Vibilia longicarpus Behning, 1913

Zeidler, Wolfgang, 2003, A review of the hyperiidean amphipod superfamily Vibilioidea Bowman and Gruner, 1973 (Crustacea: Amphipoda: Hyperiidea), Zootaxa 280 (1), pp. 1-104 : 60-63

Vibilia longicarpus Behning ( Figs 27 & 28 )

Vibilia longicarpus Behning, 1913a: 530–533 , figs 2­6. — Behning 1913b: 222. Semenova 1973.

174–175, fig. 3. Vinogradov et al. 1982: 230–232, fig. 114. Shih & Chen 1995: 57–58, fig. 32. Vibilia pyripes [misidentification — in part]. — Zeidler 1998: 34 (SAMA C4420, 4422, 4423).

Type material

Six syntypes of V. longicarpus are in the ZMB (20922). The type locality is the eastern mid­Pacific Ocean. Behning (1913a) does not specify a holotype, or the number of specimens examined. He illustrates a female from Albatross Stn. 4709 (10º15’12”S, 95º40’48”W), and a male from “Alb. 4.ix.1899 ”, which is presumably near the preceding locality but is not Stn. 4710 judging by the data.

Material examined (41 specimens)

Types. Six syntypes of V. longicarpus from Albatross Stn. 4709 30 th December 1904 and Stn. 4710: all in spirit; the female from Stn. 4709 is dissected on the left and has the Us missing. The specimens from Stn. 4710 are juveniles that could not be determined as this species with confidence.

Other material examined. North Atlantic: 1 lot ( ZMH), 1 specimen . North Pacific : 2 lots ( USNM), 2 specimens . Central Indo­Pacific : 1 lot ( USNM), 1 specimen . Tasman Sea : 3 lots ( SAMA), 3 juv. specimens. Arabian Sea : 2 lots ( BMNH), 28 specimens .

Diagnosis

Body length up to 12 mm. Antennae 1 as long as head and first pereonite; flagellum elongate, oval, ventral margin the more convex. Gnathopod 2; carpal process as long as, or slightly longer than, propodus. Pereopods 3 & 4; dactylus length about 0.3x propodus. Pereopods 5 & 6; dactylus length about 0.3x propodus. Pereopod 7; basis narrowed proximally, maximum width about 0.7x length, about as long as ischium to carpus combined, with relatively large rounded posterodistal lobe extending well past the ischium; carpus and propodus with small anterodistal process. Lateral corners of last urosomite produced, partly overlapping peduncle of U3. Uropod 3; peduncle subequal in length to rami; endopod subequal in length to exopod in females, in males the endopod is slightly broader and longer. Telson almost circular, length about 0.7x peduncle of U3.

Remarks

This species most closely resembles V. cultripes , but is distinguished by the longer carpal process of gnathopod 2, and the much smaller anterodistal processes on pereopod 7. Also the dactylus of pereopod 7 is rounded and not knife­shaped. In the shape of the urosome it is similar to V. pyripes .

There are three specimens from the Tasman Sea ( SAMA C4420, 4422, 4423), which had been identified as V. pyripes ( Zeidler 1998) , which are now considered to be this species. They all appear to be juveniles measuring 4 mm or less. In the shape of the first antennae, pereopods 3 and 4, and the telson they resemble V. longicarpus , but in the shape of pereopod 7 and the peduncle of uropod 3 they resemble V. armata ( Figs 12 & 13 ). The dactylus of pereopods 3–6 is also slightly longer than is usual for V. longicarpus , but this is probably a juvenile character.

The salp associate has not been recorded for this species.

Distribution

This is a rare species, found only in the tropical parts of the eastern Pacific Ocean, South China Sea and the northwestern part of the Indian Ocean.

Figures

FIGURE 12. Vibilia armata, Tasman Sea, SAMA C4391. A, male 8.3 mm, lateral view; B, female 9.1 mm, lateral view of head; appendages from male except Us­f. Scale bars = 1.0 mm (A, B), 0.5 mm (Us), 0.2 mm (A1 & 2).

FIGURE 13. Vibilia armata, Tasman Sea, SAMA C4391. Male 8.3 mm. Scale bar = 0.5 mm.

FIGURE 27. Vibilia longicarpus, Tasman Sea, SAMA C4422. Female (?), 4.2 mm. A, lateral view. Scale bars = 1.0 mm (A), 0.1 mm (Mxp), 0.2 mm (remainder).

FIGURE 28. Vibilia longicarpus, Tasman Sea, SAMA C4422. Female (?), 4.2 mm. Scale bar = 0.2 mm.