Pseudothelphusa queretana, Madrigal & Villalobos-Hiriart & Álvarez, 2025

Madrigal, Kevin J., Villalobos-Hiriart, José Luis & Álvarez, Fernando, 2025, Integrative taxonomic analysis of the Pseudothelphusa americana de Saussure, 1857 species complex with the description of three new species (Decapoda, Pseudothelphusidae, Pseudothelphusinae), Zootaxa 5659 (1), pp. 1-28 : 19-22

Pseudothelphusa queretana sp. nov.

http://zoobank.org/ CE78FBCC-00E3-41B7-BE7C-BE3A39A4699F

( Figures. 7 , 8 )

Pseudothelphusa americana – Villalobos-Hiriart 2005: 127 (in part).

Type material examined. Holotype (herein designated): male (CL 23.33 mm, CW 38.77 mm) ( CNCR 342 ), Querétaro-state of México, Mexico, coll. anonymous . Paratype: male (CL 21.16 mm, CW 34.02 mm) ( CNCR 344 ), same data as holotype .

Description. Carapace slightly convex; surface finely punctuated/reticulated, punctuation clustered on branchial and gastric regions, and between frontal border and postfrontal lobes ( Fig. 7B ). Superior frontal border present; front abruptly curved downwards, almost vertical; frontal border bilobed, continuous, thick, completely punctuated, with crenated appearance, central portion with shallow, wide depression ( Fig. 7A, B ). Postfrontal lobes marked, somewhat elevated; frontal median groove ill defined, moderately deep, narrow; cervical grooves well defined, slightly curved proximally, deep, not reaching anterolateral margin ( Fig. 7B ). Gastric region poorly delineated, convex; cardiac region marked by three shallow depressions; urogastric sutures Y-shaped, horizontally disposed, faintly inclined towards central portion, notably short ( Fig. 7B ). Notch on external orbital angle ( Fig. 7B ). Anterolateral margin with small, rounded granules, decreasing progressively in size anteriorly; posterior margin notably concave ( Fig. 7B ).

Superior frontal border forms an obsolete line in frontal view, slightly oblique, central portion interrupted by median groove; frontal border straight, convex at level of antennal fossae, wider at lateral angle ( Fig. 7A ). Orbits subquadrangular; inferior margin gently crenated, horizontally displayed; external angle subacute; internal tooth subtriangular, as grooved plate, separated from lateral angle of frontal border, leaving a narrow hiatus ( Fig. 7A ). Antennae not separated from front; antennal basal article partially covered by widening of lateral angle of frontal border ( Fig. 7A ). Interantennular septum visible, sharp, inserted under frontal border. Operculum of antennal gland ovoid, with tuft of bristles on external portion. Efferent channel aperture subquadrangular, width/length ratio 1.07. Epistomal tooth at septum level, triangular, downwards directed ( Fig. 7A ). Pterygostomial region and epistome pubescent. Third maxillipeds covering buccal cavity; ischium of third maxilliped subtrapezoidal, width/length ratio 0.91, gnathal margin with small subtriangular teeth decreasing in size distally, long bristle tufts in between teeth; merus of third maxilliped with anterolateral border rounded, extending beyond buccal cavity, width/length ratio 1.27; anterior notch well defined; gnathal border gently excavated for palp insertion, inferior margin with teeth and bristles; palp mesially pubescent, denser towards dactylus; surface punctuated, each punctuation with setae,, distributed longitudinally along gnathal margin; exognath wider at base, ending in acute apex, exognath/ischium ratio 0.65.

Chelipeds asymmetrical. Merus internal border with small tubercles, internal border of carpus with small, rounded granules, distally with triangular spine. Major chela with palm surface punctuated; fingers leaving narrow gap; dactylus slender, slightly curved; cutting borders with well-developed triangular teeth ( Fig. 7D ).

