About Berthella plumula (Montagu, 1803)
Berthella plumula (Montagu, 1803) is an oval-shaped sea slug that has an internal shell. The internal shell can grow up to 30 mm (1.2 in) long, while the entire body reaches up to 60 mm (2.4 in) in length. Its body ranges in color from cream to orange, and often has reticulate markings. The head is flat, and a large oral veil sits between the propodium and the mantle. Its rhinophores are protruding and enrolled. This species has acid glands in its skin that secrete sulphuric acid for protection when it is in danger. Berthella plumula is distributed in the north-eastern Atlantic, the Mediterranean Sea, the English Channel and the North Sea. It is a hermaphroditic species: two individuals reciprocally fertilize one another by exchanging sperm. Its reproductive season takes place in spring, and its egg masses are tube-shaped, with eggs arranged in a spiral.
