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Comprehensive Description

provided by Smithsonian Contributions to Zoology
Hyperietta stephenseni

DERIVATION OF NAME.–The species is named for the distinguished Danish carcinologist, Knut Stephensen.

TYPES.–All from CalCOFI Cruise 5, station 801, 13 July 1949, off southern California, 33°19′N, 120°45′W, oblique tow from 71 m to surface. Holotype, ♀, USNM 137507, allotype ♂. USNM 137508, 3♀ and 2 immature ♂ paratypes USNM 137509; 2♀ paratypes deposited at Scripps Institution of Oceanography.

DIAGNOSIS.–Length of ♀ about 2 mm, of ♂ 3–3.5 mm. Head about twice as high as long, evenly rounded ventrally. ♀ Al reaching ventral margin of head. Gland cone barely reaching ventral margin of head, broadly rounded, separated from epistome by short gap in lateral view. Lacinia of left Md with about 7 teeth. Mxp like that of H. luzoni; outer lobe about ¼ longer than wide, bearing a few spinules on both surfaces near distal margin. S2 of P1 about 2.2 times as long as wide, anterior margin convex in proximal 2/3, concave in distal ⅓; s5 bearing a single spine at midlength of posterior margin and 3 at posterodistal corner; s6 about 3 times as long as wide, bearing a single spine on anterior margin in ♀ 1–2 spines in ♂. S6 of P2 with a single spine on anterior margin in ♀, 1–2 spines in ♂. P6 very slightly longer than P5 and P7; s2 slightly wider in P5 than in P6–7, anterior margin convex and unarmed in P5, nearly straight and bearing 1 spine in ♀ 2 spines in ♂ in P6–7; s4–5 of ♀ with long spines at anterodistal corners; s4–5 of ♂ with shorter anterodistal spine and additional short spines on anterior margins. Telson slightly shorter than width at base, slightly more than half length of Up3 protopod.

DISTRIBUTION.–Warmer parts of the Atlantic, Pacific, and Indian Oceans. In the CalCOFI area its distribution is similar to that of H. stebbingi and the much more abundant Lestrigonus schizogeneios. It seems likely that H. stephenseni, like the latter two species, inhabits the transition zone.
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bibliographic citation
Bowman, Thomas E. 1973. "Pelagic amphipods of the genus Hyperia and closely related genera (Hyperiidea: Hyperiidae)." Smithsonian Contributions to Zoology. 1-76. https://doi.org/10.5479/si.00810282.136