Diplodontus silvestrii (Daday, 1898)

Pešić, Vladimir, Smit, Harry & Saboori, Alireza, 2012, 3330, Zootaxa 3330, pp. 1-67 : 12-13

Diplodontus silvestrii (Daday, 1898)

( Figs. 7A–C)

Material examined. Iran, Sistan va Baluchestan Province, IR5-2011, Gerdoig village N of Chabahar, 5 km of Koch village , pool, 25º 46.084 N, 60º 54.968 E, 13.vii.2011 25/2 (1/1/0 mounted) .

Morphology. Male — Idiosoma L/W 1270/1080; integument without sclerotized muscle insertions; Coxal field: medial subcutaneous extensions of Cx-I+II in their distal parts bent caudally ( Fig. 7A); L Cx-I+II 222, Cx- III+IV 381. Genital field: L/W 188/294, with triangular genital plates, maximum W at posterior margin, medial setae on genital plates regularly arranged along medial margin, a few longer setae concentrated near the posteromedial margin. Palp ( Fig. 7C) stout: total L 332; dL (in parentheses dL/H ratio): P-1, 39 (0.63); P-2, 85 (1.32); P-3, 60 (0.95); P-4, 117 (2.66); P-5, 31 (2.0); P-2 with three to five long and strong medial setae; L chelicera 366, basal segment 253, claw 134, L ratio basal segment/claw 1.89. Legs: dL of IV-L: 120, 111, 175, 231, 239, 206; swimming setae numbers: II-L-5, 10; III-L-4, 12; III-L-5, 15; IV-L-3, 1; IV-L-4, 17; IV-L-5, 13.

Female — Idiosoma L/W 1450/1200; coxal field: Cx-I+II 259, Cx-III+IV 415. Genital field L/W 222/334. Palp: total L 416; dL (in parentheses dL/H ratio): P-1, 52 (0.68); P-2, 101 (1.34); P-3, 78 (0.98); P-4, 149 (2.85); P- 5, 36 (1.8); L chelicera ( Fig. 7B) 459, basal segment 316, claw 170, L ratio basal segment/claw 1.86. Legs: dL of IV-L: 153, 150, 222, 303, 303, 234; swimming setae numbers: II-L-5, 10; III-L-4, 8; III-L-5, 15; IV-L-3, 1; IV-L-4, 16; IV-L-5, 13-15.

Remarks. The specimens from Sistan va Baluchestan are provisionally assigned to the Oriental species Diplodontus silvestrii . However, they resemble both Diplodontus silvestrii and the Afrotropical D. schaubi (Koenike, 1893) . According to Gerecke (2004a), with the present state of knowledge, D. silvestrii differs from D. schaubi in a shorter cheliceral claw (L ratio basal segment/claw> 1.9, D. schaubi <1.9). The specimens from Sistan va Baluchestan agree in most dimensions with the measurements of D. silvestrii given by Cook (1967) for a single male specimen from India, as well with D. schaubi , a species widespread in standing waters in the Afrotropical region ( Gerecke 2004a). Our specimens differ from both D. schaubi and D. silvestrii in a stouter P-4 (L/H 2.7 – 2.9, in the compared species 2.9 – 3.3). As Gerecke (2004a) noted, the diagnostic features and taxonomic relationship of the Asian species require further revision. This should include the relationship with species from other zoogeographical regions, with emphasis to populations from the transitional area, what probably will require applying molecular techniques.

Habitat. Standing water ( Fig. 8A)