Cory Catfish gone missing

[ashlyn_8]

I currently have a 20 gallon tank with 8 Cory catfish and 1 beta fish. 5 of those catfish have been recently added, but the other 3 have been in the tank for around 4 months with perfect harmony with my beta. A couple days ago I noticed one of the catfish started to get a little pale, but I decided to just continue to watch if he was eating or getting worse over the next days. Today I couldn’t find him, and quickly noticed there were only 7 catfish in the tank. Took all of the decorations and plants out, checked the filter and heater, checked to see if he jumped out, and combed through all of the substrate — no dead catfish in sight. At this point I’m hoping that the Cory died and that all of the other fish ate the remains since that will be a much better alternative than a giant ammonia spike because of a dead fish stuck in the tank. Is it likely that the other fish ate the Cory, and if not, what should I do to make sure there isn’t an ammonia spike?

Checked the water conditions, and nitrate and nitrite levels are 0

 

[StripySnailGirl04]

First, test for ammonia for the next few days. If there is any ammonia above 0, then do a water change of around 50%. Many of my fish when they were pale died so that may have happened to yours. I think that the Betta may have eaten the Cory, I don't think the Cories would be interested in eating something of their own species.

 

[itiwhetu]

Bettas are surface feeders; their mouths face upwards. So, the other Cory's are most likely to have finished off their mate. Are you sure it didn't jump out, Cory's have a habit of doing that? These fish are armored catfish and don't decompose quickly.