Aega kwazulu, Bruce, 2004

Bruce, Niel L., 2004, Reassessment of the isopod crustacean Aega deshaysiana (Milne Edwards, 1840) (Cymothoida: Aegidae): a worldwide complex of 21 species, Zoological Journal of the Linnean Society 142 (2), pp. 135-232 : 187

AEGA KWAZULU SP. NOV. ( FIGS 33 , 34 , 62 )

Aega antillensis – Barnard, 1925: 389; Kensley, 1978: 57, figs 24A, B; 2001: 226 (part).

Aega deshaysiana – Nierstrasz, 1931: 182 (part).

Holotype: ♂ (33 mm), Natal coast, South Africa, ‘ex South Afr. Mus. ’ (BMNH, 1937.11.10.16).

Paratypes: ♀ (non-ovig. 32 mm), same data as holotype (BMNH, 1937.11.10.17) . ♂ (39 mm), off Umvoti River , 1923, c. 237 m, coll. H.W. Bell-Marly on S.S. Meikle (SAfM A6597) ( Barnard, 1925; this location is approximately 29∞22¢S, 31∞17¢E, in the general vicinity of Durban) ♀ (non-ovig. 47.0 mm), no locality, poor condition (SAfM A8080).

Description

Body 2.6 times as long as greatest width, dorsal surfaces smooth or sparsely punctate, widest at pereonite 5, lateral margins ovate. Rostral point projecting anteriorly, not ventrally folded. Eyes large, medially united, anterior clear field 11% length of head, posterior clear field 47% length of head; each eye made up of ~21 transverse rows of ommatidia, each row with ~9 ommatidia; eye colour dark brown (some specimens faded). Pereonite 1 and coxae 2–3 each with posteroventral angle rounded; coxae 5–7 with entire oblique carina. Pleon with pleonite 1 visible in dorsal view; pleonite 4 with posterolateral margins extending clearly beyond posterior margin of pleonite 5; pleonite 5 with posterolateral angles overlapped by lateral margins of pleonite 4. Pleotelson 1.2 times as long as anterior width, dorsal surface without longitudinal carina; lateral margins straight, smooth, posterior margin with elongate medial point.

Antennule peduncle articles 1 and 2 flattened, article 2 without anterodistal lobe; flagellum with 9 articles, extending to posterior margin of eye. Antenna peduncle article 2 inferior surface with distinct longitudinal suture; without deep longitudinal groove; article 5 not markedly wider or flatter than article 4; flagellum with 17 articles, extending to posterior of pereonite 2.

Frontal lamina flat, as wide as long, lateral margins parallel, anterior margin rounded (subtruncate), without small median point, posterior margin not abutting clypeus.

Pereopod 1 basis 2.2 times as long as greatest width; ischium 0.5¥ L basis, inferior margin with 0 RS, superior distal margin with 1 RS; merus inferior margin with 4 RS, set as 2 groups (of 2 and 2), superior distal angle with 1 RS; carpus 0.5¥ L merus, inferior margin with 0 RS; propodus 1.3 times as long as proximal width, inferior margin with 0 RS, propodal palm with simple, without blade or process, dactylus smoothly curved, 1.3¥ L propodus. P2 ischium inferior margin with 1 RS, superior distal margin with 1 RS; merus inferior margin with 5 RS, set as single row, superior distal margin with 1 acute RS; carpus similar in size to that of P1, inferodistal angle with 0 RS, propodus without large club-shaped distal RS. P3 similar to P2; propodus without large club-shaped distal RS. P6 similar to P7. P7 basis 3 times as long as greatest width; ischium 0.6¥ L basis, inferior margin with 5 RS (set as 1, 1 and 3), superior distal angle with 4 RS, inferior distal angle with 6 RS; merus 0.7¥ L ischium, 1.6¥ LW, inferior margin with 6 RS (set as 3 and 3), superior distal angle with 5 RS, inferior distal angle with 6 RS; carpus 0.9¥ L ischium, 2.9¥ LW, inferior margin with 2 RS (set as 1 and 2), superior distal angle with 3 RS, inferior distal angle with 7 RS; propodus 0.8 L ischium, 4.7¥ LW, inferior margin with 1 RS, superior distal angle with 2 slender setae (simple), inferior distal angle with 3 RS.

Penes opening flush with surface of sternite 7; penial openings separated by 9% of sternal width.

Pleopod 1 exopod 1.7¥ LW, distally narrowly rounded with strongly oblique medial margin, lateral margin distally concave (weakly), medial margin strongly convex, with PMS from base; distally rounded, lateral margin strongly concave, with PMS from distal one-third, medial margin with PMS from distal half; peduncle 1.7¥ WL, medial margin with 10 coupling hooks. Pleopod 2 appendix masculina with straight margins, 0.8¥ L endopod, distally bluntly rounded. Exopods of pleopods 1–5 each with distolateral margin not deeply serrate; endopods of pleopods 3–5 each with mediodistal point; pleopods 2–5 peduncle distolateral margin without prominent acute RS.

Uropod peduncle ventrolateral margin with 1 RS, posterior lobe about one-half L endopod. Uropod rami not coplanar, exopod at angle of about 135∞ to endopod, rami not extending beyond pleotelson, marginal setae in single tier, apices narrowly rounded. Endopod apically not bifid, lateral margin straight, with prominent excision positioned about three-quarters along ramus, proximal lateral margin with 3 RS, distal lateral margin with 4 RS, medial margin weakly convex, with 4 RS. Exopod not extending to end of endopod, 2.8 times as long as greatest width, apically not bifid; lateral

Figures

Figure 33. Aega kwazulu sp. nov. A–D, F, holotype, remainder female paratype, 32 mm. A, dorsal view. B, lateral view. C, head, dorsal view. D, frons. E, frons, female. G–I, pereopods 1, 2 and 7, respectively.

Figure 34. Aega kwazulu sp. nov. A, B, holotype, C, D, female paratype, 32 mm. A, pleopod 1. B, pleopod 2. C, uropod. D, uropod exopod, ventral view.

Figure 62. Distributions of: Aega alazon sp. nov. (•), A. excisa (Δ), A. japonica sp. nov. (*), A. kwazulu sp. nov. (-) and six undescribed species of the A. deshaysiana group (O).