Lestrigonus crucipes (Bovallius 1889)

Lestrigonus crucipes (Bovallius)

Hyperia crucipes Bovallius, 1889:225–228, pl. 11: fig. 14–25.–Walker, 1904:236.–Stephensen, 1924:90.–Barnard, 1937:184.–Pirlot, 1939:36.–Laval, 1968:64–65, fig. 12.–Dick, 1970:55.

DERIVATION OF NAME.–From the Latin “cruris” [=across] + “pes” [=foot], referring to spine overriding dactyl on P5–7.

TYPE-LOCALITY.–“The tropical region of the Atlantic: off Barbadoes.”

DIAGNOSIS.–Length about 4 mm. Body rather plump and compact. Pereonites 1–2 fused in ♂, 1–3 in ♀. Pleonal epimera with rounded posterior corners. A1–2 of ♀ well developed for a Lestrigonus; gland cone obtuse, projecting obliquely anteriad. Md with broad molar; incisors with 8–9 teeth. Mx1 inner lobes with 5 apical spines. Mx2 with 2 and 1 spines on outer and inner lobes respectively. P1–2 with 3–4 spines on anterior margin of s6; carpal process of P2 reaching beyond midlength of s6; s7 of P1–2 with spinulose posterior margin. P3–4 longer than P5–7; s4–5 with 2–3 spines on posterior margin; s6 posterior margin armed with close-set spinules. P5–7 with broad s2 and rather robust s3–6; s6 produced distally into recurved hook with 1–2 spiniform teeth on convex margin; hook overlaps s7 medially. Up1–3 with slender peduncles and rami. Telson oval, slightly wider than long, about 0.4 the length of Up3 peduncle.

RELATIONSHIPS.–The specimens that I have examined, all from the Arabian Sea, differ from Bovallius’ description so much that I was at first convinced that I was dealing with an undescribed species. But no specimens agreeing more nearly with Bovallius’ account have come to hand, and the frustrations of trying to reconcile the species descriptions of Bovallius with the characters that can be seen on his species have led me to share the opinion of Bovallius’ work expressed by Stephensen (1924), who wrote in evident exasperation, “… but in consideration of several positive misstatements in the work of Bovallius, there is hardly any reason to pay much attention to his remarks …” I am therefore assuming considerable error in Bovallius’ account of Hyperia crucipes. The principal discrepancies between Bovallius’ description and the specimens that I have examined are the following:

My disbelief in Bovallius’ accuracy was reinforced by examination of a female amphipod in the collections of the Stockholm Museum from the Caribbean Sea east of Dominica (15°22′N, 62°41′W). This specimen, labeled Hyperia crucipes var, macropis by Bovallius (an unpublished varietal name), agrees closely with the IIOE specimens. I have also examined Stephensen’s (1924) specimens from Thor stations 266, 377, and 399; they also closely resemble the IIOE specimens.

DISTRIBUTION.–Warm regions of the Atlantic (Bovallius, Pirlot, Laval, Stephensen) and Indian (Walker, Barnard) Oceans. The few specimens that I have examined were collected at three stations in the Arabian Sea during the International Indian Ocean Expeditions.