Danios eating each other

[Ken Sauer]

I am a fairly seasoned fish keeper. I just inherited a 3.5 gallon tank my daughter was using for her Betta fish (she upgraded to 10 gallons). I used it to quarantine 6 scissor tail rasboras and that worked out well. Today, I purchased 6 albino daneos and put them in the quarantine tank. I just checked on them and there are only 4 left (the top of the tank is secure). There was a well-eaten fish body at the bottom and the 4 that are left are going crazy. I don't know where the 6th fish went. I guess he was killed and eaten in entirety. I didn't know danios killed each other. Help.

 

[Circus]

They probably didn't kill each other. It is normal for fish to eat one of their dead fellows, but minnows don't tend to do more than fin nip.
What are the water conditions: ammonia, nitrite, nitrate? Did you keep the tank cycled, or set it up new?

 

[Bruce Leyland-Jones]

When you say 'albino danios', albino what danios?
As I'm sure you know, danio are very active fish and relatively tolerant of poor water, so going ape suggests there's something about the water they really don't like.

 

[Rocky998]

I am a fairly seasoned fish keeper. I just inherited a 3.5 gallon tank my daughter was using for her Betta fish (she upgraded to 10 gallons). I used it to quarantine 6 scissor tail rasboras and that worked out well. Today, I purchased 6 albino daneos and put them in the quarantine tank. I just checked on them and there are only 4 left (the top of the tank is secure). There was a well-eaten fish body at the bottom and the 4 that are left are going crazy I don't know where the 6th fish went. I guess he was killed and eaten in entirety. I didn't know danios killed each other. Help.

Ive never heard of this happening... But I guess there is a first for everything... Are all of them males? I only ask because almost all species are aggressive with males of their own species and maybe you did not get a good mix of females and males.


Also just a small side note: We all try to keep this a family friendly server and refrain from using any form of vulgar language. I am not a moderator but I am letting you know in advance so a mod doesnt have to

 

[Slaphppy7]

Is the 3.5G tank cycled?

If so, my guess is huge amount of stress from a group of highly active fish that are confined to an area that is much too small for them.

Most fish will scavenge on dead fish.

 

[Ch4rlie]

I second the query about if the quarantine tank was cycled or not.

Also a 3.5g tank is a tiny quarantine tank tbh, thats only 13.5 litres, too small for danios, be fine for quarantining short term for very small nano fish or single number of fish or shrimps really.

Might be the fact tank is very small that may have stressed said danios out and thus started nipping / bullying weaker or smaller tankmates which resulted in the death of danios, and all dead fish is fair game for being eaten as is full of protein and nutrients for all living tankmates.

 

[Rocky998]

Oops I thought the 10 was his quarantine... read it wrong