Campylaspis rectangulata, 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 : 147-148

Campylaspis rectangulata sp. nov.

Figures 27 , 28

Material examined. Holotype immature male, NSW, off Nowra, 34°57.90'S, 151°08'E, 503 m, bryozoa and shell, WHOI epibenthic sled, G.C.B. Poore et al., RV Franklin, 14 Jul 1986 (stn SLOPE 2 ), NMV J54123.

Diagnosis. Carapace with large lateral sulcus, rectangular in dorsal view, with short thoracic and abdominal segments. Maxilliped 2 with short dactylar teeth, shorter than robust seta of propodus. Merus of maxilliped 3 with inner concavity, enlarged merus and carpus. Pereopod 1 with short articles (except enlarged merus), with numerous plumose setae. Dactylus of pereopod 2 without digitiform extremity. Uropod peduncle twice as long as pleonite 6 and 1.4 times as long as its equal rami, without setae, exopod with long robust terminal seta, endopod with 3 microserrate setae on inner margin and longer, more robust, terminal seta.

Description. Body with highly calcified smooth integument. Length: 3.5 mm.

Carapace 0.51 body length, covering first 4 pereonites in lateral view, 1.8 times as long as high, with large lateral sulcus (0.6 of carapace length, 3 times as long as high), frontal lobe with large base and small ocular lobe without eyes, antennal notch almost absent, anterolateral corner with short serration. Pleon elongated, 0.45 body length.

Antenna 1 peduncle with short and robust articles, with serrated margins, main flagellum 3-articulate, longer than distal article of peduncle, accessory flagellum tiny, uniarticulate.

Maxilliped 2 basis with strong plumose seta on inner margin, similar seta medially on distal margin of merus, carpus with 2 simple setae on inner margin, propodus second longest article, with robust curved seta on outer distal corner, longer than dactylar teeth, dactylus fused with 3 short, equal, teeth. Maxilliped 3 basis less than half as long as appendage, with serrated inner margin, with 2 plumose setae on inner distal corner and another 2 longer on outer distal corner, ischium with tooth and plumose seta on inner margin, merus second longest article, with inner concavity with setae, tooth and long plumose seta on outer margin, carpus enlarged, shorter than merus, with 2 teeth and 2 plumose setae on outer margin, propodus shorter than carpus, thinner, with 3 pappose setae on inner margin, dactylus 0.58 propodus length, with 3 long simple terminal setae.

Pereopod 1 basis less than half as long as appendage, with serrated margins (outer margin stronger), with 2 plumose setae on inner distal corner, short and robust articles with serrated margins and numerous plumose setae excepting dactylus with short simple ones, merus second longest article, carpus longer than propodus, propodus longer than dactylus. Pereopod 2 bulky, basis less than half as long as appendage, with serrated margins, short plumose seta on inner distal corner, 1 simple and 1 plumose seta on inner distal corner of merus, short carpus (1.5 times as long as merus), with short plumose seta on distal inner corner, dactylus 3 twice as long as propodus, with a right-angled extremity, with simple and plumose setae on margins, long stout terminal seta, shorter than dactylus. Pereopods 3–5: pair 3 and 4withenlargedbasis,progressivelyshorter,carpusprogressively longer (3 times as long as merus in 5th pair), dactylus with robust long terminal seta. Exopods, 5 pairs incompletely developed (characteristic of immature specimen).

Uropod peduncle twice as long as pleonite 6 and 1.4 times as long as equal rami, without setae, with serrated inner margin, exopod with long robust terminal seta, endopod with 3 microserrate setae on inner margin and longer, more robust, terminal seta.

Etymology. The name “ rectangulata ” describes the carapace in dorsal view, almost square.

Distribution. Off Nowra, NSW; 503 m depth.

Remarks. Campylaspis rectangulata is similar to C. anae (in the form of the carapace and similar antenna 1). It differs in having a maxilliped 2 with shorter teeth on the dactylus, a shorter robust distal seta on the propodus, merus of maxilliped 3 with an inner concavity and a stout seta (versus none) and shorter uropods with slender peduncle, longer subequal rami (versus exopod shorter than endopod in C. anae ), and three microserrate setae on the inner margin of the endopod instead of four. Pereopods are sexually dimorphic.

Figures

Figure 27.Campylaspis rectangulata sp. nov. female holotype: a, body, lateral view; b, carapace and pereon, dorsal view; c, antenna 1; d, maxilliped 2; e, maxilliped 3; f, pereopod 1. Scale (in mm): a, b, 0.5; c–e, 0.25; f, 0.5.

Figure 28. Campylaspis rectangulata sp. nov. female holotype: a, pereopod 2; b, pereopod 3; c, pereopod 4; d, pereopod 5; e, pleonite 6 and left uropod. Scale (in mm): a, 0.5; b–e, 0.25.