Bathypera splendens ( Michaelsen, 1904 )

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 : 1802-1803

Bathypera splendens ( Michaelsen, 1904)

( Figure 18 )

Bathypera splendens Michaelsen, 1904 ; Hartmeyer 1911; Herdman 1923; Van Name 1945; Vinogradova 1962; Millar 1960; Kott 1954, 1969, 1971; Monniot and Monniot 1982, 1983, 1994; Ramos-Esplá et al. 2005.

Pyura liouvillia Sluiter, 1912 ; Sluiter 1914.

Bathypera hastaefera Vinogradova, 1962 ; Kott 1969.

Distribution

New record: Bransfield Strait (Station B3: one specimen). Previously recorded: Antarctic continent, South Shetland and South Orkney Islands ( Kott 1954, 1969; Monniot and Monniot 1983; Ramos-Esplá et al. 2005); Tierra de Fuego ( Kott 1971).

Description

One ovoid colony, 21 mm height. The test is thin, but firm and tough. The surface is covered with minute papillae which contain, in the dorsal half of the body, calcareous spicules, typical of the species. Each spicule has numerous short spines in a slanting plane; near the siphons, the spicules are arranged with the oblique plane toward the siphon apertures. In the middle line of the body may be found a regular series of spine sizes, increasingly larger ones higher up.

Atrial and branchial siphons are almost sessile, bilabiate and directed anteriorly. There are 33 branched branchial tentacles of three sizes. The branchial sac has six very high folds on each side. The right gonad has split into two, although the ovaries are still fused together. The larger gonad has a double gonoduct ( Figure 18 ). There is a large testis lobe on the distal end of each ovary and smaller lobes along it, arranged without order.

Remarks

Our specimen differs from the type specimen in the number of ovaries (one on each side in the type) and the testis arrangement (many small lobes distributed along both sides of the ovary), but these kinds of variations are not unusual in deepsea species. However, in spite of these differences and after examining some specimens deposited at the MNHN, we concluded that our specimen belongs to B. splendens .

Figures

Figure 18. Bathypera splendens. (a) Right gonad; (b) left gonad in curve of gut. Dark structures are the testes.