Added a second diamond gobby

Bluefalcon2017 · Oct 5, 2021

Good evening,

I have a 65gal tank. I have a diamond back gobby who does his thing. Today at the LFS I saw a baby diamond goby and thought it would be nice to have a second.
I asked the fish guy if there is any issues with having two gobbys in a single tank and he said no.
Well, I got home, and my big gobby became aggressive and tried to eat the baby gobby.
for now, the baby gobby is in a breeder float tank, injured.
what should I do? I even put the baby gobby on the opposite side when I put him in to avoid such altercation.

Arthacker87 · Oct 5, 2021

Most the time you have to add same kind of fish at the same time and even then eventually they become aggressive. Unless different sex.

jdiefenbaugh · Oct 5, 2021

If you're trying to pair those fish, generally you need them quite a bit different in size from each other. Even then, it may not work. A lot of fish won't tolerate conspecifics, especially in a tank that small. An acclimation box with sand would have been a good place to start.

AjDavis74 · Oct 6, 2021

Bluefalcon2017 said:
Good evening,

I have a 65gal tank. I have a diamond back gobby who does his thing. Today at the LFS I saw a baby diamond goby and thought it would be nice to have a second.
I asked the fish guy if there is any issues with having two gobbys in a single tank and he said no.
Well, I got home, and my big gobby became aggressive and tried to eat the baby gobby.
for now, the baby gobby is in a breeder float tank, injured.
what should I do? I even put the baby gobby on the opposite side when I put him in to avoid such altercation.

Our 2 year old diamond goby does so much sand sifting and home building ( I swear he has a couple condos under the live rock) he often clouds up the 150 gallon. So when I wanted to get him a girlfriend my husband said no lol. We got a lil yellow watchman goby instead. The diamond hasn't been aggressive at all. Other than the occasional "look how big my mouth is" standoff. Now when he moves to his other condos at the other end of the tank lil yellow house sits his other hole.