Elasmopus levis S.I. Smith, 1873

Vader, Wim & Krapp-Schickel, Traudl, 2012, On some maerid and melitid material (Crustacea: Amphipoda) collected by the Hourglass Cruises (Florida). Part 2: Genera Dulichiella and Elasmopus, with a key to world Elasmopus, Journal of Natural History 46 (19 - 20), pp. 1179-1218 : 1181-1185

Elasmopus levis S.I. Smith, 1873

( Figures 1–3 )

S.I. Smith 1873: 559; Paulmier 1905: 162, fig. 32; Bousfield, 1973: 63-64, pl. X/2; Feeley and Wass 1971: 15; LeCroy 2000: 87.

Material examined

45166 (EJ 67074) Hillsborough County; 19 miles (30 km) west of Egmont Key. 27 ◦ 37 ′ N, 83 ◦ 07 ′ W 18-m Dredge. 2 March 1967. One female .

14591 (EJ 72183) St Lucie County; east of F.P.& L. Electrical generating plant. 27 ◦ 22 ′ 08" N to 27 ◦ 22 ′ 08" N, 80 ◦ 13 ′ 46" W to 80 ◦ 13 ′ 46" W; 11.8 11.8 Shipek grab. Hutchinson Island Nuclear Power Plant Environmental Study. One male 9 mm, one female 8 mm dissected, 7 September 1972, slide FSBC I 79919; one female in alcohol .

Description

Length. 9–12 mm.

Head. A1 more than half body length, acc. flag. with two or three arts; A2 half or more than length of A1, flagellum with six to eight arts.

Mouthparts. Md palp art 2 ≤ art 3. Md palp art 3 l:b = 2.5–3. Md palp art 1 distally obliquely rounded, ratio art 1: art 2> half.

Pereon. Cx 1 anteroventral corner rounded. Gn1 palm almost transverse. Gn1 propodus facially near inner and outer margin setose. Gn2 dactylus strongly curved, ratio dactylus to propodus 1/2. Gn 2 male dactylus “comes across” the propodus. Gn2 palm not excavate, but shallow, wide depression, in male posterior margin setose. Gn 2 male ratio propodus:carpus = 4–5. Gn 2 female similar, but smaller, at palmar corner strong spines and no depression. Male pereopods: P3, 4 propodus distal spines normal. P5 basis broadened, convex. P5–7 basis hind margin with short setae, in P6, 7 serrate. Female pereopods less setose and less expanded.

Pleon. Ep3 posterodistal corner acute tooth, posterior margin smooth, concave, inferior margin with short spines. Urosome without bump. U1 peduncle with one basofacial seta. U3 ratio peduncle: longer ramus = 0.6–0.7. U3 rami ratio 1–1.25. Telson cleft, l ≥ b, halves distally deeply concave, with acute inner lobes longer than acute outer ones; two or three strong distal spines, shorter than telson length and not exceeding inner lobe.

Remarks

It is very strange that within the rich material of the Hourglass collection the presence of the two species has such an unequal numerical balance and none of the undescribed species of LeCroy 2000: 80 ff. could be found.

Figures

Figure 1. Elasmopus levis A1,2, antennae; Mx1, Mx2, maxillae; Md, mandible, slide FSBC I 79919.

Figure 2. Elasmopus levis Gn1, Gn2, gnathopods of both sexes, slide FSBC I 79919.

Figure 3. Elasmopus levis P3, P5, P6, P7, pereopods; Ep2, Ep3, epimeral plates; Us, urosome; U3, third uropod; T, telson; slide FSBC I 79919.