Hunchback Doris

Atagema alba

Atagema alba, known as the Hunchback Doris, is a species of sea slug that belongs to the family Discodorididae. This nudibranch can be identified by its distinct shape, which features a pronounced hunchback appearance. A typical individual measures around 30 mm in length and 11 mm in width. They inhabit the eastern Pacific, specifically from Monterey Bay in California down to Ensenada in Baja California, Mexico, typically found in benthic environments. This species primarily feeds on sponges, utilizing its specialized anatomy to graze on these organisms. As a simultaneous hermaphrodite, Atagema alba engages in unique mating behaviors where individuals may alternate roles during copulation, with one acting as a male and the other as a female. After mating, they deposit eggs on a suitable substrate, which then develop into a planktonic larval stage before maturing into adults. Diving encounters with the Hunchback Doris can be intriguing, as they often crawl slowly along the seafloor, blending into their surroundings. Observing their feeding behavior on sponges can be particularly interesting for divers. The conservation status of Atagema alba has not been evaluated by the IUCN, indicating a lack of comprehensive data on its population trends.