Ecteinascidia nexa Sluiter, 1904

KOTT, PATRICIA, 2003, New syntheses and new species in the Australian Ascidiacea, Journal of Natural History 37 (13), pp. 1611-1653 : 1637

Ecteinascidia nexa Sluiter, 1904

Ecteinascidia nexa Sluiter, 1904: 11 ; Kott, 1985: 94; Nishikawa, 1986: 42 and synonymy (including E. nexa: Kott, 1981: 196 ).

Ecteinascidia aequale Monniot, C., 1987: 25 .

Distribution. Queensland (Hervey Bay, Great Barrier Reef), Lord Howe I., Indonesia, Sri Lanka.

Remarks. Specimens from Fiji (Kott, 1981) have been re-examined and their identity confirmed. Kott (1985) thought Ecteinascia tokaraensis Tokioka, 1954 a synonym of the present species, but it was re-examined by Nishikawa (1986) and found to be a synonym of E. garstangi Sluiter, 1898 . Like the present species, it lacks stomach ridges, has transverse muscles across the dorsal mid-line anterior and posterior to the atrial siphon, and male follicles in a circle around the central ovary. However, in E. garstangi the testis follicles are separate and do not form a crowded compact mass as in the present species. As well as the compact testis in the gut loop, the network of blood vessels in the test (making it cloudy) and the radial muscles from both siphons which project beyond the circular siphonal muscles, the short stolon and mutiplicity of connections between zooids and substratum help to distinguish E. nexa from E. garstangi .

Ecteinascidia aequale Monniot, C., 1987 from New Caledonia is not sufficiently different from E. nexa for it to be a different species. Although 21–24 rows of stigmata have been recorded for E. aequale the range from 13 to 20 is recorded for E. nexa (see Kott, 1985; Nishikawa, 1986) and demonstrates the variation that can be expected.