Dorids

Dorids are a diverse group of shell-less marine gastropod mollusks, commonly called dorid nudibranchs. They belong to one of the major lineages of Nudibranchia and are found in oceans worldwide, from shallow reefs to deep sea.

Anatomically, dorids typically have a broad, flattened body with a mantle that can cover the dorsum. A defining feature is the circlet of gills on the posterior dorsal surface, the branchial plume, which can be retracted under the mantle when threatened. They lack the cerata characteristic of many other nudibranchs. The head bears two rhinophores, which detect chemical cues in the water, and a well-developed mouth surrounded by a toothed radula.

Diet and defense: Most dorids feed on sponges, but some feed on bryozoans or tunicates. They often accumulate defensive chemicals from their prey and display vivid coloration as a warning to predators, a phenomenon known as aposematism.

Life cycle and behavior: Dorids are hermaphrodites; during mating two individuals exchange sperm and later lay eggs in gelatinous ribbons or spirals that hatch into free-swimming veliger larvae.

Taxonomy and diversity: Dorids encompass several families within the doridoidean lineage, including Chromodorididae and Discodorididae. They represent a wide range of colors and patterns and are frequently studied for their chemical ecology and ecological roles in marine ecosystems.