Zilchia falcata Rodríguez & Hobbs, 1989

Magalhães, Célio & Wehrtmann, Ingo S., 2025, Taxonomic revision and distribution of the freshwater crabs of the family Pseudothelphusidae (Decapoda, Brachyura) from Guatemala, with the descriptions of two new species and keys to the species of all genera, Zoosystema 47 (26), pp. 581-615 : 602-604

Zilchia falcata Rodríguez & Hobbs, 1989

( Figs 9; 14)

Zilchia falcata Rodríguez & Hobbs, 1989: 184 , figs 1, 2, 3G. — Rodríguez 1992: 184 (in list). — Guinot 1994: 171, pl. 1 fig.7. — Hobbs 1994: 101 (in list). — Villalobos Hiriart & Álvarez 2008: 298 (in list). — Cumberlidge et al. 2014: 144 (in table). — Wehrtmann et al. 2016: 782 (in list). — Acevedo-Alonso & Cumberlidge 2022: 584 (Appendix 2, in list).

Potamocarcinus falcatus – Ng et al. 2008: 176 (in list).

TYPE MATERIAL EXAMINED. — Holotype. Guatemala • 1 ♂; Alta Verapaz, exact locality unknown; 1975; collected by the Dreux Expedition; MNHN-IU-2008-11065 (= MNHN-B20118 ) as in Rodríguez & Hobbs (1989).

Paratype. Guatemala • 1 ♂; MNHN-IU-2014-11972 (= MNHNB20352 ), as in Rodríguez & Hobbs (1989) .

OTHER MATERIAL EXAMINED. — Guatemala • 1 ♂; Alta Verapaz, exact locality unknown; 1975; collected by the Dreux Expedition; MNHN-IU-2014-10311 (= B27918 ) .

DISTRIBUTION. — Guatemala ( Alta Verapaz) ( Rodríguez & Hobbs 1989) ( Fig. 14).

DESCRIPTION OF G1 ( Fig. 9C, D)

Stem moderately compressed mesolaterally, falciform in overall appearance, distal portion distinctly arched cephalad in laterocephalic view; lateral margin convex, caudal margin concave in mesocaudal view; some short seta present along both margins. Caudal surface with small protuberance on median portion of caudal margin; mesial surface with irregular row of few long and short setae longitudinally along proximal half. Marginal suture on mesial surface distinctly curved caudally on distal end, with row of long setae along its proximal portion. Marginal process large, lamelliform in mesocaudal view, not overreaching mesocaudal margin of apex. Lateral suture incomplete, marked by sulcus along first 4/5 of mesocaudal surface, shallower distally. Mesial process (“cephalic process” sensu Rodríguez & Hobbs 1989) greatly developed, strong, subtriangular, long (approximately 1.2 longer than width of apex, measured in mesocaudal view), recurved. Cephalic surface strongly concave distally, with cephalic process as short conical spine (“basal spine” or “lateral process” sensu Rodríguez & Hobbs 1989) situated near base of mesial process; smooth otherwise. Apex oblong, elongated caudocephalicaly; its margins asymmetric, mesocaudal margin higher than laterocephalic one, both unarmed, outline of mesocaudal margin rounded. Field of apical spines well developed, open (not concealed by apical margins), obliquely directed towards cephalic side, narrow, with short spines distributed in caudocephalic direction.

REMARKS

The exact locality in the department of Alta Verapaz where the types of Z. falcata were collected is unknown (the distribution record in the Figure 14 is arbitrarily represented in the center of the department: approximately 15°39’36”N, 90°05’10”W). Rodríguez & Hobbs (1989), based on Delamare Deboutteville (1976b) and Delamare Deboutteville & Juberthie (1976), only indicated that they were collected by the Dreux Expedition in 1975. This expedition explored more than 400 caves in that department in the years 1974-1975 (Courbon & Dreux 1976; Courbon et al. 1976).