Himalayapotamon

Pati, S. K. & Singh, S., 2017, A new species of freshwater crab of the genus Himalayapotamon Pretzmann, 1966 (Decapoda, Brachyura: Potamidae: Potaminae) from Uttarakhand, northern India, Zootaxa 4237 (1), pp. 191-200 : 198-199

Key to the species of Himalayapotamon

1. Sixth male abdominal somite short, median length nearly two-fifth greatest width ( Fig. 5C )..........................2

- Sixth male abdominal somite long, median length nearly half greatest width ( Figs. 2 C, 5D)......................... 3

2. G1 terminal joint conical, with tip slightly curved outwards ( Fig. 5 E)............................................................................................. H. bifarium ( Alcock, 1909) [ INDIA (Sikkim)? or MYANMAR?]

- G1 terminal joint S-shaped ( Fig. 5 F)............... H. monticola ( Alcock, 1910) [ INDIA (Meghalaya and West Bengal)]

3. Male telson with acute apex (see Pretzmann 1966: pl. 3, fig. 11)..................................................................................................... H. kasaulis ( Pretzmann, 1966) [ INDIA (Himachal Pradesh)]

- Male telson with rounded apex ( Figs. 2 C, 5D)............................................................. 4

4. Epigastric and postorbital cristae separated by indistinct groove ( Fig. 5B )............................................................................................... H. ambivium ( Alcock, 1909) [ INDIA (Himachal Pradesh)]

- Epigastric and postorbital cristae separated by distinct groove ( Fig. 2 A)......................................... 5

5. G1 terminal joint sinuous (see Brandis 2001: fig. 3c).................................................................... H. atkinsonianum (Wood-Mason, 1871) [ BHUTAN, INDIA (Meghalaya, Sikkim and West Bengal) and NEPAL]

- G1 terminal joint conical, with almost straight margins ( Fig. 3 A)............................................... 6

6. G1 terminal joint slender (see Brandis 2001: fig. 4c)......................................................... 7

- G1 terminal joint stout ( Fig. 3 A)......................................................................... 9

7. G1 terminal joint blunt towards tip (see Brandis 2001: fig. 4c).................................................... H. emphyseteum ( Alcock, 1909) [ INDIA (Himachal Pradesh, Jammu and Kashmir and Uttarakhand), NEPAL and PAKISTAN]

- G1 terminal joint distinctly narrowing towards tip (see Bott 1970: pl. 38, fig. 19).................................. 8

8. G1 terminal joint short, ca. 0.3 times length of subterminal joint (see Bott 1970: pl. 38, fig. 19)............................................. H. koolooense ( Rathbun, 1904) [ AFGHANISTAN, INDIA (Himachal Pradesh, Meghalaya, Sikkim, Uttar Pradesh, Uttarakhand and West Bengal) and NEPAL]

- G1 terminal joint long, ca. 0.4 times length of subterminal joint (see Brandis & Sharma 2005: fig. 5C).............................................................................. H. sunkoshiense Brandis & Sharma, 2005 [ NEPAL]

9. G1 terminal joint suddenly tapers distally (see Bouvier 1918: fig. 10I).................................................................................................. H. babaulti ( Bouvier, 1918) [ INDIA (Himachal Pradesh)]

- G1 terminal joint gradually tapers distally ( Fig. 3 B).........................................................10

10. Postorbital cristae almost straight (see Pretzmann 1963: pl. 1, fig. 1); male telson with straight lateral margins (see Pretzmann 1963: pl. 1, fig. 4); G1 terminal joint long, ca. 0.3 times combined length of subterminal joint and flexible zone (see Pretzmann 1963: pl. 3, fig. 11)........................................ H. marinellii ( Pretzmann, 1963) [ INDIA (West Bengal)]

- Postorbital cristae distinctly curved ( Fig. 2 A); male telson with concave lateral margins ( Fig. 2 C); G1 terminal joint short, ca. 0.2 times combined length of subterminal joint and flexible zone ( Fig. 3 A).... H. garhwalense n. sp. [ INDIA (Uttarakhand)]

Figures

FIGURE 2. Himalayapotamon garhwalense n. sp., holotype male (ZSI, WRC-C. 1178). A, dorsal view; B, frontal view; C, ventral view. Scale bar = 10 mm.

FIGURE 3. Himalayapotamon garhwalense n. sp., holotype male (ZSI, WRC-C. 1178). A, dorsal view of right G 1; B, dorsal view of right G 1 terminal joint; C, ventral view of right G 1; D, right G 2. Scale bar = 1 mm.

FIGURE 5. A, C, F, Himalayapotamon monticola (Alcock, 1910), male (21.38 × 17.44 mm) (ZSI, Kolkata-C. 4315 / 2), B, D, Himalayapotamon ambivium (Alcock, 1909), syntype, male (14.88 × 11.68 mm) (ZSI, Kolkata- 5436 / 10), E, Himalayapotamon bifarium (Alcock, 1909), syntype, male (ZSI, Kolkata- 5512 / 10). A, B, dorsal view; C, D, ventral view; E, dorsal view of left G 1; F, dorsal view of right G 1. Scale bar = 1 mm.