Eisothistos nowrae, Poore, Gary C. B., Lew, Helen M. & Ton, 2002

Poore, Gary C. B., Lew, Helen M. & Ton, 2002, Expanathuridae (Crustacea: Isopoda) from the Australian region, Zootaxa 82, pp. 1-60 : 19-21

Eisothistos nowrae n. sp. ( Fig. 12 )

Material examined.– Holotype. Australia. New South Wales, off Nowra (34°59.52'S, 151°5.94'E), 204 m, coarse shell, WHOI epibenthic sled, G.C.B. Poore et al. on RV Franklin, 14 Jul 1986 (stn SLOPE 1), NMV J17225 (juvenile, 3.9 mm, with 1 slide). Paratype. Type locality, NMV J17223 (manca, 1.5 mm).

Description: Juvenile. Body scarcely broader posteriorly; head and pereonite 1 about equal length, pereonite 3 as long as the two together, pereonites 4–7 progressively shorter, 7 about half as long as 6; pleonites 1–5 very short, together about as long as pereonite 7, with lateral plumose setae; pleon and pleotelson 0.28 body length.

Head with few scattered ommatidia, produced slightly beyond bases of antennae. Antenna 1 with article 1 longer than wide; article 2 about as long; article 3 1.2 times as long as 2; flagellum with article 1 longer than wide, 5 additional articles, progressively shorter, terminal 2 each with 1 aesthetasc. Antenna 2 peduncle longer than that of antenna 1, article 5 longer than all others together; flagellum of 6 articles.

Pereopodal coxal plates 1–7 moderately produced laterally. Pereopod 1 not subchelate; propodus 4 times as long as broad, with row of 3 mesial setae, simple seta distally on palm; dactylus as long as propodus and with setae posteriorly. Pereopods 2 and 3 longer and stronger than pereopod 1, ischium and merus each with rounded lobes along posterior margin; propodus with overlapping pectinate setae along palm and distal spiniform seta; dactylus with similar setae scattered on palm. Pereopods (4 lost) 5–7 more elongate than more anterior limbs; carpus–propodus with pectinate scales along posterior margins and spiniform seta distally; ischium with long plumose seta(e) on anterior margin.

Pleopod 1 with rami fused, distally with 6+5 plumose setae, finely setose on anterior face. Pleopod 2 endopod smaller than pleopod 1, with 3 plumose setae on rounded apex; exopod three­quarters length of endopod, narrow, with 4 distal and lateral plumose setae. Pleopods 3–5 similar to pleopod 2 but shorter.

Uropodal peduncle broadening distally, dorsolateral margin ending simply; endopod attached obliquely, lateral margin with obtuse proximal lobe, remainder of margin irregularly dentate, apex with short seta between longer marginal ones; exopod with narrow central spike with subapical short seta, outer lobe a simple triangle, inner lobe with serrate margin leading to spike. Telson waisted one­third along, broadest near posterior margin, margin obscurely dentate beyond widest point, apex almost truncate with irregular serrations, almost in pairs.

Adult male and female. Unknown.

Distribution: Australia, off southern New South Wales, continental shelf, 204 m depth.

Etymology: For Nowra, a town in New South Wales, near the type locality.

Remarks: The pattern of setation of the pereopods and arrangement of the uropods and telson are similar to E. victoriae n. sp. but this species differs in having more elongate limbs and uropodal rami. The mouthparts were not dissected.

Figures

FIGURE 12. Eisothistos nowrae n. sp. Holotype, NMV J 17225.