fish eating other fish's poop... stupid fish, smart fish, or is this my fault???

[Magnum Man]

I've heard of baby fish eating their parents poop, on some fish, as it helps develop digestive bacteria... but I don't typically see this in my mixed cichlid tank... I've seen them taste it, and spit it back out, normally... but this morning I witnessed them treating another fishes poop, like it was food... caffeine thoughts made me wonder if one of the foods I fed yesterday, in the mix, was more undigestible, and was still recognizable as food in the poop... if something in the food was too complex, or case hardened, and thus was undigestible???
one of the mix of foods I fed yesterday was Hikari vibra bites, which I only add every couple weeks, otherwise, yesterday's mix was staples I use every couple days... I am feeding less ( I have a tendency to over feed ), but have never seen this previously... thoughts???

https://www.amazon.com/Hikari-HIKARI-Vibra-Bites-9-8oz/dp/B07KDGQHNW/ref=mp_s_a_1_15?crid=1TX7L1383J113&dib=eyJ2IjoiMSJ9.16kgHdEXO0LU4HKqicx4dV6s7_AdLLXIPY5NMt1XDx2QGaTZ6wMjDMHM2pUNwLGAhqvqqfAamPKe9VC5oeBilV8hs8BOQ0-zv827E3OsFx_P1HV1jNxWwjzWUidTPgraBUFS6Hp2aG9w6-dBjFrSdtAiReYfyaCuuz0SWaX98MSrpn956_0YvX48zHszBJYyBIpT1dvsAB4AliaU3ut-sg.hkNSiZs2MAVCPmOHqyWtrytVwTtQR9GfDm6QUGhTPlk&dib_tag=se&keywords=fish+food&qid=1740400475&sprefix=fish+foo%2Caps%2C205&sr=8-15

 

[GaryE]

A lot of our small fish are detritivores - eaters of detritus and mulm. Given that we have a wild range of intestines in our tanks - specialists in digesting plants, bugs, algae, biofilm, scales, eyes (yup, it's a thing), fry, snails - they digest differently. They'll get nutrition from general foods, but they can't all take in the same nutrients, and the leftovers can be interesting to others. There's even a Genus, Scatophagus, with 'scat' meaning poop.

I have read that one method of raising kissing gourmis in large numbers is to dump animal manure into the ponds. If one tries to kiss you, consider that.

I have seen things to ponder with my own morning coffees.

I had one undescribed Steatocranus (sp red eye in the hobby) that would pierce snail shells, and slurp the snails out. Then it would neatly stack the shells by the door of its cave. So the food may also have carried over to a breeding display, lek type thing. It was quite the molluscivore, and probably would have had a lot of undigested plant matter in its poop.

I've noticed in single species tanks, wastes accumulate more than in communities. I think that's partly because of feeding.