Lissosabinea beresfordi Taylor & Collins, 2009, sp. nov

Lissosabinea beresfordi sp. nov

Figures 1–2, 8.

Type material. Holotype. Australia, Southern Ocean, south of Tasmania, Huon 400 site (43°59.5' S, 147°32.76' E – 43°59.7' S, 147°33.80' E), 370–410 m, 31 Mar 2007 (stn SS02-2007 06), NMV J57989 (male specimen, cl. 7.0 mm).

Etymology. Named for Museum Victoria Principal Curator, Gary Charles Beresford Poore, in gratitude of the opportunities and guidance he has provided the authors.

Type locality. Tasmania, Australia, 370–410 m.

Distribution. Known only from type location.

Description. Based on holotype male.

Rostrum slightly descending, directed forward, laterally compressed, falling just short of distal margin of first segment of antennular peduncle; distal part blunt, broadened with ventral blade; dorsal surface with low, blunt median ridge without setae; lateral tooth strong arising from 0.40 of rostrum; ventral margin straight, unarmed.

Carapace 1.30 times as long as wide. Middorsal carina sharp, extending nearly to posterodorsal margin of carapace, armed with two large teeth; epigastric tooth falling far short of base of rostrum arising at 0.22 of carapace length; second tooth equal in size to the first, arising from 0.57 of carapace length. Dorsal surface of carapace without setae. Antennal tooth small, not reaching anterior margin of cornea of eye. Branchiostegal tooth directed forward, falling short of anterior margin of antennal basicerite. Pterygostomian angle without tooth. Lateral face of carapace with relatively large hepatic and one post hepatic tooth, but epibranchial tooth absent; epibranchial carina conspicuous.

Sternal tooth on fifth thoracic somite well developed in male, extending beyond base of spur on fourth somite.

Second abdominal somite smooth on dorsal surface. Third somite with middorsal carina in posterior 0.52; posterodorsal margin of somite strongly produced posteriorly, partially covering fourth somite. Sixth somite about 1.80 times as long as high; dorsal surface flat on midline. Telson with two pairs of minute dorsolateral spines; posterolateral angle with one short blunt spine and two pairs of longer spines (broken); terminal process tapered, tip rounded.

Antennular peduncle reaching 0.50 of antennal scale; stylocerite reaching nearly distal margin of first segment, spiniform. Antennal scale about 0.67 of carapace length and 3.30 times as long as wide, lateral margin slightly curved, distal blade rounded; basicerite with ventrolateral spine reaching mid length of first segment of antennular peduncle.

Mouthparts not dissected.

First pereopod with palm about 4.35 times as long as wide; cutting edge of palm strongly oblique; pollex relatively large, triangular, slightly recurved; carpus armed with one moderately large spine on lateral margin; merus with strong dorsodistal spine not reaching distal margin of anteriorly extended carpus, distolateral margin without tooth; ventral lamina terminating distally in small blunt tooth. Second pereopod falling far short of midlength of merus of first pereopod; dactylus about 0.44 length of propodus; propodus not widened distally. Third pereopod slender; ischium about 2.00 times as long as merus. Fourth pereopod moderately slender, overreaching antennal scale by length of dactylus and 0.30 of propodus; dactylus compressed laterally, about 0.37 times as long as propodus, propodus with distal tuft of setae; carpus 0.66 times as long as propodus; merus about ten times as long as wide, unarmed on dorsodistal margin; ischium 0.58 times as long as merus. Fifth pereopod similar to fourth, overreaching antennal scale by length of dactylus and 0.60 of propodus; ischium 0.44 times as long as merus.

Colour. Pereopods, ventral half of carapace and ventral third of abdominal somites pigmented red. Rostrum, dorsal carapace, first and sixth somites and telson green pigmented in life.

Remarks. All species of Lissosabinea recorded from Australia bear two median teeth on the carapace, a trait shared with congeners L. ecarina and L. indica, both known from Indonesian and now Australian waters. L. beresfordi shares the relatively blunt, deep rostrum with L. arthuri and to a lesser extent with L. lynseyae, the rostrum of which is less broad and spiniform distally. L. beresfordi is easily differentiated from L. arthuri by the shape of the third abdominal somite and the difference in the ventral lamina on the merus of first pereopod that terminates distally in a small blunt tooth as opposed to the prominent subacute tooth in L. arthuri. Also, the two median teeth on the carapace are of equal size and elevation in L. beresfordi but are unequal in L. arthuri.