Barbascalpellum rossi, Young, 2001

Young, Paulo S., 2001, Deep-sea Cirripedia Thoracica (Crustacea) from the northeastern Atlantic collected by French expeditions, Zoosystema 23 (4), pp. 705-756 : 728-731

Barbascalpellum rossi n. sp.

( Figs 16 ; 17 )

TYPE MATERIAL. — Holotype 1, N. Ireland, PROS- PEC, stn CPH 10, 55°18.69’N, 10°14.83’W, 1589 m to 55°18.11’N, 10°15.38’W, 1578 m, 1600 m, tl (cl) 43.1 (26.6) mm (MNHN Ci 2867); paratypes, same locality, 6 specimens, tl (cl) 29.9 (18.9) to 49.4 (27.8) mm (MNHN Ci 2868, MNRJ 13911 ).

ETYMOLOGY. — Named in honor of my friend and spiritual mentor Arnold Ross.

DIAGNOSIS. — Scutum with lateral arm less than onethird length of tergal margin. Upper-latus pentagonal with subapical umbo. Inframedian-latus vase shaped, with umbo almost basal. Caudal appendage with five articles, length nearly equal to protopodite.

DESCRIPTION

Capitulum ( Fig. 16A ) oval, flattened, length less than twice width; growth lines thin and inconspicuous. Cuticle reddish, thick, sparsely pilose and with well-marked sutural plate scars.

Tergum ( Fig. 16A ) divided into two arms, with original surface area larger than that of scutum. Basal margin with deep concavity. Carinal margin slightly concave with lateral thickening near apex of carina. Occludent margin straight turning strongly convex in apical portion. Apex curved toward carina.

Scutum ( Fig. 16A ) convex, with short lateral arm, length less than one-third length of tergal margin; height more than twice greatest width. Basal margin slightly convex. Tergal margin nearly straight. Occludent margin convex. Apex not overlying on tergum.

Carina ( Fig. 16A, B ) regularly arched, with umbo situated at three-quarters of length. Tectum flat; lateral angulary bent; basal margin straight.

Upper-latus ( Fig. 16A ) nearly pentagonal with umbo subapical, slightly projecting above surface of capitulum. Tergal and scutal margins symmetrical, slightly concave; other margins having an irregular outline.

Carino-latus ( Fig. 16A, B ) higher than wide, with umbo basal, slightly projecting outward. Lateral margin having an irregular outline. Carino-latera not in contact with one another.

C

Inframedian-latus ( Fig. 16A ) vase shaped with umbo almost basal; umbo projecting outwards.

Rostro-latus ( Fig. 16A, C ) wider than high, width almost four times height, without apicobasal ridge. Upper margin slightly concave; lateral margin rounded.

Rostrum ( Fig. 16C ) absent.

Peduncle ( Fig. 16A ) little shorter than capitulum, covered sparsely by scales deeply immersed in cuticle. Scale whorl eight-plate pattern: rl-cl, sr-l-sc. Labrum ( Fig. 17A ) bullate, without teeth. Palp ( Fig. 17A, B ) elongated with several fine setae on apex and few small setae on inner margin. Mandible ( Fig. 17C ) with three teeth; lower angle denticulate, without setae. Maxilla I ( Fig. 17D ) small, with straight anterior border, and 11 large and smaller and unpaired spines. Maxilla II ( Fig. 17E ) squared; covered with numerous large and simple setae except for medi- an space on anterior margin and another on upper margin; papilla of maxillary gland pronounced.

Cirrus I ( Fig. 17F ) with anterior ramus twothirds length of posterior ramus; former with protuberant articles; both rami covered by numerous large, simple setae. Cirrus II to VI with equal rami. Median article of cirrus VI ( Fig. 17G ) almost two times longer than wide, four groups of setae on anterior margin, upper one with four setae, uniformly distributed small setae on lateral surface, scales and intercalated setae on posterior margin and three setae on posterior angle.

Caudal appendage ( Fig. 17H ) with five articles, nearly same length as protopodite of cirrus VI; articles with few, small setae on anterior margins, and cluster of pinnate setae on apex. Number of articles of cirri I-VI and caudal appendage is presented in Table 4.

REMARKS

Barbascalpellum rossi n. sp. is the first species of this genus recorded from the Atlantic Ocean. The genus is represented in the Pacific Ocean by B. sanctabarbarae (Pilsbry, 1907) from California and by B. cochlearium ( Hiro, 1933) from Japan.

B. rossi n. sp. is very distinct from B. cochlearium and can be distinguished by the latter having the upper-latus with a distinct shape and a fringed basal margin, the tergum with thinner branches, the carina with the roof bordered by prominent ridges, and the carino-latus with a concavity.

On the other hand, B. sanctabarbarae is very similar to B. rossi n. sp. but the former has the capitulum with a strongly convex occludent margin, the rostro-latus is very low, and it has a rostrum.

Barbascalpellum rossi n. sp. is known only from the type locality, N. Ireland, from 1600 m.

Figures

FIG. 16. — Barbascalpellum rossi n. sp., holotype, PROSPEC, stn CPH 10; A, left lateral view; B, carinal view; C, rostral view. Scale bars: 5 mm.

FIG. 17. — Barbascalpellum rossi n. sp., holotype, PROSPEC, stn CPH 10; A, labrum and palp; B, palp; C, mandible; D, maxilla I; E, maxilla II; F, cirrus I; G, median article of cirrus VI; H, cirrus VI protopodite and caudal appendage. Abbreviations: a, anterior ramus; C I, cirrus I; C VI, cirrus VI; ca, caudal appendage; mg, maxillary gland; p, posterior ramus. Scale bars: A, H, 1 mm; B-E, G, 0.3 mm; F, 2 mm.