Facelinidae Family of Nudibranchs
One Nudibranch of the Facelinidae Family can be found in this website:
Las Cruces Aeolid, Phidiana lascrucensis. A representative of the Facelinidae Family of Nudibranches.
Phylogeny: Nudibranchs of the Facelinidae Family are Sea Slugs in the phylum Mollusca. They are in the class Gastropoda, the subclass Heterobranchia, the infraclass Euthyneura, the subterclass Ringipleura, the superorder Nudipleura, the order Nudibranchia, the suborder Aeolidina, and the superfamily Aeolidioidea. The Facelinidae Family is one ten families in this superfamily. The Facelinidae Family is large, with five subfamilies, thirty-one genera, and around one hundred forty-one species.
Morphology: Facelinidae nudibranchs are soft-bodied gastropods that have an elongated deep body, often with a tapering tail. These nudibranchs have regular rows of cerata on their dorsal surface, which may be club-tipped, coiled, curved, tapering or tubular. They have long oral tentacles and rhinophores. Rhinophores are horn-like projections on their heads that are chemosensory organs that help them to locate food and potential mates. Their rhinophores have numerous rings or collars. Their radula has a single row of teeth. The anterior end of the foot is angular. The anus is more anterior than Aeolididae Nudibranchs. They lose their shells during their larval phase. Nudibranchs lack complex eyes, but have photo-receptors that sense light and dark. 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 eat. Facelinidae nudibranchs range in size from less than 1.0 cm (0.4 inches) to more than 8.0 cm (3.1 inches) in length.
Distribution: Facelinidae Nudibranchs are found on, or under, rocks, in crevasses, and on vertical and overhanging surfaces. They live in the intertidal zone and at depths up to 40 m (131 feet). Facelinidae Nudibranchs are found worldwide, in tropical to temperate waters. At least seven species from this family are found in Mexican waters.
Reproduction: Facelinidae Nudibranchs are simultaneous hermaphrodites (having male and female reproductive organs). They reproduce sexually by hypodermic insemination. This occurs when both mating partners dart their penis toward each other to induce one to act as a male and the other as the female. The victorious one to penetrate the body wall is the dominant male. The eggs are laid as a mass on the bottom stratum. The eggs hatch into veliger larva and later metamorphose into adults.
Ecosystem Roles: Facelinidae Nudibranchs are relatively fast moving, aggressive, predators feeding on algae, coral polyps and other cnidarians, and sea slug eggs. Some species store the stinging cells (nematocysts) from their food in cnidosacs at the end of their cerata, that they utilized to provide defense. Other species are zooxanthellate that have a symbiotic relationship with single-cell dinoflagellates, known as zooxanthellae. Zooxanthellae live within certain coral polyps, jellyfish, nudibranchs and sea anemones. The zooxanthellae produce energy, during daylight, by means of photosynthesis. This energy is passed along to their hosts, sometimes providing up to 90% of the host’s total energy needs. In return, the host provides nutrients, carbon dioxide, and a secure, sunlit, platform for the zooxanthellae. Facelinidae Nudibranchs are prey for fish, crabs, shore birds, sea turtles, and other sea slugs.