Randall's Assessor w/Royal Gramma?

[Deinonych]

I've noticed that LA/DD has started to get ORA captive-bred Randall's Assessors in stock recently. This is a fish that I have considered adding to my aquarium for a while now. I have an established Royal Gramma in the tank, but he is not territorial - in fact, he's kind of a sissy. He doesn't defend his territory from any of the other fish, and I've only seen him do the mouth gape thing once or twice.

I'm wondering if adding a Randall's Assessor will cause conflict, or if my tank has enough space for both to coexist? I have a good amount of rockwork, but the RG "owns" the lower portion of my larger rock formation with a number of tunnels and bolt holes that he has built over the last year. Thoughts?

The other inhabitants of my tank are as follows:

• Breeding pair of Ocellaris Clownfish
• One-spot Foxface
• Kole Tang
• Tailspot Blenny
• Blue Reef Chromis
• Firefish
• Blue Flasher Wrasse
• McCosker's Flasher Wrasse

 

[ThRoewer]

I find grammas to be very peaceful and rather submissive fish. I have 3 of them in one of my 10 gallon QTs. They formed their hierarchy with the strongest becoming male and growing to twice its original size and the smallest not growing much at all. But besides some chasing and comment fighting (pretend fighting) there were no injury fights.
They got even chased off by a much smaller baby marine betta I introduced much later - this goes kind of in line with you calling yours a "sissy".

I have never had an Assessor (though a group yellow ones is on my wish list) but from what I have seen of them in stores they seem to be very similar to grammas on one side and marine bettas on the other. I wouldn't think of them as aggressive, especially not against other species.

 

[Deinonych]

Thanks ThRoewer. An alternative I have considered is getting another RG (or a pair). Do you recommend a trio over a pair, or does it matter much? Would introducing another RG or two be challenging given the fact that my current RG has been in the tank for more than a year?

 

[ThRoewer]

I feel a trio or even a larger group is better, especially if adding to an established individual. It will spread aggression and the established one can't concentrate on hunting a single individual. Over time they will develop a hacking order and each will primarily just "discipline" the individual directly below him/her. My largest mostly chases the mid sized while largely ignoring the smallest. That one gets only chased away when he/she gets too ballsy during feedings. Often they are out together peacefully.
If you add more get small ones as your single one is likely a male by now.
As long as there are enough holes to hide it should be fine to add more as the established one can't be everywhere at the same time.

 

[bat21]

I've actually thought about this combo as well. I also have a gramma and would love to get a randall's assessor but I just assumed they are too similar and would not work. Does anyone have this combo in a tank under 75 gallons?