De Blainville, 1817
A very large shelled pelagic snail, with an almost completely transparent body. The body is long and cylindrical with one swimming fin. The shell is low conical with a high keel. The snail cannot withdraw its body into the shell. The body whorl is large with coarse transverse striation. The visceral nucleus is found on a very short stalk. The rounded dorsal fin is found opposite the nucleus with a fin sucker in both sexes [C.l.lamarckii-photo1, C.l.lamarckii-photo2]. The muscle bundles in the fins are well separated. A thick gelatinous cutis surrounds the trunk. Tubercles frequently cover the cutis. The tail is similar to the trunk and has a ventral tail keel and an unpigmented clasper.
Shell calcareous, transparent, only covering the visceral nucleus and is frequently lost in collections. The shell is broad pyramidally-shaped with the protoconch, the only part with whorls, on top [C.l.lamarcki-shell C.l.lamarckii-top].
Juveniles have a small, dextrally coiled shell. There are 4 whorls, the spire is high [C.l.lamarckii-protoc]. There are sometimes 2 spiral lines on one entire larval whorl. The width of the last whorl is 1/3 of the shell diameter. The velum has 6 lobes with brown rim, each with one brown spot. The tentacles are colourless. The mantle is brown. The operculum is rounded in outline and shows a clear spire with growth lines. It is composed of two separate 'blades', a small inner and a larger outer one connected to each other in the centre [C.l.lamarckii-protoc, C.l.lamarckii-juv].
Body almost completely transparent, only the broad triangular visceral nucleus is darkly pigmented. The large eyes, with black retina, and the mouth organs are clearly seen. The intestine is frequently full and visible. The tail is transparent with a ventral tail keel and an unpigmented clasper.
Maximum body length: up to 220 mm long.
Carinaria lamarcki is carnivorous and hunts large prey such as fish, shelled pteropods and other heteropods. In this species the sexes are separate.
Distribution in the North Sea
Unlikely to be found in the North Sea.
A cosmopolitan species with a wide north-south range from 60°N to 45°S. More abundant in the N Atlantic compared to the S Atlantic. Common in the Mediterranean; only few a few records from the Indo-Pacific Ocean; scarce in the Indo-Malayan area.
Shell may be lost upon fixation.
[After Van der Spoel et al., 1997]