On the wrasse you may be better off asking your Sixline - they can be great with others or real jerks.
If you want to risk it, I agree to stick with another active wrasse like a mystery or maybe a Yellow- or Melanurus wrasse.
On the flip side, you may want to give the Sixline some time to grow out and see how he blends in before adding others. 90 is not a huge tank for habitat - the sixline (as well as all the other wrasses suggested) cruises constantly hunting for food and would very much appreciate all that space to himself - at least all to himself in terms of other wrasses.
If your Goby has a shrimp or otherwise tends to stay in one spot, then you might get away with a second goby, but they're kown for not getting along with similar gobies, so it's a risk. (Persoanlly unless the tank was set up specifically for them (some people a true fans!) I don't use sand sifters like that anyway and for your case they'll be competing for a lot of the same food sources in the tank as your Sixline.) If your goby doesn't yet have a shrimp, I'd think about that as a great alternative to a sand sifting goby.
I believe that either addition you suggested would also increase your risk of someone becomming a jumper - both are famous for that. Might still jump if they are solo, but with another in there to possibly fight with, it is more likely someone's fight/flight response will be triggered.
Good luck and let us know what you decide to do!
-Matt
I hate to say it, but that serpent star probably isn't trying to make friends - he's just waiting to grow up a little more. They are wicked ambush predators when the prey size is right and they are hungry. I wouldn't keep them with the fish you have. Can't be trusted.
Maybe I've just been lucky, but I've had both of the for a couple of years. I have accused the Tiger Serpent of eating my hermits and snails though.
Have a bucket of tank water on standby as you may accidentally catch another fish first.
You can put more than one goby in your tank I have 4 in my 120 gl and they don't bury my corals that are on bottom , of tank , but a 6 line wrasse will totally beat up the goby there extremely aggressiveOn the wrasse you may be better off asking your Sixline - they can be great with others or real jerks.
If you want to risk it, I agree to stick with another active wrasse like a mystery or maybe a Yellow- or Melanurus wrasse.
On the flip side, you may want to give the Sixline some time to grow out and see how he blends in before adding others. 90 is not a huge tank for habitat - the sixline (as well as all the other wrasses suggested) cruises constantly hunting for food and would very much appreciate all that space to himself - at least all to himself in terms of other wrasses.
If your Goby has a shrimp or otherwise tends to stay in one spot, then you might get away with a second goby, but they're kown for not getting along with similar gobies, so it's a risk. (Persoanlly unless the tank was set up specifically for them (some people a true fans!) I don't use sand sifters like that anyway and for your case they'll be competing for a lot of the same food sources in the tank as your Sixline.) If your goby doesn't yet have a shrimp, I'd think about that as a great alternative to a sand sifting goby.
I believe that either addition you suggested would also increase your risk of someone becomming a jumper - both are famous for that. Might still jump if they are solo, but with another in there to possibly fight with, it is more likely someone's fight/flight response will be triggered.
Good luck and let us know what you decide to do!
-Matt
I also have a six line in a 90 gallon, but after all my research, I made sure he was the last fist I was going to add before getting him. From what I have read about them, the term “wrassehole “ was derived with them in mind. I love mine, but I would never put another wrasse in there for sure, and if was to add ANY more fish, I would probably rearrange the rock work, so it was in effect a new tank for all. Sounds crazy I know, but the six line can be a real bully.
