This mushroom coral has a tenant. There's a tiny siphon peeking out through its polyps. It belongs to a marine snail called Leptoconchus, which spends its entire adult life inside a snail-sized cavity in the coral’s skeleton. A coral doesn’t leave gaps in its calcium carbonate skeleton that a snail can squeeze into, so larval Leptoconchus bore their own way in. Once they’ve dug out their cavelike home, you need a hammer to get them out again.
There are several species of Leptoconchus spread around the Indo-Pacific basin. The snails all look very similar. Until recently they were classified in 6 species, each of which could be found in several species of coral. But when Adriaan Gittenberger compared their DNA while working on his dissertation at the National Museum of Natural History in Leiden, he discovered that there were really at least 18 species of Leptoconchus, and each species was only found in a single species of coral.
His beautiful pictures of these animals and other parasitic gastropods can be found here.
Gittenberger, A. and E. Gittenberger 2006
A largely cryptic, adaptive radiation of parasitic snails: sibling species in Leptoconchus (Gastropoda: Caenogastropoda: Coralliophilidae) associated with specific coral hosts (Scleractinia: Fungiidae)
Photo credits:
Above the fold: A. Gittenberger
Below the fold: B.W. Hoeksema
ooooh!
Posted by: Drhoz! | September 13, 2007 at 08:15 AM