Possible fin rot + Emaciation/internal parasites?

[Kinokunya]

Hi guys I've noticed a split fin in one of my bichirs, and in the other tank, a very thin and unhappy CAE.

Please help identify if they are suffering from any diseases.
Thank you.

[seanskye]

That's a Golden Algae Eater (GAE), the CAE is dark greyish in colour. How long has the poor guy been in the tank? If he's new he's probably still adjusting. Try feeding him a few algae wafers (make sure he has some leftovers at least after the yamatos in your tank have run off with most of the wafers). Another reason could be because of the bigger GAE in the same tank. Sometimes they exhibit territorial behaviour and one usually wins when it comes to food. My 2 GAEs also grew at different rates even though I bought them at the same time at the same size. One is 5 inches long now while the other is 4 inches. However, my smaller GAE is still much fitter looking than the one in your picture.

[Kinokunya]

Hi Sean, sorry I'm used to saying CAE ever since I googled for them the first day haha. FYI it has been one of the 'pioneers' of the tank. Survivors of the tank cycle include my 4 guppies and 2 GAEs. Tetras, guppies, lampeyes came and up lorry. Tank has been running for like 3 months now.

Like you I bought 2 similar sized GAEs since day 1. The other (Gin) is vey fat and active. It likes to chase the thin one (Kira). Kira likes to hide a lot though I still see him passing off waste. Kira has faint black smudges on his body.

Newest tankmates introduced 3-4 weeks ago include 5 cherrys and 3 yamato shrimps. Yamatos and cherries will take the shirakura food, ignoring the algae wafers (meant for GAEs) that I've thrown down. Gin has taken a liking to Shirakura shrimp food too.

[seanskye]

Haha I think our situations are quite similar, but your other GAE seems to be more dominant in this case. I've seen my bigger GAE bully the smaller one quite often (it also fights with the CAEs in my tank) but it got better when I added some hideouts (coconut shells, driftwood with big holes, etc) in my tank. If you want them both in the same tank you could add more hiding places to reduce their stress levels (and hence agression?).