Deep-Water Crustacea of the Genus Sergestes (Decapoda, Natantia) from Cook Strait, New Zealand
A large, fragile shrimp with small eyes and a soft and membraneous integument.
Rostrum relatively small and obtuse, hardly projecting beyond the anterolateral margin of the carapace and little raised above the dorsal surface of the latter. Supraorbital and hepatic spines absent. Cervical groove distinct and continuous over dorsum, weak anterolateral ridge from hepatic region towards base of antenna, suprabranchial ridge present.
Eyes relatively small, cornea barely wider than and about one-third as long as distal segment of ocular peduncle. No ocular tubercle. Segments of antennular peduncle not greatly attenuated, proximal longer than second, which is subequal to third. No distolateral spine on margin of scaphocerite. Third maxillipeds not greatly enlarged, subequal in length to 2nd or 3rd pereiopods.
Male with petasma as shown (Figs. 8, 9); lobus connectens very long, armed on lateral margin and distally on inner margin with crochets; processus ventralis shorter, with distinct distal nick; lobus armatus curved, shorter than processus ventralis, but reaching a little beyond lobus inermis, armed on inner margin with small crochets; lobus terminalis a simple armed projection, smaller than the unarmed lobus inermis, between the latter and the base of the lobus connectens.
Female with single blunt posteromedial projection on coxa of 3rd pereiopod.