[BubbaWPB]

I found this critter in my tank yesterday. It's about 3/4 inch long and about half as wide as it is long. I've done some looking around and it appears to be a "scale worm." Now that I sorta know what it is, does anybody know if it's gonna breed uncontrollably and eat all my coral?

[Reefland]

Hi Bubba!

I replied to this in your gallery, what you have is a Chiton. They are non-harmful algae grazers and would be considered a welcome addition. You can do a search on the term Chiton here and will find more information if your interested.

[Ninong]

Yes, it is definitely a chiton. A scale worm is a short worm with 12 pairs of overlapping scales: http://www.mesa.edu.au/friends/seash...nogrammus.html

A chiton is a mollusc with 8 overlapping and separate plates forming the shell: http://nighthawk.tricity.wsu.edu/mus...s/Chitons.html

In your picture, you can easily count the 8 plates that form the shell.

[zhenya]

Now that I sorta know what it is, does anybody know if it's gonna breed uncontrollably and eat all my coral?

Now that you know what it is,here's another bit of information about Chitons, curtesy of Dr.Shimek..


...Reproduction in chitons follows a basic pattern that is similar to other “primitive” mollusks. The sexes are generally separate, and hermaphroditism is rarely reported in this group. Temperate chitons spawn once a year — reproductive data concerning the tropical chitons are sparse. Both genders spawn into the water, and, consequently, there is no sexual dimorphism.
The eggs are large and yolky. After fertilization the embryos develop quickly into a rapidly swimming non-feeding larva. This larva develops seven grooves across its back where the first seven shells will form, and settles out of the plankton, generally on some rock made tasty by the addition of a coralline algal coating. After settling, there is no drastic metamorphosis. The animal gradually changes into a miniature chiton. Seven shells develop initially and the eighth follows within a short period. Juvenile chitons on the rocks grow slowly and it may take quite a while to reach a few millimeters in length.

Growth has not been measured in tropical chitons, but in one common eastern Pacific species, Katharina tunicata, the growth rate appears to be about 1 millimeter (1/25th of an inch) per year. As Katharina may exceed 4 centimeters (1 1/2 inches) in length, it is reasonable to assume that the animals may live at least 40 years. This species likely becomes sexually mature at about 15 to 20 millimeters (6 to almost 8 inches) in length, so at about the age of 15 to 20 years.

Here's the link to entire article
http://web.archive.org/web/200208150...wb/default.asp

Basically what I am trying to say is no worries....

[BubbaWPB]

Thanks a bazillion, y'all!

[saltjunkie]

wow.. i have.. all covered in coraline.. i was wondering what it was and di..
i know for a fact that you cant easily dislodge it from a rock!

[BubbaWPB]

http://www.reefland.com/gallery/file...n_original.jpg
It's still in the tank and about twice the size it was. Here's the same pic with the chiton circled.

[zhenya]

I'm glad it;s doing good for you, Bubba. Not all Chitons survive for long in tanks, especially the ones that hitch hike. I had one for almost a year only to disappear and never to be seen again.
I think their grazing of live rock from coralline and other algae makes it more porous again and more of a filtration media, rather than just a place to mount corals to.