Styela canopus

Styela canopus (Savigny, 1816)

Cynthia canopus Savigny, 1816:45

Styela marquesana: Michaelsen 1918, 27. Millar 1955: 207, South Africa; 1960:191, Mozambique and Natal. Plante & Vasseur 1966: 150, Madagascar.

Styela canopus: Kott 1985:112 and synonymy. Monniot & al 2001:101, fig. 49A, South Africa, and synonymy.

Stations. TR 7 (MNHN S1 STY 315). TR 16 (MNHN S1 STY 316).

This species is precisely described by Michaelsen (1918) under the name Styela marquesana but the author includes it in the S. canopus group. (p.33). Later on several authors used the species name S. marquesana for material from the south western Indian Ocean. Kott (1990) united all world wide material with the same anatomy as synonyms under a single name S. canopus owing to the absence of discriminating characters. This name likely corresponds to a group of species.

The specimens from the south of Madagascar have a brown tunic covered with epibionts. The internal lining of the siphons have alternate red and yellow stripes with numerous triangular spinules. The anatomical characters have been described by several authors: a branchial sac with 4 low folds, an elongated stomach, a close gut loop with a lobed anus, 2 gonads on each side, numerous endocarps and a atrial velum with numerous thread-like processes.

In absence of discriminating characters the general name Styela canopus is used here.