Vibilia caeca Bulycheva, 1955

SHIH, CHANG-TAI & HENDRYCKS, ED A., 2003, A new species and new records of the genus Vibilia Milne Edwards, 1830 (Amphipoda: Hyperiidea: Vibiliidae) occurring in the eastern Pacific Ocean, Journal of Natural History 37 (3), pp. 253-296 : 285-288

Vibilia caeca Bulycheva, 1955

( figures 14 , 15 )

Vibilia caeca Bulycheva, 1955: 1050 . Vinogradov, 1956: 208–209, figure 7 .

Material examined. See table 3.

Description of female. Head length three-quarters height, slightly shorter than pereonites 1–2 combined, nearly rectangular when viewed laterally. Rostrum about two-thirds as long as remainder of head and bent downward, ventrally marked with a shallow sinus. Eyes absent. Antenna 1 length equal to combined length of head, pereonites 1–2, and one-half of pereonite 3; flagellum length 2.8 times that of peduncle, five times height, inferior profile straight in proximal half and tapering in distal half. Upper lip weakly incised, asymmetric. Mandible with left lacinia mobilis nearly as wide as incisor, bearing eight or nine teeth on distal margin; right lacinia mobilis narrow and drumstick-like, about one-third as wide as incisor, with fine denticles on distal margin; accessory spine row with five or six short spines; molar small, columnar, trituritive; palp long, third segment straight, acutely tipped, longer than first and second segments combined, with a single row of fine setae. Maxilla 1 with six spine teeth on distal margin of outer plate, palp uniarticulate, strongly narrowing distally with one spine at tip. Maxilla 2 with inner and outer plates nearly totally fused, apically setose. Maxilliped outer lobes oval-shaped, length about twice width, strongly toothed on proximal two-thirds of inner margin, outer margin smooth with two or three fine setae.

Pereon 1.5 times as long as pleon, height increasing posteriorly, pereonite 7 about 1.5 times as high as pereonite 1. Coxae increasing in length from pereonite 1 to 5 then decreasing to 7, ventral margin of coxae 5 and 6 with a notch in midlength. Pereopod 1 simple, anterior margin of basis slightly convex at proximal third; propus subrectangular, with posterior margin palm-like, finely setulate and distal margin as wide as dactyl. Pereopod 2 chelate, carpal process reaching slightly beyond distal margin of propus, anterior margin with strong and wide serrations, distal two-thirds of posterior margin of propus finely serrated. Pereopod 5 about 1.3 times as long as pereopod 3, basis 1.2 times as long as ischium and merus combined, propus 0.8 times as long as merus and carpus combined, and 0.9 times as long as basis. Pereopod 6 carpus, anterior margin lacking spines. Pereopod 7 with complete segmentation, basis narrow, about 0.5 times as wide as long, 0.5 times as long as ischium to dactyl combined, posterodistal lobe reaching distal margin of ischium, carpus and propus not produced at anterodistal corner; dactyl length one-half propus, dactyl pointed without scales.

Pleon about three times as long as urosome, pleonites 1–3 subequal in length. Posterodistal corner of pleonites 1 and 2 roundly angular; pleonite 3 with angular posterodistal corner and sigmoid ventral margin.

Urosomites 2 and 3 fused, laterodistal corners not produced. Uropod 1 protopod 1.3 times as long as exopod, distal half of outer margin on protopod and both margins of exopod and endopod strongly toothed. Uropod 2 endopod with one small tooth on outer margin. Uropod 3 protopod length 2.4 times width and 1.6 times length of exopod, endopod outer margin with very fine serrations; exopod inner margin with very fine serrations. Telson separate from double urosomite, triangular, slightly longer than broad (1.2 times as long as broad in male).

Size. Female: 2.98–6.20 mm; male: 5.20–6.30 mm.

Distribution. Pacific Ocean: Bering Sea; Kuril-Kamchatka. This is the first record of the species in the eastern Pacific Ocean. In the present study it was found in 11 samples from 1070 to 1300 m off California (33°11∞–33°27∞N, 118°29∞–118°54∞W) and in two samples from 100 to 900 m from the Gulf of Alaska (53°52∞N, 158°29∞S and 55°35∞N, 139°06∞W). Our records off California have significantly extended the southern distributional range of Vibilia caeca .

Figures

FIG. 14. Vibilia caeca Bulycheva, 1955. Female, 4.9 mm, IPHC station 930-296C. Male, 4.9 mm, COFF station 54-8711. Appendages, if unspecified with sex, belong to the female. Scale bars=0.1 mm unless otherwise indicated.

FIG. 15. Vibilia caeca Bulycheva, 1955. Appendages of the female (4.9 mm) and male (4.9 mm) of figure 14. Appendages, if unspecified with sex, belong to the female. Scale bars=0.1 mm.

FIG. 7. Vibilia cultripes Vosseler, 1901. Mouthparts, uropods and telson of male (12.0 mm) of figure 5. Scale bars=0.1 mm.