Hygrobates (Hygrobates) hamatus K. Viets, 1935

Pešić, Vladimir, Smit, Harry & Saboori, Alireza, 2012, 3330, Zootaxa 3330, pp. 1-67 : 33

Hygrobates (Hygrobates) hamatus K. Viets, 1935

( Fig. 23A – C)

Material. Iran, Hormozgan Province, IR22-2011, 5 km N of Rudan N of Bandar Abbass, Rudan stream, 27º 28.748 N, 57º 15.648 E, 210 m asl, 21.vii.2011 0/1/0 (mounted) .

Morphology. Female — Idiosoma L/W 931/669; dorsum without plates. Coxal field: Cx-I very long. Gnathosoma relatively small and broadly fused at base. Posterior apodemes of Cx-I+II moderately developed, suture line between Cx-III+IV complete, ending at bluntly-pointed medial margin of Cx-III+IV; posterior margin of Cx-IV with moderately developed projections; coxal field L 372, Cx-III W 416. Genital field L/W 136/164; genital plate narrow, L 87-92; egg (n = 2) maximum diameter 153. Palp ( Fig. 23C): total L 520, dL: P-1, 30; P-2, 142; P-3, 131; P-4, 188; P-5, 29; L P-2/P-4 ratio, 0.76; ventral margin of P-2 and P-3 with numerous small papillae, P-2 and P-3 swollen. Chelicera total L 287. Legs: dL of I-L-2-6 ( Fig. 23B): 108, 136, 172, 185, 156; dL of IV-L: 141, 144, 231, 286, 325, 265.

Remarks. The single specimen from Hormozgan province is provisionally assigned to the Oriental Hygrobates hamatus . It resembles both Hygrobates hamatus and the Afrotropical H. soari K. Viets, 1911 . Cook (1967) described H. hamatus bharatensis Cook, 1967 , from India and stated that this subspecies differs from the stem species in having much smaller projections on the posterior margin of Cx-IV. Later on, Gledhill & Wiles (1997) synonymized this subspecies with the stem species which is widespread in the Oriental region (Pešić et al. 2010) and furthermore reported from New Guinea and Australia ( Wiles 1997c, Cook 1986). Hygrobates hamatus is very similar to H. soari K. Viets, 1911 , a species widspread in the Afrotropical region, reaching in its distribution to northern Oman ( Gerecke 2004b, Smit & Pešić 2010). The diagnostic differences separating these two species have been discussed only by Cook (1967) who mentioned that the anterior coxal group is much shorter in H. hamatus bharatensis . More material should be studied in order to get an insight into further diagnostic differences. Similar to Diplodontus silvestrii and D. schaubi , this probably will require applying molecular techniques.

Habitat. Sandy/bouldery stream, with strong exposure to sunlight ( Fig. 44D).