Krohn's Dorid

Overview

Krohn's Dorid (Felimida krohni) is a vibrant, small nudibranch belonging to the family Chromodorididae. It is widely recognized for its striking coloration and distinct longitudinal markings, which serve as a warning to potential predators.

Distribution & habitat

This species is native to the eastern Atlantic Ocean, ranging from the British Isles south to Cape Verde, and is also found throughout the Mediterranean Sea. It typically inhabits rocky substrates, including walls and areas under rocks, where it can be found from shallow waters down to approximately 30–50 meters. It is often associated with environments that support sponges, hydroids, and bryozoans.

Appearance

The body of this nudibranch is elongated and typically measures between 15 and 30 mm in length. Its mantle displays a base color ranging from pink and mauve to pale blue, often featuring an iridescent blue or mauve border edged with a thin yellow line. The dorsal surface is characterized by three longitudinal white or yellow lines—which may be continuous or broken—and sometimes includes additional yellow spots. Its rhinophores and branchial plumes are deep purple and can be retracted when the animal is disturbed.

Biology & behavior

Felimida krohni exhibits aposematism, using its bright colors to signal its toxicity to predators. It sequesters chemical defenses from the sponges it consumes, making it distasteful. Like other nudibranchs, it is a hermaphrodite, possessing both male and female reproductive organs.

Feeding

This species is a specialized sponge feeder. It uses its radula, a tongue-like structure with tiny teeth, to scrape fragments from sponges, including species within the genus Ircinia and Hymeniacidon.