Questions about Zoa eating Nudibranchs

[ichthyogeek]

I keep seeing pictures of pretty nudibranchs that eat zoanthids online, and figure that the people who avoid them the most probably know them the most! Ergo, questions:

How quickly does it take for zoanthid eating nudibranchs to munch their way through a colony? Is it a colony of nudibranchs, or typically just one? Do they only eat the tentacles? The polyps? The mat that Zoas/Palys grow on?

Does the variety of zoa eating nudi depend based off of the type of zoanthid that they come in on? Ex. are there nudibranchs that only eat Rastas, or ones that only eat Mohawks?

Will nudibranchs change color/pattern/texture based off of diet (i.e. turn green if they eat texas trash polyps, red if they eat red polyps, etc.)?

Will Zoa eating nudibranchs munch on all zoanthids? Or are there some that seem utterly inpalatable?

Are there any nudibranchs that get super big? Or are they all mostly very tiny?

 

[vetteguy53081]

They make a diet based on zoas and generally come in as hitchhikers. Zoa Eating Nudibranchs are a type of aeolid nudibranch which are known to feed on coral also and lay eggs in a circular pattern so you want to look out for eggs also. Dipping generally kills them so dip all zoas when you get them

 

[Oscar47f]

+1 from the guy above, adding on... they can and will eat whole colonies if given enough time, in my experience they’re slow eaters, they do change to the color of the zoanthid they’re eating this makes them blend in and not be noticed... if you have one there’s likely to be more, the spiral egg clusters they lay, those are hard to get rid of so if you see them put that coral in quarintine and dip regularly so that as the eggs hatch the dip kills them before they reproduce again, or you can try drying with a paper towel and scraping the eggs off... there are so many nudibranchs some are big some are small, some are non coral eaters and are helpful like the berghia nudibranch that eats Aiptasia and some are decorative like the lettuce nudi....

 

[najer]

All good advice above posts, I lost hundreds of zoas to them but they never touched palys ime.

 

[Palegic]

I got a couple as hitchhikers in my old tank. I noticed by the zoa's were shrinking and closing up due to irritation in large groups at a time. The nudis were well camouflaged and small so they were almost impossible to see. I wound up picking them off with some extra long precision tweezers. Luckily the eggs if there were any did not propagate.

 

[danschoenherr]

Good info above....
In my experience, they rarely ate the larger polyp zoas and palys. They do turn the color of the zoas that they are eating.
The best way to erradicate them, besides using a wrasse, was to search the tank when the lights are going down and are bluest, and use a magnifying glass to locate them. Once located, I usesd a turkey baster to suck them out, That, combined with a wrasse, was enough to clear my 50g frag tank in a week with only minor losses. The key is finding them early before they have a chance to multiply.