Randall's Goby

[Instigate]

Can you keep them as pairs? Some places say they can be aggressive toward conspecifics but other places say they will often share their burrows with other types of gobies. I realize not all fish of the same species will act exactly the same and there are always exceptions. But what is most likely?

How can you identify sex? Some sources say the females don't have the eye spot on their first dorsal fin. Others say you can't identify sex by looks. So what's the deal?

Some photos I found online:

The goby on the right doesn't have it's first dorsal extended but if you look close it looks like it might be missing the eye spot.

These both have the eye spot but one does look subtlety different than the other. Maybe it's just a smaller fish than the other. Idk

I have also noticed that some of them have differently shaped first dorsal fins.
First dorsal fin goes forward:

First dorsal fin is more vertical:

 

[GoldeneyeRet]

I've always had these in my tank. I have never seen them aggressive to anyone, including other randalls. My current pair shares a cave with 2 rose gobies and a firefush.

I don't know how to distinguish male and fenale.

Great fish!

 

[eatbreakfast]

I haven't had problems with them behaving aggressively.

If there are multiples in a tank at an LFS, two will usually form a pr.

 

[Instigate]

I've always had these in my tank. I have never seen them aggressive to anyone, including other randalls. My current pair shares a cave with 2 rose gobies and a firefush.

I don't know how to distinguish male and fenale.

Great fish!

I haven't had problems with them behaving aggressively.

If there are multiples in a tank at an LFS, two will usually form a pr.

Nice. Two it is!