Chromodoris geometrica-Nudibranch Facts and Photographs

Chromodoris geometrica is a dorid nudibranch, a marine gastropod mollusk that is also known by its common name of the Geometric Chromodoris. They were initially described in New Caledonia in 1928 by Risbec as Goniobranchus geometricus but in 2012 Johnson R.F. & Gosliner T.M conducted DNA analysis and they were revised as falling within the Chromodoris genus.

APPEARANCE

Chromodoris geometrica have an elongated oval shape and tubercles of different sizes spread across the body. The body colour is a light pink and there is a black or dark purple line circling the body around the gills and rhinopores which has a short line extending off onto the posterior section behind the gills . The rhinophores and gills are white and tipped with green. They grow up to 7 centimeters in length.

CHROMODORIS GEOMETRICA IN THE WILD

Chromodoris geometrica are not that common in Tanzanian mainland waters, but when one sees one, one will generally see a few more for a few weeks and then not see any for quite some time. Studies by Vladivostok University have shown that C. Geometrica have unusual long chain fatty acids and other bioactive compounds which may be useful for medicinal purposes.

HABITAT

Chromodoris geometrica are found across the Indian ocean and in the west Pacific.

DIET

Chromodoris geometrica feed mainly on certain species of sponges. The chemicals synthesized by bacteria in the nudibranch from these sponges provide them with chemical protection against predators.

REPRODUCTION

Chromodoris geometrica are simultaneous hermaphrodites and mating takes place by connecting the sexual organs which are on the right hand side of the body. Two specimens manouvre right side on and extend their organs towards each other. Once the two organs hook up sperm is transferred across to each specimen. Eggs are laid on a solid substrate in a gelatinous egg ribbon and when they hatch the larvae or veligers as they are known become planktonic before growing into adults.

Interestingly C. geometrica have been found to deposit yolk into their egg ribbons which provide food for the new hatched veligers. It is thought that this allows the veligers to be larger than other species that do not exhibit such behavior.

CHROMODORIS GEOMETRICA CLASSIFICATION

Kingdom:Animalia
Phylum: Mollusca
Class: Gastropoda
Subclass:Heterobranchia
Infraclass:Euthyneura
Order: Nudibranchia
Suborder:Doridina
Superfamily:Doridoidea
Family: Chromodorididae
Genus: Chromodoris
Species:C. geometricus