Mystery Fish--Please help ID

[Peanut's_Pa]

http://reefcentral.com/gallery/data/500/64864Mystery_Fish_1.JPG http://reefcentral.com/gallery/data/500/64864Mystery_Fish_2.JPG

Last night I was viewing my tank about three hours after the lights went off. I found this unknown fish swimming in my tank. It is 3 1/2 to 4 inches long. It has two small fins under its gills and continuous fins down the length of its body. It swims much like an eel but resembles nothing I can find in any photos.

It has bronze-metalic look on the main part of its body when illuminated with flashlight. Otherwise it appears black in color.

Please help me identify this critter.

Thanks,

:confused:

[sagitariuscbc]

do you have a sea cucumber? the reason i ask because there is a fish that can live inside of them!
<img src="http://www.twize.com/images/welcome.gif">

[waterdevil1]

E-mail Bob Fenner at wetwebmedia and he will tell you all about it

[Peanut's_Pa]

No I do not have a cucumber and have never owned one. I have bought live rock at Capital Aquarium & Exotic Aquarium. I have also recent bought live rock from a site member but he doesn't recognize this fish either. I did have a star fish die recently but I don't know that the appearance of this fish is related.

[BoomerD]

I PM'd Peanut's_Pa last night with a bit of information on the Pearl fish, the one with the wonderful home in the "backside" oc cucumbers. That is what it looks like to me as well...There's VERY little info available on them, so it's tough to be sure. I agree about sending the pics to Fenner & his crew for a better I.D.
http://www.wetwebmedia.com/daily_faqs.htm Follow the links from here...

[JRHazer]

Looks like some kind of Dartfish.

[wombat2]

Definitely looks like a pearlfish to me as well. I wasn't aware they had ever been found as hitchhikers. You may have a cuke somewhere in your LR. How long has your tank been setup? Where is the rock from?

[wombat2]

Encheliophis gracilis, possibly. There are probably several spp., but this is one of them.

http://www.fishbase.org/Summary/SpeciesSummary.cfm?id=9204

[sagitariuscbc]

looks like it also lives in starfish.

from the link above that wombat2 posted.

Biology: Uncommon species (Ref. 34024). Lives in starfish (Culcita discoidea) and sea cucumbers (Holothuria scabra and H. argus). In the latter reported by Trott (1970) to form male - female pairs and to parasite host.

[beerguy]

If it is a pearlfish you really need to read this thread. (http://archive.reefcentral.com/forums/showthread.php?s=&threadid=124130&highlight=buttfish)

:D

[Peanut's_Pa]

Last week-end, my Purple Linkia which was about seven inches across died for no appearant reason. Perhaps it was in this starfish?

[wombat2]

A 4" fish in a 7" starfish? I doubt it. How long did you have the Linckia for? Linckias dying for no apparent reason is relatively common, unfortunately. They don't ship well.

I searched for a half an hour to find out if in fact pearlfish parasitize Linckia spp. and found nothing. The pics I've seen of pearlfish entering and exiting are of massive sea cucumbers the size of watermelons. I doubt a star that size could sustain a pearlfish for long, but it's just my best guess. It doesn't mean that the fish couldn't have killed your star, but I highly doubt that the fish entered your aquarium via the Linckia.

[wombat2]

...and just for a size comparison, here is a member of the Culcita genus that pearlfish naturally parasitize:

http://people.hws.edu/mitchell/postcards/Culcita.jpg

[jdieck]

Well it really looks like a "butt fish"
For some fun read this thread:

http://archive.reefcentral.com/forums/showthread.php?s=&threadid=124130&highlight=Angelas+butt+fish

[wombat2]

Wow. I really can't believe people thought that continuing to say butt-fish after 7+ pages was really all that funny.