Little Red Nudies all over my back glass...

[stevenp]

I have been noticing these little red nudis in my tank and last night, upon further inspection, I noticed they appeard to be eating the small curly-q fan worms (Spirorbidae?) on the overflows of my aquarium.

I did a little research this morning and came up with this:
http://www.seaslugforum.net/display.cfm?id=2299

Anyone else have experience with these? Any comments?

Steve

 

[LeslieH]

Are you sure they're branchs and not flatworms? Take a look at the Hitchhikers slide show in this month's Reefkeeping Magazine for a couple images of red flatworms that commonly occur in tank. These will build up in numbers, deplete their food supply, then vanish.

 

[stevenp]

100% sure, they're nothing like a flatworm.

I think I got a good ID:

http://www.nudibranch.com.au/pages/8490a.htm

Steve

 

[dc]

I've never seen them. Generally they are all specialized feeders, eating only one thing. With luck it's not something you want in your tank.

Did a search and found this. Sounds like you are right on the ID.
http://slugsite.tierranet.com/news/anews20.pdf#search="Vayssierea caledonica"

 

[LeslieH]

Oh, now that's really interesting. I didn't know there was a nudibranch that preyed on spirorbid polychaetes. Next time I go collecting I'll have to look for them!

 

[stevenp]

I don't really care if they eat all the spirorbidae, but since the spiro' reproduce so rapidly I'm not sure if the nudi's will ever run out. I just hope they don't start eating featherdusters as well since they're pretty similar to the spiror'.

The way I see it is there are two possible ways I could have gotten them:

1) From someone in my club, or from a LFS.

2) I was recently in Melbourne where I picked up a couple weathered sea shell fragments off the beach. I threw them in the tank when I got home. I didn't think much of it since they weren't whole shells and had no place for 'stuff' to hide.

I think #1 is more likely esp. since Victoria is quite a ways south of Queensland, but who knows...

Steve