Two-Spotted Dorid

Thordisa bimaculata

The Two-spotted Dorid is a species of nudibranch that displays a base coloration that can range from white to pale yellow and orange. It is characterized by two small dark brown spots on its mantle, one located behind the rhinophores and the other in front of the gills. The visibility of these spots can vary based on the individual, especially if they are covered by sand or other debris. This species typically reaches a length of about 28 mm and has a rounded body shape with a squat, pointed posterior and retractable gills. Additionally, it features two slender, fingerlike tentacles near its mouth. This nudibranch inhabits the eastern Pacific coast, particularly along the shores of California and Baja California. It is commonly found in rocky intertidal zones and can be observed at depths of up to 33 meters. Most sightings are concentrated in the Southern California Bight, with a higher frequency during the summer months when the water is warmer. As a simultaneous hermaphrodite, the Two-spotted Dorid exhibits interesting mating behaviors, where individuals compete for dominance to inseminate one another. Their eggs are laid in coiled ribbons attached to rocky substrates. This species primarily feeds on sponges, playing a role in the benthic ecosystem. The conservation status of the Two-spotted Dorid has not been evaluated, but it can be found in various marine environments.