Ecteinascidia sluiteri Herdman, 1906

KOTT, PATRICIA, 2003, New syntheses and new species in the Australian Ascidiacea, Journal of Natural History 37 (13), pp. 1611-1653 : 1639-1640

Ecteinascidia sluiteri Herdman, 1906

(figure 7A, B) Ecteinascidia sluiteri Herdman, 1906: 300 ; Tokioka, 1950: 126; Millar, 1975: 267; Nishikawa,

1984: 125; Monniot, 1992: 7; 1994: 229; 1997b: 566; Kott, 1985: 98 (part, not QM GH2034

= E. diaphanis ). Ecteinascidia vitta: Monniot, 1992: 7 .

Distribution. Mozambique, Gulf of Manaar, Singapore, Micronesia, New Caledonia, Palau Is, Coral Sea Plateau, northern Great Barrier Reef.

Description. The apparent length of the siphons and the shape of the gut loop vary, respectively, with contraction of siphonal muscles and with the width (degree of contraction) of the lateral and dorsal bands of parallel transverse muscles. The lateral bands are narrower when the zooid (and the gut loop) is more stretched out, and are wider when the thorax is wider and the gut loop more deeply curved.

Zooids are robust, albeit with thin, delicate, transparent test, thicker around the apertures. These sometimes protrude on siphons as shown in Herdman (1906: plate I (6)), E. sluiteri: Monniot, 1992 (figure 2) and E. vitta Monniot, 1992 (figure 3), or they are on less prominent siphons withdrawn into the test. The stomach is relatively small. The ovary is a variable distance dorsal to the arc of testis follicles.

Remarks. Despite its sympatric occurrence on the Coral Reef Plateau with E. sluiteri, Monniot (1992) separated one immature specimen lot as E. vitta . The full range of variation in the course of the gut loop, the branching of the gonads and the length of the external siphons that include the conditions said to separate these species occur even in the one colony, although these were not all recorded by Kott (1985) for E. sluiteri . It is difficult to understand how E. vitta , which occurs within the geographic range of E. sluiteri and differs only marginally from it, was not more closely scrutinized as possibly conspecific.