Parapinnixa bolagnosi, Hernández-Ávila, Iván & Campos, Ernesto, 2007

Hernández-Ávila, Iván & Campos, Ernesto, 2007, Parapinnixa bolagnosi, a new species of pinnotherid crab from Cubagua Island and Los Frailes Archipelago, Venezuela (Crustacea: Brachyura: Pinnotheridae), Zootaxa 1607, pp. 57-62 : 58-62

Parapinnixa bolagnosi new species

Figs. 1–2

Material examined. Cubagua Is., Venezuela.— Holotype: MMM.cr.03252, female, (CL= 1.88 CW= 3.68), Punta Yirú, 10º48'24.9''N 64º9'4.32''W, on rocks on Thalassia bed., 1.7 m depth, 75 m from the coast, coll. I. Hernández-Ávila & A. Gómez, November 11, 2003. Paratypes: Cubagua Is., Venezuela.— MMM.cr.03251, 1 female, (CL= 1.40 CW= 2.84), Playa El Medio, 10º50'14.7''N 64º9'14.88''W, associated with Halimeda opuntia , 3 m depth, 100 m from the coast, coll. I. Hernández-Ávila, August 27, 2003. MMM.cr.03253, 1 female, (CL= 1.78 CW= 3.40), Playa El Guichere, 10º48'15.06''N 64º9'37.32''W, on rocks, 2 m depth, 50 m from the coast, coll. I. Hernández-Ávila & A. Gómez, December 8, 2003. MMM.cr. 0 3254, 1 female, (CL= 1.0 CW= 2.14), Barranca Blanca, 10º48'4.98''N 64º10'25.68''W, on rocks, 2 m depth, 50 m from the coast, coll. I. Hernández-Ávila & A. Gómez, January 22, 2004. MMM.cr.03255, 1 female, (CL= 1.72 CW= 3.44), Punta El Olivito, 10º48'3.42''N 64º11'16.5''W, on rocks, 2.5 m depth, 75 m from the coast, coll. I. Hernández-Ávila & A. Gómez, February 19, 2004. Los Frailes Archipelago, Venezuela.— MMM.cr. 0 3662, 1 female (fragmented), (CL= 2.36 CW= 4.32), La Pecha, 11º06'N 63º48'W (approx.), 8 m depth between oysters, coll. A. Tagliafico, February, 2004.

Description. Carapace ( Fig. 1 a), very small, ovate, smooth, width 1.83–2.02 times length, dorsally convex; anterior margin somewhat straight, laterally arcuated, unarmed; front-orbital width 1/3 carapace width, front triangular, deflexed, tip hidden dorsally. Orbits rounded, eyes small, dorsally visible. Antennules folded in oblique fossettes ( Fig. 2 a). Epistome ( Fig. 2 a) with biconcave dorsal margin, medially pointed, wider than ventral concave margin, lateral margins obliquely curved. Buccal area subtriangular, basal breadth 1/4 carapace length.

MXP3 ( Fig. 2 d) subtrapezoidal, merus broadly subtrapezoidal, fused with ischium, distal margin slightly sinuous, dorsal margin slightly concave, with large plumose setae, ventral margin broadly convex, outer surface with short setae. Palp with two articles not extending beyond distal margin of merus, dactylus absent, carpus subtriangular, with large plumose setae; propodus minute, digitiform, exopod absent.

Chelipeds ( Fig. 1 b) symmetrical, stout, contour rounded, nearly as long as WL 1, merus short, lateroexternal surface subtrapezoidal, flattened; carpus rounded, merus and carpus with short setae on inner margin. Chelae ( Fig. 1 c) tomentose, length of palm subequal to height, longer than fingers, margins little concave, with minute granules on outer surface, mesiodorsal row of short setae on inner surface. Fingers subtriangular, curving at tip where they cross, base of the pollex wider than dactylus, cutting surface of pollex with small, medial serrate crest that ends in subtruncated tooth; cutting surface of dactylus smooth, gently curved, dorsal margin convex.

WL ( Figs. 1 d–g) decreasing in order from the largest WL1 to the smallest WL4; merus of WL1 ( Fig. 1 d) widening distally, inner surface proximally concave to accommodate the ischium-merus of cheliped, dorsal ridge setosed, distal width around 0.6 times length; carpus short, stout, dorsally subelliptical and convex, propodus tapering distally, subelliptical, ventral margin with short simple setae, dactylus small, subconical, somewhat falcate, tip corneous.

WL2 ( Fig. 1 e) compressed, merus little shorter but much slender than merus of WL1, greatest width 0.4 times its length; carpus longer than wide, subtriangular, propodus subrectangular, dorsal margin gently curved, ventral margin concave, ending in, a distal lobe, dactylus thin, somewhat falcate, tip corneous.

WL3 ( Fig. 1 f) smaller that WL2, merus width almost 0.5 times its length; carpus subtriangular, much shorter than subrectangular propodus, dactylus subconical, somewhat falcate, tip corneous.

WL4 ( Fig. 1 g) smallest, reaching distal margin of merus of WL3; merus width around 0.5 times its length; carpus, propodus and dactylus similar in shape that WL3 but proportionally smaller.

Abdomen ( Fig. 2 c) with six free segments and telson; third somite the widest; lateral margin convex; somites 4–6 tapering distally, lateral margins slightly convex; lateral margins of somites 2–6 with plumose setae; telson slightly more that twice as wide as long; subtriangular, with broad rounded corners, margin with long setae

Etymology. This species is named in honor to Juan Antonio Bolaños Curvelo, Professor of Carcinology of the Escuela de Ciencias Aplicadas del Mar, Universidad de Oriente, Venezuela, for his contributions to our knowledge of the larval development and taxonomy of decapods in northeastern Venezuela.

Remarks. Werding & Müller (1990) reported, with reservations, a male specimen as Parapinnixa cf. beaufortensis Rathbun, 1918 , which was collected in Bahía Chengue, near Santa Marta, Colombia. After a careful examination of Werding & Müller’s figure of the MXP3 ( Fig. 3 ), their specimen appears to have closer affinities with P. bolagnosi since both share a biarticulated palp and lack of exopod. The palp of the third maxilliped of Parapinixa beaufortensis Rathbun, 1918 has three articles. Since no males of P. bolagnosi are presently available for study it is not possible to determine whether or not Werding & Müller’s Colombian specimen is conspecific or if it represents a new species.

Ecological remarks. Parapinnixa bolagnosi has been collected associated with rocks in Thalassia beds, on aggregations of the calcareous algae Halimeda opuntia , between oysters, in Cubagua Island and Los Frailes Archipelago. One lost specimen was collected in the sponge Ircinia sp.

Figures

FIGURE 1. Parapinnixa bolagnosi new species. a, Holotype, dorsal view; b – g, Paratype; b, cheliped, outer surface; c, cheliped, inner surface; d – g, walking legs 1 – 4; b – c setae removed.

FIGURE 2. Parapinnixa bolagnosi new species. a, Holotype; frontal view; b-d, Paratype, b, antenae, c, abdomen; d, third maxilliped.

FIGURE 3. Third maxilliped of Parapinnixa cf. beaufortensis sensu Werding and Müller 1990 (not, P. beaufortensis Rathbun, 1918).