Onchidella nigricans

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Onchidella nigricans
Scientific classification
Kingdom: Animalia
Phylum: Mollusca
Class: Gastropoda
Order: Systellommatophora
Family: Onchidiidae
Genus: Onchidella
Species: O. nigricans
Binomial name
Onchidella nigricans
(Quoy & Gaimard,1832)

Onchidella nigricans is a species of small, air-breathing sea slug, a shell-less marine pulmonate gastropod mollusc in the family Onchidiidae.

For more information on this unusual family of air-breathing sea slugs see Onchidiidae.

Contents

[edit] Distribution

This species is endemic to New Zealand including the Chatham Islands.

[edit] Habitat

This sea slug is found in the mid intertidal zone.

[edit] Description

This species, along with all others in the family, does not have a shell, and has the general appearance of a limpet.

Its dorsal surface is granular and has a rubbery, warty appearance with numerous papillae some larger than others. The coloration is normally uniformly black, but occasionally specimens with reticulated black and white and other patterns are encountered. From above, the animal is elliptical in outline with a crenate margin. The small head bears a pair of short, knobbed tentacles. At the hind end, between the foot and the back, is a conspicuous pore, the pneumostome, which is the opening of the lung. Onchidella nigricans uses this lung to breathe when the tide is out, and its moist skin to breathe when the tide is in.

[edit] Life habits

Onchidella nigricans moves across damp rocks very swiftly (for a gastropod), feeding on the surface film of minute plants and debris which it picks up with its hard radula.

[edit] References