Gruvelialepas Newman, 1980

Young, Paulo S., 2002, Revision of the Scalpellidae (Crustacea, Cirripedia) in the collection of the Muséum national d’Histoire naturelle, France, studied by Abel Gruvel, Zoosystema 24 (2), pp. 309-345 : 315-318

Genus Gruvelialepas Newman, 1980

Gruvelialepas pilsbryi ( Gruvel, 1911) ( Figs 4-6 )

Scalpellum pilsbryi Gruvel, 1911: 290 ; 1912: 346, pl. 7, fig. 2. — Klepal 1987: 304.

Calantica (Scillaelepas) pilsbryi – Krüger 1940: 462.

Scillaelepas pilsbryi – Zevina 1976: 1150; 1978a: 1001; 1981a: 68.

Scillaelepas (Gruvelialepas) pilsbryi – Newman 1980: 391, figs 11, 12.

Gruvelialepas pilsbryi – Young 1998a: 12, fig. 8b.

TYPE MATERIAL. — South of Cape Bojador, on bryozoans, 882 m, Talisman, 1883 , paralectotype, cl (tl) 13.6 (22.8) mm ( MNHN Ci 1).

DIAGNOSIS. — Capitulum with 15 plates, including two subrostra; rostro-latus separated from carino-latus; peduncular scales small, rounded.

DESCRIPTION

Hermaphrodite. Capitulum ( Fig. 4A ) with 15 plates, covered by thick cuticle; length a little larger than width; carinal margin slightly convex, occludent margin convex. Plates thick, with longitudinal ridges and thin growth lines. Plates mostly approximate from each other.

Scutum ( Fig. 4A ) triangular, with an apicobasal ridge, with both sides flat, but angulose along ridge; length 1.5 time its width; occludent and basal margins slightly convex, tergal margin concave; apex slightly curving outward.

Tergum ( Fig. 4A ) balloon-shaped, with a large, flat apicobasal ridge dividing plate in two similar, flat sides; apex slightly curving outward; occludent margin straight, carinal margin slightly convex; surface area larger than that of scutum.

Carina ( Fig. 4A, C ) slightly arched, with a narrow tectum and two large, flat laterals, basal margin cutted V-shaped, umbo apical, projecting upwards, extending up to mid-point of carinal margin of tergum.

Upper-latus (L1) ( Fig. 4A ) triangular, symmetrical, wider than high, concave medially, situated in the lower whorl; apex nearly straight, situated between scutum and tergum junction.

Rostrum ( Fig. 4A, B ) large; about one third the length of scutum; projected backward, and slightly curved toward scuta; tectum concave medially.

Rostro-latus and carino-latus ( Fig. 4A, B ) separated from each other, triangular, wider than high, slightly concave medially; umbos incurved. Sub-carina( Fig.4A,C ) triangular, equilateral,as wide as high, umbo apical; apex strongly curved to carina. Sub-rostrum 1 ( Fig. 4A, B ) triangular, surface slightly concave and sub-rostrum 2 triangular with surface convex.

Peduncle ( Fig. 4A ) short, about two thirds length of capitulum. Cuticle thick, covered by several small nearly triangular scales.

Prosoma without filamentary appendages.

Labrum ( Fig. 5A ) bullate, crest without teeth. Palp ( Fig. 5A ) small, paddle-like, finely pinnate setae along the inner margin and surface. Mandible ( Fig. 5B ) with four teeth, fourth with upper margin denticulate, lower angle denticulate; distance between first and second tooth almost same of between second and third. Maxilla I ( Fig. 5C ) with cutting edge irregular in outline; upper portion with two large, strong and one median, strong setae, followed by six small spines in a large concavity, seven median spines on a projection and several small, thin spines below. Maxilla II ( Fig. 5D ) slightly bilobed, with finely pinnate long setae along margins, except in the notch; papilla of maxillary gland not projecting.

Cirrus I ( Fig. 6A ) not situated far apart from the cirrus II with anterior ramus shorter than posteri- or, about 0.7 time length of posterior; basal articles protuberant, clothed with numerous, simple and finely pinnate setae. Cirri II-VI with equal rami; intermediate articles of cirrus VI ( Fig. 6B ) about twice longer than wide, armed with four pairs of long, finely pinnate setae, setulae at the base of long setae, and one small seta between each longer setae pair on anterior margin; two to six long setae simple or finely pinnate on posterior angle. Setal-article ratio about 5:1. Caudal appendage ( Fig. 6C ) unarticulated, short, about one quarter the height of coxopodite of cirrus VI, with few simple setae at apex. Penis absent. Males absent. Number of articles of cirri I-VI is presented in Table 2.

REMARKS

This species was studied by Newman (1980) who described one specimen of the type series. In order to give more details of the appendages and to compare them with that studied by Newman, I dissected another specimen, which presented some distinctive characters from that previously dissected: 1) the prosoma did not present any filamentary appendages and Newman (1980: 391) observed two sets of filamentary appendages; 2) the intermediate article of cirrus VI was armed with four pairs of long setae and Newman observed five pairs.

The numbers of setae on the articles of cirrus VI probably are variations related to distinct sizes of the specimens. But the variations in the number of filamentary appendages are very curious. By all the other characteristics I discard the possibility that the type series of S. pilsbryi contains more than one species. Therefore, the variation in the number of filamentary appendages can be accepted as a variation of the species. The number of filamentary appendages is commonly used for distinguishing species in several genera (e.g., Lepas and Glyptelasma ) and to my knowledge the variation in their number was not reported before.

Gruvelialepas pilsbryi was described from south of Bojador Cape, 882 m ( Gruvel 1911, 1912) and subsequently reported only once from Meteor seamounts ( Young 1998a). Gruvel (1920: 79) cites in the list of species G. pilsbryi as having been collected by SAS Le Prince de Monaco Expedition in the station 1349 (38°35’30”N, 28°05’45”W, 1250 m), but this species is not presented in any part of the text. In this station, he also found Scillaelepas grimaldi , which is discussed in the main text. Therefore, I consider this record of G. pilsbryi an error of citation, which was probably a first identification of the other Scillaelepas s.l. collected.

Family SCALPELLIDAE Pilsbry, 1907

Figures

FIG. 4. — Gruvelialepas pilsbryi (Gruvel, 1911), paralectotype (MNHN Ci 1); A, left lateral view; B, rostral view; C, carinal view. Scale bars: A, 5 mm; B, C, 3 mm.

FIG. 5. — Gruvelialepas pilsbryi (Gruvel, 1911), paralectotype (MNHN Ci 1); A, labrum and palp; B, mandible; C, maxilla I; D, maxilla II. Scale bar: 0.5 mm.

FIG. 6. — Gruvelialepas pilsbryi (Gruvel, 1911), paralectotype (MNHN Ci 1); A, cirrus I; B, median article of cirrus VI; C, coxopodite of cirrus VI and caudal appendage. Scale bars: A, 1 mm; B, C, 0.5 mm.