Which are pests and why are they pests??

[ctniners]

Hi guys,
I have a question about pests…..I read other posts where people complain about nudibranches…..

I have a fairly new set up 4 months old….I have all hard corals and some zoas, but I have noticed a bunch of nudibranches (different colors)…..all my frags and zoas seem ok, how do I know which nudibranches are bad?....I hate to kill anything in my tank just by generalizing nudibranches as pests.

Also I have seen some little sea stars that don’t have the usual arm lengths, like 3 arms are the same size and one is half the size, I heard these are also pests…..but what do they do to be called pests.

Thank you for input.

 

[Elysia]

This is sort of like "what is a weed?" "A plant that one hasn't found a use for yet."

Most everything that is considered a pest falls into one of two categories A) it breeds prolifically/spreads exponentially (often to the detriment of other animals in a captive environment or B) it feeds on some desireable animals that you want (and probably paid a lot of money for.)

If you post photographs of your nudibranchs, someone will likely be able to ID them as to whether or not they are nudis (or some other kind of seaslug) and whether or not you should be concerned. You can go to http://www.seaslugforum.com and browse through some of the species there, but it is sometimes difficult to ID a slug without knowning where to start the search.

As for the stars, if they are "classic" stars (not mini or micro brittles), some have had experience w/ such stars preying on coral, but many others have not had any problems with them (may be that there are multiple types and only some are coral predators, may be that only some are inclined to eat coral.)

 

[perenes]

will brittles really eat corals?

 

[Elysia]

<a href=showthread.php?s=&postid=14775349#post14775349 target=_blank>Originally posted</a> by perenes
will brittles really eat corals?

Not that I know of. Reread what was posted.

 

[flyyyguy]

I believe they were referring to asterinas with the different length of arms. Most of which are harmless grazers, some of which are definitely predatory. The only real way to tell the good ones from the bad ones is by where they hang out. I have encountered both sps eating ones and zoa eating ones so I do not discriminate the good from the bad. If I see them they get released into the wild. I live in a high desert.

 

[LeslieH]

The little asymmetrical sea stars that people don't like are in the family Asterinidae. Reefers lump them all together as Asterina even though that's wrong. They reproduce by splitting in half - that's why they're asymmetrical. Some species or varieties definitely eat corals. The coral eaters seem to be the larger colored animals. Small, all white or pale ones tend to be harmless grazers.

 

[flyyyguy]

Leslie, Ive got some pictures for you somewhere of some small whitish ones chowing down on some polyps if you perhaps want them.

 

[LeslieH]

So much for that theory! :-D I came up with it after reviewing a couple years worth of posts here on RC & on other reefer forums. Nearly all of the images of coral eaters showed the bigger colored ones. Maybe they're just more photogenic.....

 

[ctniners]

flyyyguy, please post your pics, it would be interesting to see them.

Thanks

 

[circusink22]

i have those little white stars no color to them they graze on the glass and rock at night ive read that the sars that eat the coral are a little bigger and have some color to them

 

[flyyyguy]

size and color mean nothing IME

where you see them grazing most certainly does

ctniners- Ive been looking for the pic you requested........i have thousands of pics up loaded to my photobucket account and I have recently moved to a place where the best I can do as far as internet is a failry slow 3g connection. Its difficult to say the least to find a pic if I dont know exactly where I put it. Im not even positive I uploaded it to photobucket in the first place, but I will come across it and I will remember the 1/2 hour I spent looking for it when I do. I will post it when I find it.