the one fry I left with the saulosi mom will do well – she looks like she’s still holding it.