Comprehensive Description

provided by Smithsonian Contributions to Zoology
Atylus aberrantis J. L. Barnard, 1962:69, figs. 66, 67

DIAGNOSIS.–Pereonites 1–6 without teeth, pereonite 7 with rudimentary posterodorsal tooth, pleonites 1–3 with small tooth, pleonite 4 with medium tooth and weak anterior tooth separated by deep sinus from main tooth; body setae weak or absent; epimera 1–3 with strongly convex posterior margin, each with tiny posteroventral cusp, epimeron 2 without lateral row of setae, epimera 2–3 each with lateral ridge (also on epimeron 1 in certain specimens); rostrum short, thick, extending along 50 percent of article 1 on antenna 1, first cephalic tooth half as long as rostrum, second tooth half or a third as long as rostrum; mandibular palp article 3 as long as article 1, article 2 twice as long as article 3; anterior coxae short and broad, coxa 1 slightly slipper-shaped, as broad at apex as at base, not bifid, coxae 2–3 as long as coxa 1, broad and apically truncate, coxa 4 scarcely concave ventrally, coxa 5 with soft, minute anterior lobe, coxae 5–7 with rounded posteroventral corners; or pointed on coxa 7; accessory flagellum very short, as broad as long or 1.67 times as long as broad in male, 1-articulate; telson cleft two-thirds, lobes not gaping but appressed [artificially spread in figures], each apex with one small spine; uropod 1 ordinary; outer ramus of uropod 2 reaching 67 percent along inner ramus; inner ramus of uropod 3 slightly shorter than outer ramus; pereopods short.

DESCRIPTION.–Mouthparts as shown for Lepechinella occlo, new species, except as follows: NZOI-709, upper lip only slightly emarginate, inner plate of maxilla 1 with three setae, outer plate of maxilliped with six medial and five distal spines and setae; Vema 14–38, upper lip evenly rounded below, palp article 3 of mandible with three terminal setae and no middle seta, molar seta very long, inner lobes of lower lip smaller.

Vema 14–38: Article 2 of antenna 1 twice as long as article 1, article 3 half as long as article 1, flagellum broken; articles 4–5 of antenna 2 equal to each other in length, flagellum as long as articles 4–5 of peduncle; uropod 3 as in Lepechinella cachi, new species, including article 2 (also on NZOI E-709); differing from holotype in slight cusp on coxa 7, slightly larger tooth on epimera 1–3 and bevelment of coxae 3–4.

NZOI E709: Differing from holotype in longer first cephalic tooth but second tooth shorter than on holotype; dorsal teeth longer on pereonites 6–7 and pleonites 1–6; pleonite 6 bearing tooth; coxa 7 with sharp posteroventral tooth perhaps overlooked or damaged in type; presence of facial ridge on epimeron 1.

MATERIAL.–Vema 14–38 (female, 4.8 mm); NZOI E709 (male, 6.1 mm).

REMARKS.–This species is as close to Atylus as it is to the type-species of Lepechinella and is especially like Atylus in its head, accessory flagellum, coxae, dorsal teeth, short pereopods, and epimera, but unlike Atylus it bears inner lobes on the lower lip.

DISTRIBUTION.–South Africa, 4893 m; New Zealand, 1683 m; east of Madagascar, 1421–1750 m.
bibliographic citation
Barnard, J. L. 1973. "Deep-sea Amphipoda of the genus Lepechinella (Crustacea)." Smithsonian Contributions to Zoology. 1-31. https://doi.org/10.5479/si.00810282.133