Pyura obesa Sluiter, 1912

Primo, Carmen & Vázquez, Elsa, 2007, Ascidians collected during the Spanish Antarctic expedition CIEMAR 99 / 00 in the Bransfield and Gerlache Straits, Journal of Natural History 41 (29 - 32), pp. 1775-1810 : 1804

Pyura obesa Sluiter, 1912

Pyura obesa Sluiter, 1912 ; Sluiter 1914; Van Name 1945; Kott 1969, 1971; Monniot and

Monniot 1983; Tatián et al. 1998a, 1998b; Ramos-Esplá et al. 2005 (non Hartmeyer

1919).

Distribution

New record: Bransfield Strait (Station B7: one specimen). Previously recorded: South Shetland and South Orkney Islands ( Monniot and Monniot 1983; Tatián et al. 1998a, 1998b; Ramos-Esplá et al. 2005). From 22 to 220 m depth.

Description

We found one colony 98 mm height plus a stalk of 45 mm. The tunic is thick and fleshy. The branchial siphon is directed downward and the atrial one, sessile, is just above. The dorsal tubercle is a double cone and the horns, both of them forming a spiral towards the right, have a convoluted course. One gonad on each side. There are two endocarps that cover the right gonad and the gut together with the left gonad, respectively. The gonoducts are very long and they open near the atrial siphon.

Remarks

Although variable in external appearance, this large species has a series of distinctive characteristics. We agree with Monniot and Monniot (1983) that there is only one gonad on each side and that probably Kott (1969) confused the heart, well developed and covered with an endocarp too, with a second right gonad.