Styloptocuma poorei, Petrescu, 2006

Petrescu, Iorgu, 2006, Nannastacidae (Crustacea: Cumacea) from eastern Bass Strait, the south-eastern Australian slope, and Antarctica in the collections of Museum Victoria, Memoirs of Museum Victoria 63 (2), pp. 129-173 : 167-168

Styloptocuma poorei sp. nov.

Figure 61

Material examined. Holotype female, Tas., off Freycinet Peninsula, 42°00.20'S, 148°37.70'E, 720 m, coarse shelly sand, WHOI epibenthic sled, M.F. Gomon et al., RV Franklin, 27 Jul 1986 (stn SLOPE 46 ), NMV J53068.

Diagnosis.Carapacewithshort,littleupturnedpseudorostrum, with several dorsal spines and strongly serrated lower margin. Short serration on pleonite 5. Propodus of maxilliped 3 as long as ischium, merus and carpus combined. Carpus of pereopod 1 longer than propodus. Dactylus of pereopod 2 3.8 times as long as propodus. Uropod peduncle with serrated inner margin, 2.9 times as long as pleonite 6 and 1.3 times as long as endopod, endopod twice as long as exopod, with 1 seta on inner serrated margin.

Description. Body with weakly calcified smooth integument. Length: 2.8 mm.

Carapace 0.31 body length, 1.4 times as long as high, short pseudorostrum (0.18 carapace length), 7 dorsal median spines, 1 near posterior extremity, first 2 on frontal lobe, antennal notch not marked, lower margin strongly serrated.

Antenna 1 basal article of peduncle little longer than other 2 articles combined, median article with small tubercle, main flagellum longer than last article of peduncle, accessory flagellum minute, uniarticulate.

Maxilliped 3 basis less than half as long as appendage, 2 long plumose setae on outer distal corner, a tooth and a plumose seta on outer margin of merus and carpus, propodus 2nd longest article, as long as ischium, merus and carpus combined, dactylus with stout terminal curved seta, longer than dactylus.

Pereopod 1 basis less than half as long as appendage, carpus longer than propodus. Pereopod 2 basis less than half as long as appendage, carpus twice as long as merus, with 2 stout spines on distal inner corner of carpus, dactylus 3 times as long as propodus, with a stout terminal seta longer than dactylus. Pereopods 3–5 with progressively shorter basis and longer carpus (3.4 times longer carpus than merus in 5th pair), dactylus fused with its terminal seta. Exopods on maxilliped 3 and pereopods 1, 2.

Uropod peduncle with a serrated inner margin, 2.9 times as long as pleonite 6 and 1.3 times as long as endopod, endopod twice as long as exopod, with 1 subterminal seta on inner serrated margin.

Etymology. The species is dedicated to Gary Poore, Principal Curator, Museum Victoria, Melbourne, Australia, well known specialist in Peracarida, as a sign of gratitude.

Distribution. Off Freycinet Peninsula, Tas.; 720 m depth.

Remarks. The new species differs from other species of Styloptocuma in this collection in the carapace with a few dorsal spines, a strongly serrated entire lower margin, lacking a lateral row of spines and a relatively smooth pereon and pleon. Such a combination of characters may also be found in S. subductum Jones, 1984 from the Atlantic but that species has the lower margin of its carapace serrated only on the anterior half and the uropod endopod has four setae on the inner margin instead of one as in Styloptocuma poorei .

Figures

Figure 61. Styloptocuma poorei sp. nov. female holotype: a, body, lateral view; b, antenna 1; c, maxilliped 3; d, pereopod 1; e, pereopod 2; f, pereopod 3; g, pereopod 4; h, pereopod 5; i, pleonite 6 and left uropod. Scale (in mm): a, 0.5; b, 0.2; c, 0.1; d–i, 0.25.