Sylvathelphusa kalebi, Villalobos, José Luis & Álvarez, Fernando, 2013

Villalobos, José Luis & Álvarez, Fernando, 2013, Two new genera and three new species of freshwater crabs (Crustacea: Pseudothelphusidae: Potamocarcinini) from Chiapas, Mexico, Zootaxa 3599 (5), pp. 457-470 : 459-463

publication ID

https://doi.org/ 10.11646/zootaxa.3599.5.3

publication LSID

lsid:zoobank.org:pub:C668DAB3-5A86-4FAB-B14C-7A05BADF149D

DOI

https://doi.org/10.5281/zenodo.6146612

persistent identifier

https://treatment.plazi.org/id/410487DC-B719-1D7E-FF23-5423FB8453C0

treatment provided by

Plazi

scientific name

Sylvathelphusa kalebi
status

sp. nov.

Sylvathelphusa kalebi View in CoL n. sp.

( Figs. 2 View FIGURE 2 , 3 View FIGURE 3 )

Type material. Holotype: male, cb 17.3 mm, cl 10.5 mm; allotype: female, cb 14.8 mm, cl 9.6 mm; paratype: male, cb 15.1 mm, cl 9.4 mm; La Pera nature reserve, 12 km NE of Berriozábal (16°49'53" N, 93°17'42" W; 1178 m), Municipio de Tuxtla Gutiérrez, Chiapas, Mexico; 12 Sep 2008; colls: K. Zárate, I.A. Córdoba, A.J. Flores, C.A. Pérez, G. Salinas; CNCR 26179.

Other material examined (non-types). 5 males, cb 12.0- 15.5 mm, cl 7.8-10.5 mm; 2 females 15.0 mm both, cl 9.2-9.5 mm; same locality as holotype; 27 Nov 2008; colls: J.L. Villalobos, C. Hernández, K. Zárate, A. García, C. Enríquez, E. Torres; CNCR 26181.

Description. Small sized crabs (cb <17.3 mm). In dorsal view, carapace oval shaped, widest in the middle; dorsal surface flat, punctated, regions faintly indicated; pair of gastric pits barely distinct, oblique, elongated, close to each other on metagastric region; cervical grooves narrow, shallow, straight, not reaching anterolateral margin of carapace ( Fig. 2 View FIGURE 2 a). Postfrontal lobes distinct, low, separated by median groove. Frontal region granulated, depressed with respect to carapace surface; inferior frontal border granulated, projected, bilobed, with deep medial notch; superior frontal border straight, bilobed in dorsal view, lobes defined by row of sharp granules separated by shallow mesial notch ( Fig. 2 View FIGURE 2 a). Superior margin of orbit formed by granules, continuous with inferior frontal border; lower orbital margin marked by row of granules; exorbital angle projected, narrow, acute. Lateral margins of carapace serrated, anterior half with sharp granules, posterior half smooth. Posterior margin of carapace slightly concave.

Eyes with cornea pigmented, faintly faceted, not filling orbits ( Fig. 2 View FIGURE 2 d). Epistome narrow, epistomial tooth low, triangular, slightly deflexed, borders smooth ( Fig. 2 View FIGURE 2 c). Suborbital, subhepatic and pterygostomian regions pubescent. Third maxilliped with ratio exopod/ischium 0.47, ischium with outer margin slightly sinuous, inner margin straight, external margin of merus widely curved ( Fig. 2 View FIGURE 2 c). Aperture of efferent branchial channel subrectangular.

Chelipeds subequal in size and shape; merus subtriangular in cross section, 4.3 times as long as wide, superior internal border with row of conical and acute spines, increasing in size distally, alternating with small spinules. Carpus smooth, prominent and acute subdistal spine on inner side. Chela slender (length/height 3.6), surface smooth, with faint minute teeth on upper and lower rounded borders. Fingers slender, as long as palm, not gaping, tips crossing; both fingers with sharp triangular teeth on cutting edges, becoming smaller distally; dactylus with alternating large and small teeth ( Fig. 2 View FIGURE 2 b). Thoracic sternites of third maxillipeds and first pereiopods completely fused, except for small notches at lateral edges of sternum; sternal sulci s4/s5, s5/s6 and s6/s7 distinct, just failing to reach midline of thoracic sternum. All abdominal segments free. Telson subtriangular, narrow; lateral margins distinctly straight, tip rounded.

