What kind of worm is this?

[aquariumgirl]

I see this little guy (about 2 inches long) on my glass every now and again. It hasn't really grown since the first time I saw it about 6 months ago. I thought it might be a medusa worm or a small cuccumber. Is he okay in a reef tank?

 

[steve-s]

http://www.advancedaquarist.com/issues/nov2002/invert.htm

 

[hooked82]

Yep, they're on that page. Also says they're not suitable for a reef tank.

 

[aquariumgirl]

I'm reading a contradiction between the caption and the article, one says that "I think that these animals make a fantastic addition to a reef tank" and another says "but they are not suitable for the reef aquarium". Well, I've hadn't had any corals fall out of any spots and they seem to be doing well, I think I'll leave them for now. Maybe if it comes out onto the glass again, I can fish it out.

Thanks for the great article Steve-s!!

 

[steve-s]

A bit contradictory yes but basically what it comes down to is this. Unless you can meet their nightly feeding requirements and environmental needs, they should be passed on. In terms of reef additions, it's merely stating they are not harmful to their surroundings and an interesting animal.

 

[LeslieH]

Not exactly... It's a polychaete, family Phyllodocidae. One common name for them is paddle worm because the paired dorsal appendages along the body are often leaf- or paddle-shaped. Harmless for your tank.

 

[steve-s]

Leslie, thanks for the correction. I am curious though, on the above worm, I do not see the paddles you are referring to? Or are those the ridges?

 

[LeslieH]

The overall appearance reminds me of a Nereiphylla species. Take a look at this image and you'll see the overlapping dorsal cirri (the paddles) along the sides and the proportions of the antennae and the body.
http://www.calacademy.org/research/izg/SFBay2K/nereidworm2.htm

 

[steve-s]

Thanks Leslie!

 

[aquariumgirl]

Thanks for the info steve and leslie, I'm glad it's reef safe!! I do have another worm for you both to identify, but I'm having a hard time getting a picture.

It's very similar to the one above, but it lives at the base of the live rock and the sand. It doesn't look like a bristleworm, it has longer feeler or tentacles and it scavanges for pellets and flakes on the sand (it doesn't leave it's home just what it can find around it's doorway). It likes to gather shells, zoanthids and rocks to extend it's entrance. When something disturbs it it retracts quickly into its cave/burrow. I'm guessing it might be the same as the one pictured above just another species? It doesn't seem interested in any of the hermits, snails, fish or corals (other then using them to make it's door). Any ideas? I'll keep trying for a picture.

 

[steve-s]

Sounds like a Eunicid?

 

[LeslieH]

Without a picture it's hard for me to know if it's a terebellid (spagetti worm), an eunicid, or something else. Unless your pics are totally out of focus I should be able to get it to family.

And now for the obligatory lecture (I'm a worm taxonomist, forgive me)....
All polychaetes are bristle worms -- that's what the name means. Poly = many, chaeta = bristles. The animals commonly called bristleworms by reefers belong to the family Amphinomidae. The big amphinomids - Eurythoe, Hermodice, etc. are what I would call fireworms because their big bundles of white setae hurt like fire when you touch them. What's confusing to me is that many reefers use the term bristleworm for all sorts of worms so I'm never sure what a "bristleworm" post is really about until I see a pic!

 

[aquariumgirl]

ah, gotcha! Thanks for the info. It doesn't look like a Eunicid (tentacles a little longer), terebellid (tentacles not that long) or a fireworm just by looking at photos in a google search. I'll try to get a picture.