Peraclis rissoides

Peraclis rissoides Tesch, 1903
[dubious species]


This is a pelagic snail with a left coiled shell, 0.2 cm in height; it has 4.5 whorls and a deep suture without radial crests. The spire is not depressed. A keel is present but does not have an aperture tooth. The aperture is wide and oval, the base of the aperture is pointed towards the keeled rostrum. The shell surface shows a regular sculpture of a reticulate pattern. The wings are fused into a swimming plate. This species usually lives at great depths in all oceans (Peraclis rissoides).

Taxonomic Description

The shell most resembles Peraclis reticulata with the same reticulate structure disappearing near the aperture. The whorls, 4.5 in number, do not grow as rapidly as in Peraclis reticulata, and the aperture is somewhat smaller. An umbilicus is absent. The colour of the shell is reddish to yellow. The rostrum, which may be well developed according to Tesch (1903) has a small columellar membrane. The operculum has 5 to 6 whorls and does not show radial striae.
Shell measurements (of holotype): height 1.75 mm, diameter 1.40 mm.


The juveniles have a small left coiled shell. A special description is not available.


This species is a protandric hermaphrodite.


This species is phytophagous and mesopelagic.


Supposed distribution is Circumglobal, see the Peraclis rissoides map.


Peraclis rissoides Tesch, 1903: 11(1904), pl. 1, figs. 5, 6, 11, 13, 14.
Holotype: ZMAN (alcohol collection) u.s.
Type locality: 4°30'2 S 129°25'E. Coll.: Siboga, stat. 243.