Species of mollusc
Berthella plumula, commonly known as yellow-plumed sea slug, is a gastropod mollusc usually found on rocky coasts in the infralittoral zone[1] and which can live up to 30m depth.[2]
Description
Berthella plumula is an oval-shaped sea slug with an internal shell, which can be up to 30 mm (1.2 in) long. The body is up to 60 mm (2.4 in) and has a cream to orange colour and often displays reticulate markings. The head is flat and a large oral veil lies between the propodium and the mantle. The rhinophores are protruding and enrolled.[2] The species has acid glands in the skin which secrete sulphuric acid for protection in case of danger.[3]
Distribution
Berthella plumula is found in the north-eastern Atlantic, the Mediterranean Sea, the English Channel and the North Sea.[4]
Behavior
Diet
Berthella plumula is a slow moving predator which scrapes its radula on rocks to feed on colonial ascidians of the genus Botryllus as well as on Oscarella sponges.[1][2]
Reproduction
The species is hermaphrodite and the two individuals reciprocally fecundate each other by exchanging their sperm. The reproductive period occurs in spring. The laying is tube-shaped and the eggs are displayed in spiral.[4]
Similar species
Berthella plumula can be confused with Berthella stellata, which is smaller and displays a small white mark on its back, and with Berthellina edwardsii, which is usually bigger and more red.[4]
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Three specimens of Berthella plumula in Pula, Croatia
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Spiral eggs of Berthella plumula in Pula, Croatia
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Yellow-plumed sea slug in Pula, Croatia
References
