A third wheeling Cory????

[DamaFish]

I have 4 fish, 3 cory and a goldfish. My concern here is about the cories, I have had them for a year or more I want to say and at the beginning all three would school together and say a week later its only two that stick together and obvi the other is lonely in a corner or just plain on the other side of the tank. Before I didn't really think much of it but I moved them to a new tank a day ago and day one they were all together, even playing and feeding together (ALL THREE). The tank they were in before had little hiding spaces and this new one has faux plants, a tilted treasure chest and a log for them to hide in. I come home and the two are paired up again and the one has been in the log for about 2 hours. he was in there already when I got home. I fed them and hes still hiding. I am wondering if I should even out their numbers and get another lil guy. I would hate to get another one and then that one stick with the two. None of the fish are sick and the water is fine. as I type this the pair swim and feed together.
What do you guys think??

and i forgot to mention the cories are Emerald Cory catfish
the pair is named Willy and Vaz
the lil loner is Mike
and the goldfish is Tiger.

the pictures are of Willy and Vaz and I cant get a clear picture into the log of Mike and of course the attention hogger wanted to be in the picture of the log too haha

 

[Colin_T]

Corydoras and Brochis need to be kept in groups of at least 6 or more and preferably 10 or more. However, before you add more fish, is the new tank cycled?

If the fish is not eating that is a concern.

The catfish on the left (top) in the second picture looks like a bronze Corydoras and not a Brochis.

If the fish is healthy and the tank is big enough and has a cycled filter on it, then add some more but if one isn't eating then monitor them for a few weeks and if they are ok, then get some more.

If possible, quarantine all new fish for a month before adding them to the main tank.

 

[NickAu]

The tank is too small for a gold fish.

 

[Jeremy180]

If one of the cories is a misidentified bronze Cory that was mistaken for an emerald, this would explain the "third Wheel" behavior, as cories generally tend to only school with their own species, unless out of desperation when feeling particularly insecure, like for example, arriving at a new tank, or having the decor rearranged.

The biggest issue here is space.

While these fish are potentially compatible, a big enough tank to house a full grown goldfish, plus the recommended minimum six each of bronze Cory and emerald Cory, would be at bare minimum a 55 gallon, preferably 75 gallon or more.

Goldfish are best kept in groups, too, but can learn to tolerate being kept singly, providing they have a lot of cover, if (likely) you don't have the room for the 30 or so gallons each require when fully grown.
Not an ideal situation, but much better than trying to keep 5 goldfish in a 75 gallon

With proper care, it is not unheard of for all the species you have to live over 20 years.

 

[DamaFish]

I have come to the conclusion that Mike is just shy because he does hang out with the other two a bit. theyve started to eat together more often and then he likes to rest in the log alone. His eating habits are fine and all the fish in the tank are healthy.

 

[DamaFish]

i am very aware the tank is WAY to small for my goldy but until february I have no choice but to keep him there.

 

[DamaFish]

In the pictures it may look like a bronze cory but I am certain all three are emerald. they all have that nice green shiny tint and if in the right angle of light they look like they have green armour on haha

 

[Jeremy180]

OK, well it is possible that three cories isn't enough for them to school normally but a bigger tank might be a higher priority in this case than getting more cories