Cardiapoda richardi Vayssiére, 1903
(also see the Cardiapoda richardi.mov movie)
This is a large naked pelagic snail with a completely transparent cylindrical body with one swimming fin, up to 2 cm long. The shell is very small and embedded in the visceral nucleus. Only the broadly rounded visceral nucleus is darkly pigmented, the large eyes, with a black retina, and the mouth organs are clearly visible. The intestine is frequently full and visible. It hunts large prey such as fishes, shelled pteropods and other heteropods. It lives mostly in the upper layers in the warm waters of all oceans (Cardiapoda richardi).
The most typical characters of this species are the small number of gills, up to eight near the opening of the pallial cavity and the large pigmented body in the eyes. The general body shape is similar to Cardiapoda placenta, however, the tail is filamentous, the fin has separate muscle fibres (not a homogeneous layer) and a pigmented expansion is found under the tail before the filamentous part. A fin sucker is only present in males. A shell has never been described for this species, but a coil in the top of the liver of small specimens proves that a small shell must be present after the veliger stage.
Body length up to 20 mm.
The juveniles have a small, dextrally coiled shell. The shell has 3.5 whorls, the last whorl is slightly flattened (Cardiapoda richardi juv.). There are two spiral lines on half a larval whorl. The width of the last whorl is 1/3 the shell diameter. The velum has 6 lobes with light brown rims. The right tentacle is brown, the left one is colourless. For the rest the animal is nearly colourless.
In this species the sexes are separate.
This species is a carnivore and epipelagic.
This species has been collected from typical oceanic localities, especially in the Atlantic and Indian Oceans. Though more records are known from the N-Atlantic, it does not avoid the equatorial currents, see the Cardiapoda richardi map.
Cardiapoda richardi Vayssiére, 1903: 24, pl. 4, figs. 58-60.
Holotype: MOM slightly dried out (alcohol collection) u.s.
Type locality: 40°28'43"N 36°32'42"W. Coll.: CPNE stat. 134.