Male gonopod not completely chitinized, latero-mesially compressed, slightly arched in caudal and cephalic views, distal half wider. In mesial view, marginal suture almost straight along most of gonopod, slightly concave in middle ( Fig. 3 View FIGURE 3 a). Marginal plate between caudal and mesial surfaces, without marginal setae basally; distal half widening distally, ending in triangular apical projection overreaching mesial process, lying on caudal margin of apical projection, ending in acute distal margin with triangular tubercle ( Fig. 3 View FIGURE 3 a). Caudal portion of marginal plate limited by lateral suture, distal third rounded. Mesial surface ending in tongue-like apical projection, distocephalically directed, longer than apical projection of marginal plate, distal margin broad, rounded, sculptured with shallow longitudinal grooves and scattered subacute granules ( Fig. 3 View FIGURE 3 a). Mesial process as triangular, stout, acute spine, directed cephalad, forming 90º angle with respect to principal axis of gonopod ( Fig. 3 View FIGURE 3 a). Caudal surface with medial shallow, rounded notch. Lateral suture visible through proximal two thirds, apically separating marginal plate from caudal surface. In cephalic view, mesial process conical, stout, acute ( Fig. 3 View FIGURE 3 b). Lateral surface with small triangular distomedial tubercle ( Fig. 3 View FIGURE 3 b); distal third of laterocaudal portion forming high, rounded border, with central depression ( Fig. 3 View FIGURE 3 b). Distal end of marginal plate subacute. In lateral view, caudal surface with medial constriction ( Fig. 3 View FIGURE 3 c). Lateral surface becoming broader caudally, forming on distal third ample plate with high caudal margin, laterally directed ( Fig. 3 View FIGURE 3 c). Deep suture at base of apical projection of mesial surface, separating lateral and mesial plates ( Fig. 3 View FIGURE 3 c). In caudal view, gonopod slightly arched laterally ( Fig. 3 View FIGURE 3 d). Distal half with lateral margin expanded, with low, distal, triangular prominence ( Fig. 3 View FIGURE 3 d). In apical view, apical portion of marginal plate ending in acute tip ( Fig. 2 View FIGURE 2 e). Mesial surface with broad, rounded distal margin, with few granules ( Fig. 2 View FIGURE 2 e). Mesial process conical, stout, acute, directed cephalically ( Fig. 2 View FIGURE 2 e). Apical cavity covered by hood formed by distal crest of lateral surface. Opening of spermatic channel located caudally ( Fig. 2 View FIGURE 2 e).

Color in life. Carapace dark olive or gray, chelipeds white and ambulatory legs light brown, thoracic sternites and abdomen light yellow.

Etymology. The species is named after Kaleb Zárate, biologist and speleologist, who first discovered this population.

Remarks. This is the first record of a completely terrestrial pseudothelphusid crab in Mexico, although Pseudothelphusa parabelliana Álvarez, 1989 , Odontothelphusa maxillipes ( Rathbun, 1898) , Potamocarcinus magnus ( Rathbun, 1895) and Raddaus bocourti ( A. Milne-Edwards, 1866) , have been observed at considerable distances from the nearest stream. The crabs representing the new species were found in a tropical rainforest NE of the town of Berriozábal, at altitudes ranging from 950 to 1200 m. They were found under limestone in crevices, where the soil is humid and contains abundant organic matter composed of leaf litter in different stages of decomposition. No streams, rivers or other aquatic bodies were observed nearby.

GBIF Dataset (for parent article) Darwin Core Archive (for parent article) View in SIBiLS Plain XML RDF