Zilchia germani Pretzmann, 1978

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 : 604

Zilchia germani Pretzmann, 1978

( Figs 10A, B; 14)

Potamocarcinus ( Zilchia) zilchi germani Pretzmann, 1978: 3 ; 1980: 658, pl. 8 figs 32-36, pl. 16 fig. 72 [see Remarks].

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

Zilchia zilchi germani – Villalobos Hiriart & Álvarez 2008: 298 (in list). — Wehrtmann et al. 2016: 782 (in list).

TYPE MATERIAL EXAMINED. — Holotype. Guatemala • 1 ♂ (26.4:16.5); Guatemala, 14 km south of Guatemala City, near San José Pinula ; [ 14°33’01.34”N, 90°26’54.00”W; 1880 m elev.]; date unknown; I. Poglayen-Neuwall leg.; NHMW 4063 .

OTHER MATERIAL EXAMINED. — Guatemala • 1 ♂ (23.5:14.5); Guatemala, Santa Catarina Pinula [ 14°34’N, 90°30’W], km 14 en la carretera a El Salvador ; 1850 m elev.; VIII.1993; R. Dix; UVGCR 309 • 1 ♂ (27.3:17.5); Guatemala, Santa Catarina Pinula, Puerta Parada [ 14°34’N, 90°27’W], Río Acatán ; 1880 m elev.; X.1990; R. Dix leg. UVGCR 224 .

COMPARATIVE MATERIAL EXAMINED. — El Salvador • 1♂ (23.6:13.9), holotype of Zilchi zilchi ( Bott, 1956) ; Department Santa Ana, hacienda Los Planes ; date and leg. unknown; SMF 2445 .

DISTRIBUTION. — Guatemala ( Guatemala) ( Pretzmann 1978; this study) ( Fig. 14).

DESCRIPTION OF G1 ( Fig. 10A, B)

Stem moderately compressed mesolaterally, nearly straight in mesocaudal view, distal portion slightly bend cephalad in laterocephalic view; cephalic margin slightly convex, caudal margin slightly concave in mesocaudal view. Mesial surface with irregular row of few long setae longitudinally on median portion. Marginal suture nearly straight on mesial surface, with row of long setae along its proximal portion. Marginal process large, lamelliform, not overreaching mesocaudal margin of apex. Lateral suture incomplete, marked by sulcus along first 4/5 of the caudal surface, shallower distally. Mesial process moderately developed, strong, subtriangular, its length subequal to width of apex, slightly recurved, both margins unarmed. Cephalic surface nearly straight distally, with cephalic process as short conical spine, and well-developed spiny cephalic lobe. Terminal portion of mesial surface with distinct rounded, spined subapical lobe nearly coalescent with also spined, enlarged portion of mesocephalic margin of apex. Apex narrow, slit-like, elongated in caudocephalical direction; its margins asymmetric, mesocaudal margin low and unarmed towards caudal side, with enlarged and spined lobe towards cephalic side and slightly projected in cephalic direction; laterocephalic margin unarmed. Field of apical spines poorly developed, directed towards cephalic side, narrow, with short spines distributed along the caudocephalic length, nearly concealed by margins.

REMARKS

So far, this taxon has been treated as a subspecies of Zilchia zilchi (see Pretzmann 1978; Ng et al. 2008; Villalobos Hiriart & Álvarez 2008; Wehrtmann et al. 2016). A comparison with the G1 of the holotype of the nominal subspecies showed that Z. germani has a subapical, rounded, spined lobe on the distal portion of mesial surface (“sal” in Fig. 10A, B), whereas in Z. zilchi this lobe is reduced to a vestigial spine (“sal” in Fig. 10C). Furthermore, the cephalic lobe on the distal portion of the cephalic side is more developed and slightly larger and narrower than the cephalic spine in Z. germani (“cp” and “cl” in Fig. 10B), whereas it is less developed and slightly lower and wider than the cephalic spine in Z. zilchi ( Fig. 10D). The mesocaudal margin of apex is somewhat more enlarged and slightly higher in Z. germani (“am” in Fig. 10A, B) than in Z. zilchi (“am” in Fig. 10C, D). These differences justify treating them as separated species.

Pretzmann (1980: 658) mixed up the captions of the illustration for this species with those for Isabellagordonia ( Phrygiopilus) acanthophalla ibarrai (see Pretzmann 1980: 659); the actual information for Potamocarcinus ( Zilchia) zilchi germani in Pretzmann (1980: 658) should be: “plate 8 figs 32-36, plate 16 fig. 72” (C. Magalhães, pers. observation). The information of the type locality was also mixed up in that publication: the correct type locality is “ Guatemala, Department of Guatemala, 14 km south of Guatemala City, near San José Pinula”, and not “Río Guyamas, NE El Progreso, Honduras ” ( Wehrtmann et al. 2016).