Cymbulia sibogae

Cymbulia sibogae Tesch, 1903
(also see the Cymbulia movie)


This is a shell-less pteropod, with a large cartilaginous slipper-like pseudoconch, 2.4 cm long. The wings are disc-shaped and the visceral mass forms a dark nucleus embedded in the perfectly transparent pseudoconch. The pseudoconch is pointed and covered with cusps. It is an elegant swimmer that feeds by means of a mucous web on microplankton. It is found throughout warm waters of the Indian Ocean (Cymbulia sibogae 1).

Taxonomic Description

The slender pseudoconch is much smaller compared to Cymbulia peroni though it is similar in structure (Cymbulia sibogae line drawing, Cymbulia sibogae). The rows of spines are arranged as in Cymbulia peroni morpha peroni. The spines, near the opening of the cavity, are absent or extremely small. The dorsal end of the pseudoconch is pointed. The two rows of spines ending at the ventral points do not have a constriction in the middle, being almost straight throughout their length; the pseudoconch does not show a medial constriction. The anterior end is slightly hollow and provided with small spines. According to Tesch (1904) the anatomy is similar to that of Cymbulia peroni.
The pseudoconch varies in length from 11 to 24 mm.


A special description is not available.


This species is a protandric hermaphrodite.


This species is phytophagous.


This species has a Atlanto-Indian ocean distribution, concentrated around the centres of the S-Atlantic and Indian Ocean mainly between 30°N and 40°S. A small penetration into the W-Pacific Ocean is found. This Pacific population is not a major presence as it concerns only an eastward spread of populations, see the Cymbulia sibogae map.


Cymbulia sibogae Tesch, 1903: 113 (1904), pl. 3, figs. 88-90.
Lectotype: ZMAN (alcohol collection). Paralectotypes: ZMAN, 12 spec. (alcohol collection).
Type locality: 2°22'S 126°46'E. Coll.: Siboga, stat. 189a.