The Conchological Society of Great Britain and Ireland | Helping to understand, identify, record, and conserve molluscs

Onchidoris sparsa. 7.5mm (longer when extended). 1: Ground colour pinkish, seen in lines dissecting brown pigment. 2: Pale lines alternate with dark blocks around periphery. Click “View image details” for 3 –8.

Species

Knoutsodonta sparsa (Alder & Hancock, 1846)

Photographer / copyright holder

I.F. Smith

3: Pale tubercles coated translucent grey-brown, appear as pale spots outlined in grey on dorsum when viewed from directly above. 4: Lamellae on rhinophores dark, thick and widely spaced.

Onchidoris sparsa. Dorsal view of specimen with little brown pigment. Diagnostic pale area at base of rhinophores. Faint suggestion of alternating pale and dark bands round periphery. From Alder & Hancock monograph.

Onchidoris sparsa. Lateral view, low profile. From Alder, J. & Hancock, A. 1845-1855. A monograph of the British nudibranchiate mollusca. London, Ray Society.

Onchidoris sparsa. Anterior and lateral views of rhinophore. Apex truncated. Translucent pale greyish with up to nine widely spaced, robust, dark, oblique lamellae. From Alder & Hancock. A monograph of the British nudibranchiate mollusca.

Onchidoris sparsa. Foot, nearly as wide as mantle. Sole translucent whitish, showing central elongate orange-brown, or brownish-salmon, liver. Large oral veil and large oral orifice. From Alder & Hancock. A monograph of the British nudibranchiate mollusca

Onchidoris sparsa. 7.5mm (longer when extended). 1: Ground colour pinkish, seen in lines dissecting brown pigment. 2: Pale lines alternate with dark blocks around periphery. Click “View image details” for 3 –8.

Onchidoris inconspicua. Spawn on prey, Cellepora pumicosa. From Alder, J. & Hancock, A. 1845-1855. A monograph of the British nudibranchiate mollusca. London, Ray Society. (as Doris inconspicua).

Onchidoris inconspicua. Rhinophore; anterior and lateral views. Lamellae closely spaced. From Alder, J. & Hancock, A. 1845-1855. A monograph of the British nudibranchiate mollusca. London, Ray Society. (as Doris inconspicua).

Onchidoris inconspicua. Sole showing liver. From Alder, J. & Hancock, A. 1845-1855. A monograph of the British nudibranchiate mollusca. London, Ray Society. (as Doris inconspicua).

Onchidoris inconspicua. From Alder, J. & Hancock, A. 1845-1855. A monograph of the British nudibranchiate mollusca. A&H drew their illustration from two specimens which seem to have lacked larger black flakes on mantle.

Onchidoris inconspicua. Spawn on polyzoan prey. Spiral 7mm diameter. Orkney. May 1975.