Published October 23, 2025 | Version v1
Taxonomic treatment Open

Raddaus mertensi Sur

  • 1. Laboratório de Bioecologia e Sistemática de Crustáceos (LBSC), Departamento de Biologia, Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto (FFCLRP), Universidade de São Paulo (USP), Avenida Bandeirantes, 3900; 14040 - 901, Ribeirão Preto, SP (Brazil) and Instituto Nacional de Pesquisas da Amazônia, Avenida André Araújo 2936, 69067 - 375 Manaus, Amazonas (Brazil)
  • 2. Museo de Zoología of the Centro de Investigación en Biodiversidad y Ecología Tropical (CIBET), Universidad de Costa Rica, 11501 - 2060 San José (Costa Rica) Unidad de Investigación Pesquera y Acuicultura (UNIP) of the Centro de Investigación de Ciencias del Mar y Limnología (CIMAR), Universidad de Costa Rica, 11501 - 2060 San José (Costa Rica) and Editorial Universitaria, Universidad del Valle de Guatemala, 18 Avenida 11 - 95, Zonas 15, Vista Hermosa III, Ciudad de Guatemala (Guatemala)

Description

Raddaus mertensi (Bott, 1956)

(Figs 6D, E; 16)

Pseudothelphusa cobanensis mertensi Bott, 1956: 231, pl. 30, fig. 3ac, pl. 35, fig. 3a, b.

Raddaus mertensi – Cumberlidge et al. 2014: 147 (in table). — Wehrtmann et al. 2016: 781 (in list). — Acevedo-Alonso & Cumberlidge 2022: 583 (Appendix 2, in list).

TYPE MATERIAL EXAMINED. — Holotype. El Salvador • 1♂ (37.3:24.4); Santa Ana, Los Planes Farm [northeast of Metapán, Montecristo National Park; 14°24’N, 89°22’W]; 1830 m elev.; 30.X.1950; R. Mertens leg.; SMF 1822.

OTHER MATERIAL EXAMINED. — Guatemala • 1 ♂ (soft carapace) 3 juv. ♀; Chiquimula, Río Atulapa, 3 miles east of Esquipulas, on road CA 10; [14°33’45”N, 89°18’37”W; 916 m elev.]; 5.IV.1971; R. M. Bailey leg.; USNM 1089229.

DISTRIBUTION. — Guatemala (Chiquimula) (Fig. 16), Honduras (Ocotepeque) and El Salvador (Santa Ana) (Bott 1956; Wehrtmann et al. 2016; Acevedo-Alonso & Cumberlidge 2022; Magalhães & Wehrtmann 2025; this study).

DESCRIPTION OF G1 (Fig. 6D, E)

Stout, straight in mesial view, narrow in proximal 2/3, very wide in distal third, moderately compressed mesolaterally; caudal and cephalic margins straight in mesial view. Marginal suture on mesial surface straight up to apex along most of stem, slightly curved in caudal direction in distal quarter, with short row of large marginal setae along proximal portion. Marginal process somewhat narrow, rounded, not extending beyond mesial margin of apex. Lateral suture incomplete, marked by shallow sulcus on caudal surface. Mesial process greatly widened, slightly wider (roughly 1.2 times) than main stem, subretangular, directed cephalad, bilobed, with proximal lobe bearing broadly subtriangular teeth pointing basally; distal lobe as narrow subtriangular teeth slightly shorter than proximal lobe in mesial view; mesial lobe with proximal margin bearing short row of minute setae; distal margin slightly crenulate, cephalic surface slightly concave in lateral view, bearing strong triangular, subdistal spine pointing cephalad, and small, rounded protuberance located just below subdistal spine.Apex oblong, short, situated obliquely, open, mesial slightly higher than lateral one; field of apical spines moderately developed, with short small spines; spermatic channel opening on apex cavity, situated towards caudal end.

REMARKS

This species was known only from its type locality, in the department of Santa Ana, in northwestern El Salvador. Later, Acevedo-Alonso & Cumberlidge (2022) listed the occurrence of this species in Guatemala and Honduras without specifying voucher material or distributional data. Thus, our report herein represents the first published record of this species for Guatemala.

Notes

Published as part of 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, pp. 581-615 in Zoosystema 47 (26) on page 600, DOI: 10.5252/zoosystema2025v47a26, http://zenodo.org/record/17432059

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Linked records

Additional details

Biodiversity

Collection code
SMF , USNM
Material sample ID
SMF 1822 , USNM 1089229
Event date
1950-10-30 , 1971-04-05
Verbatim event date
1950-10-30 , 1971-04-05
Scientific name authorship
Sur
Kingdom
Animalia
Phylum
Arthropoda
Order
Decapoda
Family
Pseudothelphusidae
Genus
Raddaus
Species
mertensi
Taxon rank
species
Type status
holotype
Taxonomic concept label
Raddaus mertensi (Bott, 1956) sec. Magalhães & Wehrtmann, 2025

References

  • BOTT R. 1956. - Dekapoden (Crustacea) aus El Salvador. 3. Susswasserkrabben (Pseudothelphusa). Senckenbergiana biologica 37 (3 / 4): 229-242. https://decapoda.nhm.org/pdfs/26965/26965.pdf
  • CUMBERLIDGE N., ALVAREZ F. & VILLALOBOS J. L. 2014. - Results of the global conservation assessment of the freshwater crabs (Brachyura, Pseudothelphusidae and Trichodactylidae): the Neotropical region, with an update on diversity. ZooKeys 457: 133-157. https://doi.org/10.3897/zookeys.457.6598
  • WEHRTMANN I. S., MAGALHAES C. & OROZCO M. N. 2016. - An update on the primary freshwater crab fauna of Guatemala (Decapoda, Brachyura, Pseudothelphusidae). Journal Crustacean Biology 36 (6): 776-784. https://doi.org/10.1163/1937240X-00002478
  • ACEVEDO-ALONSO A. & CUMBERLIDGE N. 2022. - Conservation status of the neotropical mountain freshwater crabs (Pseudothelphusoidea), in DellaSala D. A. & Goldstein M. I. (eds), Imperiled: The Encyclopedia of Conservation. Volume 2. Elsevier, Amsterdam: 564-589. https://doi.org/10.1016/B978-0-12-821139-7.00091-X
  • MAGALHAES C. & WEHRTMANN I. S. 2025. - Diversity of freshwater crab: new distributional data for four species (Decapoda: Pseudothelphusidae) from Meso- and South American countries. Revista de Biologia Tropical 73 (S 1): e 63625. https://doi.org/10.15517/rev.biol.trop..v73iS1.63625