Calyptraeotheres pepeluisi, Campos, Ernesto & Hernández-Ávila, Iván, 2010

Campos, Ernesto & Hernández-Ávila, Iván, 2010, Phylogeny of Calyptraeotheres Campos, 1990 (Crustacea, Decapoda, Brachyura, Pinnotheridae) with the description of C. pepeluisi new species from the tropical Mexican Pacific, Zootaxa 2691, pp. 41-52 : 45-50

Calyptraeotheres pepeluisi new species

( Figs. 3 , 4 )

Material. Holotype ( CNCR 26183), ovigerous female, 10 July 1983, collected by trawl, off Lázaro Cardenas port, Michoacán, Pacific coast of Mexico, oceanographic expedition Atlas IV on board of the R/V El Puma of the UNAM, June 1983, locality A-IV, C4-13, 18 º 04’44” N 18º 05’ 02” N, 102º 33’ 18” W 102 º 33’ 04”.

Host. Unknown.

Description of holotype female. Carapace suborbicular, with pilose sub-rectangular front, slightly projected, with medial shallow sulcus; anterolateral margin pilose, arcuate, cristate; regions poorly defined; posterior margin slightly curved; 2 cervical depressions from orbits to gastric region, converging posteriorly. Eyes visible in dorsal view. MXP3 placed obliquely, exopod with unsegmented flagellum; endopod with ischium and merus fused, widening distally, palp 2-segmented, articulating distally on inner margin; carpus sub-trapezoidal, larger than sub-conical propodus; dactylus absent. Chelipeds stout, dorsodistal margin of carpus with small rounded projection; chela longer than combined merus-carpus length, palm widening distally, dorsal margin unarmed, ventral margin of propodus slightly curved with fringe of minute setae, dactylus curved, cutting margin with proximal tooth inserted in notch of propodus, fingers without gape when closed, tips crossed, both fingers with additional minute teeth; outer surface of chela slightly convex, inner surface convex dorso-proximally, slightly concave distally, with ventro-proximal depression. Relative length of WL in decreasing order 3 =2>1>4, margins unarmed, WL 1–3 of similar shape, WL 4 relatively slender. Dactyl falcate, relative length 4> 3> 2> 1; dactyli shorter than propodi in WL 1–3, dactylus of WL 4 slightly larger than propodus. Abdomen with 6-somites, telson distinctly separated, covering sternum, reaching buccal cavity.

Etymology. This species is named in honor of our colleague and friend Pepe-Luis, the nickname of José Luis Villalobos-Hiriart (CNCR, Instituto de Biología, UNAM) for his numerous contributions to systematics and phylogeny of Decapoda and his invaluable support to our studies on pinnotherid crabs.

Type locality and distribution. Known only from the type locality, off the Lázaro Cárdenas port, Michoacán, Pacific coast of Mexico.

Taxonomic remarks. Calyptraeotheres pepeluisi new species is the third species of the genus recorded in the Pacific Ocean. It differs from the two austral (southern hemisphere) species, C. garthi (Atlantic: Argentina and Brazil) and C. politus (Pacific: Peru and Chile) by its 2-segmented MXP3 palp ( Fig. 4 B–C) instead of a 3- segmented palp (see Campos 1999, Fig. 4 A–B). Both C. hernandezi (Caribbean Sea: Venezuela) and C. granti (Mexican Pacific) share a 2-segmented MXP3 palp with C. pepeluisi , but this latter species is morphologically closer to the former species. Calyptraeotheres hernandezi and C. pepeluisi share a subarcuate carapace, with a fringe of setae on its anterolateral and frontal margins ( Fig. 3 A), a conical MXP3 propodus, and dorsally visible eyes. This resemblance provides evidence that C. pepeluisi is the Pacific counterpart of C. hernandezi and that both species probably evolved after the complete closure of the Isthmus of Panama 3.1–3.5 MYA ( Keigwin, 1982; Coates & Obando, 1996). In spite of the fact that C. pepeluisi , C. hernandezi and C. granti have a 2-segmented MXP3 palp, it is remarkable that the shape of the propodus of this appendage in the former two species (conical) is quite different from that observed in the latter species (subtrapezoidal). Furthermore, in C. granti the eyes are not visible in dorsal view and it has a subpentagonal carapace with a glabrous margin instead of a subarcuate carapace, with the margin setose and eyes visible in dorsal view. Calyptraeotheres pepeluisi can be separated from C. hernandezi as follows: eyes proportionally smaller; posterior margin of carapace less concave; carapace without a shallow transverse T-shaped depression connecting both longitudinal sulci; and margins of ischium-merus and external margin of carpus with pinnate setae (simple setae in C. hernandezi ). Calyptraeotheres pepeluisi can be separated from its Pacific congener, C. granti , as follows: carapace with the lateral margin arcuate instead of subparallel; eyes visible in dorsal view (not visible in dorsal view in C. granti ), and MXP3 propodus conical, not obliquely truncated as in C. granti . The host for the new species is not known.

Figures

FIGURE 3. Calyptraeotheres pepeluisi new species, off Lázaro Cárdenas port, Michoacán, Mexico (CNCR 26183). Adult female: A, dorsal view; B, partial frontal view.

FIGURE 4. Calyptraeotheres pepeluisi new species, off Lázaro Cárdenas port, Michoacán, Mexico (CNCR 26183). Adult female: A, abdomen, somites 3 – 6 and telson; B – C, MXP 3, inner and outer views respectively; D, cheliped; E, tip of cheliped.