dcsimg

Description

provided by NMNH Antarctic Invertebrates

"Cyathura profunda n. sp.

FIGURES 3-5; PLATES 1-3

DESCRIPTION.- Ovigerous Female: Integument in­durate, bearing numerous tiny spinose tubercles. Body proportions: C < 1 = 2 > 3 < 4 > 5 >6 > 7. Cephalon, pereon, and pleon with shallow irregular grooves. Cephalon with rostrum and anterolateral lobes demarked by strong groove; eyes lacking. Pleonites 1-5 fused, segments indi­cated by short epimera and interrupted irregular dorsolateral grooves; pleonite 6 lacking free lat­eral margins, with strong middorsal slit in poste­rior margin, fused to telson middorsally. Telson with margins gently tapering to broadly rounded apex, with low rounded middorsal ridge becom­ing obsolete in distal third; proximolateral hol­lowed area adjoining pleonite 6; statocyst open­ings narrow, situated at base of middorsal ridge.

Antennule with basal segment subequal to three distal peduncular segments together; fourth segment very short; flagellum of three articles, two distal setose articles very small. Antenna with second peduncle segment grooved to accommo­date antennule; flagellum of single short setose article. Mandibular palp 3-segmented, middle segment longest, distal segment bearing row of 12 fringed spines; molar low, bluntly rounded; inci­sor of three strong cusps; lamina dentata of 11 serrations. Maxilla of single large and six smaller spines. Maxilliped 4-segmented, fourth segment small, oval, set obliquely at distolateral corner of third segment, with four setae on medial margin; third segment with four short mediodistal setae; second and third segments subequal in length. Pereopod 1 subchelate, propodus expanded, pal-mar margin straight, with low rounded proximal convexity, with row of 11 or 12 simple setae; inner surface with 17 to 20 setae. Pereopods 2-7 essen­tially similar; propodi elongate-linear, carpi tri­angular, with very short anterior margin, under-riding propodus. Marsupium of three pairs of oostegites on pereonites 3-5. Pleopod 1 exopod operculiform, indurate, with low rounded proxi­mal ridge, tapering strongly in distal half; exo­pods of left and right side overlapping in midline, especially distally; endopod half width and about three-quarters length of exopod. Uropodal exo­pod reaching level of telsonic apex, broadly oval, distally subacute, outer margin faintly sinuous; basis almost reaching telsonic apex, parallel-sided in dorsal view, triquetrous with strong ventral ridge; endopod oval-rounded, extending beyond telsonic apex.

Male: Anterior body essentially similar to fe­male; pleon relatively more elongate. Antennule with dense clusters of aesthetascs on third flagellar article. Pereopod 1 propodus with about 40 setae on inner surface. Pleopod 2 with copulatory stylet extending about half its length beyond endopod, distally evenly rounded."

(Kensley, 1982: 4-12)