Oncopagurus curvispina ( de Saint Laurent, 1974 )

Lemaitre, Rafael, 2014, A worldwide taxonomic and distributional synthesis of the genus Oncopagurus Lemaitre, 1996 (Crustacea: Decapoda: Anomura: Parapaguridae), with descriptions of nine new species, Raffles Bulletin of Zoology 62, pp. 210-301 : 237

Oncopagurus curvispina ( de Saint Laurent, 1974)

Figs. 15 , 51

Parapagurus curvispina de Saint Laurent, 1974: 791 , figs 1–5 (type

locality: Île Amsterdam, southern Indian Ocean). Sympagurus curvispina – Lemaitre, 1989: 37, table 1. Paragiopagurus curvispina – Lemaitre, 1996: 207. Oncopagurus curvispina – McLaughlin et al., 2010: 39; Lemaitre,

2013: 303.

Type material. Holotype, southern Indian Ocean , Île Amsterdam, sta AMS–D9, 50– 60 m, 23 January 1972, coll. J. Beurois: M 3.1 mm ( MNHN Pg. 3183).

Additional material. None.

Diagnosis. Shield ( Fig. 15A ) about as broad as long; rostrum broadly rounded, weakly produced, with short mid–dorsal ridge; lateral projections subtriangular, reaching to about same level of distal portion of rostrum, terminating in small spine. Ocular peduncles more than half length of shield, with dorsal row of setae; corneas moderately dilated. Ocular acicles subtriangular, terminating in strong spine. Antennular peduncle ( Fig. 15A ) exceeding distal margin of corneas by nearly entire length of ultimate segment. Antennal peduncle ( Fig. 15A ) not exceeding distal margin of cornea; fourth segment with small spine on dorsolateral distal angle; second segment with terminating in strong, simple or multifid spine, mesial margin with spine on dorsodistal angle; first segment with small spine on lateral face; acicle weakly curved (in dorsal view), short, only reaching to about proximal margin of cornea, terminating in strong spine, mesial margin armed with row of 8–10 spines; flagellum missing from holotype. Mouthparts not dissected; third maxilliped with crista dentata, teeth diminishing in strength distally. Right cheliped ( Fig. 15B ) with scattered setae, chela operculate; dactyl set at strongly oblique angle to longitudinal axis of palm; palm broader than long, dorsal face with double row of tubercles or spines medially, dorsolateral and dorsomesial margins well delimited by row of blunt to sharp spines, mesial face strongly sloping, ventromesial face with small tubercles or spines, ventral surface smooth; carpus dorsal face with numerous small spines or tubercles, dorsolateral margin well defined by row of spines at leats distally. Left cheliped ( Fig. 15C ) weakly calcified on dorsolateral face of carpus; palm with dorsomesial row of small spines; carpus with dorsodistal spine; carpus with small spines or tubercles on dorsal margin. Ambulatory legs with dactyls ( Fig. 15E ) each having ventromesial row of 11–13 corneous spinules; propodus with row of small spines on dorsal margin; carpus with small dorsodistal spine and row of small spines on dorsal margin. Anterior lobe of sternite XII (between second ambulatory legs) rounded, setose, with subterminal spine. Fourth pereopod propodal rasp ( Fig. 15F ) with 1 row of rounded scales at least distally. Fifth pereopod propodal rasp extending to or beyond mid-length of segment. Uropods and telson markedly asymmetrical; telson ( Fig. 15G ) lacking or with obsolete transverse suture, posterior lobes separated by shallow U-shaped cleft, terminal margin of lobes armed with often curved corneous spines. Male with paired first and second gonopods; first gonopods with ovate distal lobe, marginally setose; second gonopods with distal segment spatulate and with setae distally. Female unkown.

Colouration. Unknown.

Habitat. Presumably a gastropod shell.

Distribution. So far known only from the holotype collected at Île Amsterdam, southern Indian Ocean. Depth: 50– 60 m.

Remarks. Based exclusively on de Saint Laurent’s (1974) original description, this species was placed in Sympagurus Smith, 1883 by Lemaitre (1989), and then in Paragiopagurus Lemaitre, 1996 by Lemaitre (1996). However, an examination of the male holotype and only known specimen of this taxon, revealed the presence of a curved epistomial spine, a unique and defining character of Oncopagurus . Thus, this taxon was rightfully transferred to Oncopagurus by McLaughlin et al. (2010). Although the holotype is in poor shape, with the right cheliped and two ambulatory legs detached, the pleon partially torn, and missing the left first and second gonopods as well as the right antennal flagellum, it is enough to consider this taxon as a valid species, at least until the parapagurid fauna from the southern Indian Ocean is adequately sampled and can be properly evaluated.

Figures

Fig. 15. Oncopagurus curvispina (de Saint Laurent, 1974), holotype, male 3.1 mm, Île Amsterdam, southern Indian Ocean (MNHN Pg 3183). A, shield and cephalic appendages, dorsal; B, carpus and chela of right cheliped, dorsal; C, left cheliped, mesial; D, right second ambulatory leg, lateral; E, dactyl of same, mesial; F, propodus and dactyl of left fourth pereopod, lateral; G, telson, dorsal. Scale bars = 2 mm (A); 1 mm (B, E); 2 mm (C, D); 1 mm (G). [Adapted, in part, from de Saint Laurent (1974)].

Fig. 51. Bathymetric distribution of Oncopagurus species from the world, with maximum and minimum depths (meters) indicated for each.