Discodorididae Family of Nudibranchs

Two Nudibranchs of the Discodoridae Family can be found in this website:

Phylogeny: Nudibranchs of the Discodorididae Family are in the phylum Mollusca. They are in the class Gastropoda and the order Doridida.  Nudibranchs have “naked gills” exposed on their backs that are utilized to separate nudibranchs into two main classifications, the Aeolids and the Dorids. The Aeolids have a mantle that forms a series of finger-like projections (cerrata) along the entire back of the animal. The Dorids have a thick mantle on their back (dorsal surface) that extends over the foot. Their gills consist of feathery plumes that encircle the anus. The Discodorididae Family is one of two families in the superfamily Doridoidea. The Discodorididae Family contains thirty-one genera and around one hundred eighty species. The name Discodorididae comes from a combination of Latin and Greek words meaning “disk-like gift from the gods”.

Morphology:  Discodorididae Nudibranchs are soft-bodied Dorids. They usually have an oval outline and a flattened profile. Some actually resemble Flatworms more than nudibranchs. Their mantle is wide and thick, with the skirt extending over the foot covering the entire animal. The mantle may be smooth, ridged, tuberculate or pustulose in texture. Their foot is large relative to the animal. All nudibranchs have rhinophores (horn-like projections) on their heads which are chemosensory organs help them to locate food and potential mates. Their rhinophores are lamellate, often with raised sheaths and can be completely retracted into separate pockets. Their gills consist of feathery plumes that encircle the anus that are set posteriorly and can be retracted. Nudibranchs lack complex eyes but have photoreceptors that sense light and dark. They lose their shells during their larval phase. Despite their inability to see color, nudibranchs are some of the most brightly colored of all animals. They derive the pigments for their color from the food they consume. Species in this family range in size from around 3 cm (1.2 inches) to 20 cm (7.9 inches) in length.

Habitat and Distribution:  Discodorididae Nudibranchs are found on, or under, rocks, in crevasses, and on vertical or overhanging surfaces. Most are found intertidally or in shallow water, but some are found at depths greater than 200 m (656 feet). Discodorididae Nudibranchs are found worldwide in temperate to tropical seas. At least eighteen species from this family are found in Mexican waters.

Reproduction: Discodorididae Nudibranchs are simultaneous hermaphrodites (having both male and female reproductive organs). They reproduce sexually with internal fertilization.  After being fertilized internally, the eggs are laid in coiled, gelatinous, ribbons, attached to the substrate. The eggs hatch into veliger larva and later metamorphose into adults.

Ecosystem Roles:  Discodorididae Nudibranchs are specialized predators that eat sponges, with most species preferring only one species of sponge. This family exhibits a variety of dense mechanisms. Some species can shed a piece of their mantle to distract predators long enough to escape. The mantle will then regenerate. Others can secrete acid through their mantle. This acid provides a citrus scent to some species. Some can also swim to avoid predation. The primary predators of these nudibranchs are other nudibranchs.