Hydrothelphusa

Cumberlidge, Neil, Marijnissen, Saskia A. E. & Thompson, Jonelle, 2007, Hydrothelphusa vencesi, a new species of freshwater crab (Brachyura: Potamoidea: Potamonautidae) from southeastern Madagascar., Zootaxa 1524, pp. 61-68 : 67

Key to the species of Hydrothelphusa

1 Inferior margins of merus of pereiopod 1 with either large teeth or large granules; anterior carapace texture distinctly granular with short carinae. .................................................................................................. 2

- Inferior margins of merus of pereiopod 1 either smooth or faintly granular; anterior carapace texture completely smooth.............................................................................................................................................. 4

2 Frontal margin clearly toothed; front horizontal (not deflexed); suborbital margin with large pointed teeth; suborbital region of carapace sidewall smooth (Cumberlidge & Sternberg 2002: Fig. 1 A). ........................ ......................................................................................................................................................... H. agilis

- Frontal margin granular; front moderately deflexed; suborbital margin granular; suborbital region of carapace sidewall granular. ................................................................................................................................ 3

3 Subhepatic regions of carapace sidewall heavily granulated. .................................... H. madagascariensis

- Subhepatic region of carapace sidewall smooth. ....................................................................... H. vencesi

4 Exorbital, epibranchial teeth both slim, long, pointed; distinct gap between epigastric, postorbital crests (Cumberlidge & Sternberg 2002: Fig. 1 C). ................................................................... H. bombetokensis

- Exorbital, epibranchial teeth both low, blunt; epigastric, postorbital crests fused forming horizontal postfrontal crest (Cumberlidge & Sternberg 2002: Fig. 1 D). ........................................................... H. goudoti

Figures

FIGURES 1 – 9. Hydrothelphsua vencesi n. sp., adult male holotype (cw 52 mm, ZMA De. 205976) from Vevembe, Fianarantsoa Province, Madagascar. 1, carapace and eyes, dorsal view; 2, cephalothorax, carapace and eyes, frontal view; 3, right cheliped, frontal view; 4, left cheliped, frontal view; 5, carpus and merus of right cheliped, dorsal view; 6, merus of right cheliped, inferior view; 7, left third maxilliped; 8, sternum and abdomen; 9, abdomen pulled back to show first and second gonopods. Scale = 13 mm (1,2, 8, 9); 7 mm (3 – 7).