Polyandrocarpa anguinea (Sluiter, 1898)

Monniot, Françoise, 2018, Ascidians collected during the Madibenthos expedition in Martinique: 2. Stolidobranchia, Styelidae, Zootaxa 4410 (2), pp. 291-318 : 296

Polyandrocarpa anguinea (Sluiter, 1898)

Fig. 5

Styela (Polycarpa) nivosa Sluiter, 1898

Polycarpa nivosa: Van der Sloot 1969 ; Monniot C. 1983 and synonymy. Polyandrocarpa rollandi Tokioka 1961

Polyandrocarpa rollandi: Monniot C. 1987

Polycarpa anguinea: Monniot C. & F. 1994 ; Monniot C. 2002 Polyandrocarpa anguinea: Vasseur 1967 ; Rodrigues 1977; Rocha & Costa 2005; Rocha, Moreno & Metri 2005. Station: AB 155 (MNHN S1 POL.A 59)

The zooids form a compact mass from which emerge some siphons ( Fig.5A ). The tunic is clear cartilaginous with furrows and wears sand and epibionts. The body wall is thin, marbled with brown pigment with a thin musculature. The large velum of both siphons has round vesicles containing crystalline material. There are 8 oral tentacles separated by smaller ones. The prepharyngeal area has no papillae. The dorsal tubercle is U-shaped. The branchial tissue is thin with 4 well separated folds on each side ( Fig.5B ). One example of branchial formula is from the right to the left side:

E (16) 6 (19) 7 (17) 6 (15) 4 DL 2 (12) 6 (16) 6 (17) 6 (14) 6 E.

This formula is similar to those given by Van der Sloot (1969). It differs from the formula in P. arianae in having fewer vessels in the folds and only one longitudinal vessel between the first dorsal fold on the right and the dorsal lamina ( Fig.5B ). There are 3 to 4 stigmata in a mesh. Parastigmatic vessels are present everywhere.

There are no endocarps on the internal side of the body wall. The gut is only linked to the body wall by trabeculae. The stomach is ovoid with internal folds and without caecum. The wide primary loop does not contain endocarps. The anus is lobed. The gonads were not numerous in the Madibenthos colony (with 8 polycarps on the right side and 7 on the left side). In another specimen from Martinique which was provisionally described as Polycarpa nivosa? (Sluiter, 1898) by Monniot C. (1983) there were more than 25 polycarps on the right body side. Each polycarp is elongated with 2 rows of testis vesicles under the ovary. The gonads are only linked by trabeculae to the body wall and to the branchial sac.

The distinction between the different Polyandrocarpa species is essentially based on the branchial formula and the presence of endocarps. P. anguinea and P. arianae could be easily confused but among the numerous specimens collected from several regions the specific differences remain constant. P anguinea has a wide geographic distribution:

South Africa, Brazil, Caribbean Sea, Florida in the Western Atlantic, but also Sierra Leone in the eastern Atlantic, Mozambique and Mauritius in the Indian Ocean and in the tropical Pacific Ocean ( Monniot 1987).

Comments about the systematic position of Polycarpa and Polyandrocarpa were given in Monniot C. & F. (1994) describing in details African specimens as Polycarpa anguinea , the question concerning true colonies or only agglomerated zooids.

Figures

FIGURE 5. Polyandrocarpa anguinea. A, colony, scale bar = 1cm; B,branchial tissue stained, scale bar = 5mm.