can yellow and blue assessors coexist?

[flame9x]

I'm curious about the one male per tank rule, but what if we have one of each species? Are they distinct enough to coexist, or is it not a good idea? I've been searching for information on this, but I haven't found much so far.

Thanks

[brixo]

I had a similar issue, I've got a yellow assessor and was thinking of adding a blue one, but I was told not to due to the yellow one already being established in the tank. I'm not sure how they'd interact if introduced at the same time, it's a bit of a gamble. I think you'd just have to try it and see what happens, to be honest. Sorry, not much help, I'm afraid.

[flame9x]

I reached out to the Wetwebmedia.com team, my first time asking them for help. Now I just have to wait and see what they have to say.

[rustyfox9]

I'm not sure if this will be of any use, but I thought I'd share it anyway. I was reading Reef Secrets by Alf Nilsen and Svein Fossa, and on page 85 they have a biotope suggestion for a Red Sea cave. They mention that the yellow assessor isn't actually from the Red Sea, but they include it because it likes to be upside down in caves. The tank they describe is 190 liters or 50 gallons, and they stock it with a mix of species, including an Orchid dottyback, a blue stripe dottyback, 15 yellow assessors, and 25 dancing shrimp - all added at the same time, I might add. The idea is that the shrimp will group on the roof of the cave, while the yellow assessors swim around with their bellies facing upwards. I remembered reading this somewhere and it just clicked into place. I'm assuming that since they were all added together, they should be okay with each other.

[flame9x]

Thanks for the info. I've come across a few instances where people have successfully kept them in schools, but those tanks were significantly larger than mine. My 29g just might be too small for that. I wasn't sure if having a similar body shape would be enough to make it work, or if the slight differences would cause issues. From what I can tell, the main difference is the color, but I could be wrong.

[fleeton]

I think that's a tough call, KJ. If you're dead set on trying it, I'd say your best bet is adding them at the same time. Letting one assessor get established in the tank first, then introducing another, is just asking for problems.

[flame9x]

I'm thinking of reversing my plan, getting the assessors before the clowns. Setting up two QT tanks to quarantine them individually, making sure they're healthy and eating well, then adding them to the DT at the same time. Problem is, I might not be able to find one or the other for a while, they seem to be seasonal. Guess I'll just have to try.

[flame9x]

Hi there, I've been a huge fan of WWM and I've always recommended it to others. I've finally got a question that's stumped me. I'm thinking of keeping a Yellow Assessor and a Blue Assessor together in my 30g tank. I know they're pugnacious if crowded, but I'm not looking to keep a shoal - just the two of them.

I've read that you can keep them in a larger tank with just one male, but I'm wondering if the two species are different enough to ignore each other. I've got a pretty established tank - it's been running for three months now, with about 25lbs of live rock and my current stock is two yasha gobies with a red banded pistol shrimp. I'm thinking of adding a couple of Picclyasso perculas later on.

My tank's been doing great since I set it up in mid-March, with the live rock curing in two weeks and my current fish added in May. I'd love to hear your thoughts on whether I can keep these two assessors together. Thanks for all your help and keep up the great work.

[felinxo]

Honestly, I'm not sure I'd take the risk in a tank your size. The blue assessor seems more aggressive than the yellow one, and as they grow, I think you'll likely run into problems.

[pikabird]

I'd advise caution, to be honest. The blue assessor tends to be more aggressive than its yellow counterpart, and as they mature, I think it's likely you'll encounter issues in a tank of your size.