G1 strong, distal third twisted towards median axis of sternal surface of body. In caudal view, distal third slightly inclined mesially; distal crest of caudo-marginal projection almost at same level as lateral crest; distal end of caudal surface with wide and shallow concavity ( Fig. 7G ). Caudal surface of mesial process with basal lobe, rounded, inconspicuous. In mesial view, caudo-marginal projection with subapical surface of caudal margin slightly excavated; crest of distal lobe broadly rounded; distal lobe broad, triangular, cephalically directed, apex acute, without spine, separated from proximal lobe by wide V-shaped notch; proximal lobe U-shaped notch, length/width ratio 1.4, oblique to principal axis, constrained at base, wider at middle portion, rounded distally ( Fig. 7H ). In cephalic view, distal third slightly inclined laterally, distal and proximal lobes of caudo-marginal projection disposed in same plane, long carina on inner face of proximal lobe, not reaching apex, notably widened ( Fig. 7F ). Mesial process subtriangular, perpendicular to G1 principal axis, ending laterally in acute spine; superior border with long, straight crest reaching inner lobe; inferior border gently convex proximally, concave towards lateral spine; inner lobe subtriangular, subacute, in contact with inner surface of proximal lobe of caudo-marginal projection ( Fig. 7F ). In lateral view, mesial process latero-caudally curved; basal lobe of caudal surface rounded, inconspicuous ( Fig. 7I ). In distal view, apical cavity wide U-shaped; central crest moderately high, slender, reaching inner lobe of mesial process; apical spine field deep, with approximately 30 long spines, disposed in irregular rows; cephalic setae partially covered by superior border of mesial border ( Fig. 7E ). Aperture of spermatic channel in caudal position. Mesial process slightly proximally widened, lateral spine gently curved caudolaterally, long, slender, acute ( Fig. 7E ).

Type locality. The precise locality is still unknown, but according to the original label it is somewhere between the states of Querétaro and México .

Etymology. The specific epithet corresponds to the demonym of Querétaro’s inhabitants “queretano” and “queretana ”; given that Pseudothelphusa is gender femenine, the female form of the demonym is used. The name must be taken as a noun in apposition.

Remarks. The age of the original specimens and the absence of new collection of this taxon mean that DNA evidence for this species is not available. Pseudothelphusa queretana sp. nov. exhibits morphological affinities with P. purhepecha Ojeda-Escoto, Villalobos & Álvarez, 2017 . However, both their disjunct distributions and differences in the G1 morphology between these species (i.e, a mesial process with one lateral spine in P. queretana sp. nov. ( Fig. 7F, G ) versus two lateral spines in P. purhepecha ( Ojeda-Escoto et al., 2017) are enough evidence to recognize them as different. Villalobos-Hiriart (2005) recognized the new species as different from P. americana s. s., however, he did not make any further comments.

Distribution. Pseudothelphusa queretana sp. nov. has not been collected since the last century. Unfortunately, the original label does not include clear information about neither the locality nor the date of the collection, but as far as we can know this species might be found somewhere between the states of Querétaro and México.

Figures

FIGURE 7. Pseudothelphusa queretana sp. nov. holotype (CL 23.33 mm, CW 38.77 mm) (CNCR 342). A, frontal view; B, dorsal view; C, ventral view; D, major chela; E, G1 distal view; F, G1 cephalic view; G, G1 caudal view; H, G1 mesial view; I, G1 lateral view. Abbreviations: ASF, apical spine field; BL, basal lobe; DC, distal crest; DL, distal lobe; LC, lateral crest; MP, mesial process; PL, proximal lobe; SCA, spermatic channel aperture. Scale bars: A–D = 5 mm; E–I = 1 mm.

FIGURE 8. Map of central Mexico showing the distributions of the four Pseudothelphusa species recognized in this study. Localities: 1, Mixquiahuala; 2, Ventoquipa; 3, Michac; 4, Chignahuapan; 5, Zacatlán de las Manzanas; 6, San Miguel La Presa, Ixtacuixtla; 7, La Ascención Huitzcolotepec; 8, ‘El Ojito’ Spring, Apizaco (P. americana s. s. type locality); 9, Palo Huérfano; 10, Cuahutinchán; 11, Cuauxixtla; 12, San Marcos Necoxtla; 13, Ajolotero River, near Chilapa; 14, Querétaro-state of Mexico. State abbreviations: CMX, Mexico City; GUA, Guanajuato; GRO, Guerrero; HID, Hidalgo; MEX, State of Mexico; MIC, Michoacán; MOR, Morelia; OAX, Oaxaca; PUE, Puebla; QUE, Querétaro; TLA, Tlaxcala; VER, Veracruz.