Worm + Snail ID

[Reefmack]

After 8 months of watching for them at night I finally noticed what I'm pretty sure is a bristleworm? It's at least 4 inches long with the back end partially visible on the lower right. I never did see exactly how long it stretched as it went back into the rock after taking a few flash pictures.

There's also a pretty black & white snail on the right side, that I see fairly frequently at night. I honestly don't recall buying this one so it may have been a hitchhiker. It also appears to have a striped proboscis. Any IDs on this one?

Thanks

 

[pagojoe]

Don't know about your worm, but the snail is a juvenile Engina species, probably Engina histrio. It's predatory, but likely won't be much of a problem in your tank. I believe this is one of the species that feeds mainly on tiny vermetid snails. It is almost adult, and will add about one more whorl to the shell before it forms the adult lip and stops growing.

Cheers,



Don

 

[Reefmack]

Thanks pagojoe - great ID! I did some searching after your post and it does indeed look like either Engina histrio or Engina carolinae, and what little information I found confirmed what you said - predatory, and possibly even on small worms & crustaceans per a reference supposedly from Dr Shimek.

http://meri.akvarist.ee/viewtopic.php?p=6376&sid=240c992a10b7db7539ded4da0dea5407

Since my rock was Idonesian, and the Engina histrio and carolinae are found in Indonesia, it would all make sense. Now I'm not sure I want to leave the snail in the tank.