Caramel Nudibranch

Glossodoris rufomarginata is a species of colorful sea slug, a dorid nudibranch, a marine gastropod mollusc in the family Chromodorididae.

Other names: White-Margin Sea Slug.

Description

Glossodoris rufomarginata has a size commonly observed around 3,5 cm with a maximum of 5 cm length. The background coloration of the entire body is whitish with on the foot and the dorsal surface speckled with a dense coat of tiny red to orange-brown dots that gives the impression at first glance that the animal is brown. The edge of the mantle is well developed and wavy with a broad white band with a red to orange-brown outer border. The foot has also a white external margin. The rhinophores and branchial plume are retractable with a red to orange-brown coloration with a white median line on rhinophores and a white highlight on the gills axes.

Distribution

This species occurs in the tropical waters of Indo-Pacific area. It has been observed in localities as far distant from one another as Tanzania in Africa, Mayotte, but it occurs mainly from Sri Lanka to Polynesia and Hawaii.

Habitat

This nudibranch can be observed mostly on reef and rocky areas in sheltered as in exposed environment but with a preference for area in the shade. It also occasionally occurs in tide pools. Several animals often occur together on a dark gray sponge, Cacospongia sp. on which it feeds.

Biology

Glossodoris rufomarginata has a daytime activity and can be easily met on or in close proximity to its favorite food source which are some black sponges of the family Thorectidae. It has the ability to secrete toxic substances which provides protection against predators. They are simultaneous hermaphrodites and mating takes place by connecting the sexual organs which are on the right hand side of the body. Its egg masses are white and usually composed of about two whorls. They are typically laid on or near the host sponge.