Alvarezius Moreno & Villalobos, 2022

Moreno-Juárez, Eric G., Villalobos, José Luis & Álvarez, Fernando, 2022, Two new genera and one new species of freshwater crabs of the subfamily Pseudothelphusinae (Decapoda: Brachyura: Pseudothelphusidae) from southwestern Mexico, Zootaxa 5200 (1), pp. 24-36 : 31-32

Alvarezius Moreno & Villalobos n. gen.

( Fig. 5 )

urn:lsid:zoobank.org:act:DDF1CE7E-C440-4DD6-A41C-CEC2960509EF

Diagnosis. G1 with conical setiferous prominence on latero-caudal portion of distal border of apical cavity. Caudomarginal projection unilobed, which extends proximally reaching proximal half of gonopod principal axis, distocephalic border serrate. Mesial process subrectangular, proximal inferior angle ending in acute triangle proximally oriented.

Type species. Pseudothelpusa zongolicae Alvarez, Villalobos & Moreno, 2012 .

Species included. Alvarezius zongolicae ( Alvarez, Villalobos & Moreno, 2012) n. comb.

Etymology. The genus name is dedicated to Dr. Fernando Álvarez, eminent Mexican carcinologist and curator of the CNCR. The gender of this name is masculine.

Distribution. Only known from Zongolica region, Veracruz, Mexico.

Remarks. When Pseudothelpusa zongolicae was first described, it was included in this genus because of the similarities in the G1 regarding the caudo-marginal projection and the mesial process as in other species of this genus, as explained by Alvarez et al. (2012). In the phylogenetic analysis presented in this paper P. zongolicae was recovered as the sister lineage to Tehuana , with mean genetic distance of 4.0% with respect to all the species of the genus, and 8.0–9.0%with respect to to species of Pseudothelphusa . Combining the genetic evidence with a new morphological description, we place P. zongolicae in the new genus Alvarezius n. gen.

Figures

FIGURE 5. Alvarezius zongolicae n. comb. a) carapace dorsal view, b) carapace frontal view, c) chela, d) third maxilliped. G1 views: e) mesial, f) cephalic, g) lateral; h) caudal, i) distal. Abbreviations: Cmp) caudo-marginal projection; Csp) Conical setiferous prominence; Mp) Mesial process; Sf) spine field. Scales as broad lines e-h: 2 mm; i: 1 mm (taken and modified from Alvarez et al. 2012).