Axonopsis (Axonopsis) hyporheica, Pešić & Smit & Saboori, 2012

Pešić, Vladimir, Smit, Harry & Saboori, Alireza, 2012, 3330, Zootaxa 3330, pp. 1-67 : 52-54

Axonopsis (Axonopsis) hyporheica sp. nov.

( Figs. 38A – H)

Material examined. Holotype male, dissected and slide mounted, Iran, Hormozgan Province, IR22-2011, Rudan city N of Bandar Abbass, 5 km N of Rudan, Rudan stream, upstream, interstitial dig, 27º 28.748 N, 57º 15.648 E, 210 m asl, 21.vii.2011 ( RMNH) . Paratypes: 2/3/0 (0/2/0 mounted), same data as holotype, interstitial dig; 3/2/0 , same data as holotype, interstitial (pump); 0/1/0 , same data as holotype, surface water sample (all RMNH) .

Diagnosis. Idiosoma relatively elongated (L/W ratio 1.7 – 1.9); dorsal furrow on each side in the posterior part with one short and one elongate glandular platelet and two free slit organs not fused with the neighbouring glandular platelets. Palp: P-4 relatively long (L P-2/P-4 ratio 0.65), proximally and distally narrowed, in the middle of ventral margin expanded, with two short setae, inserted side by side; II-, III- and IV-L with swimming setae.

Description. Male (holotype, in parentheses measurements of paratypes) — Dorsal and ventral shield anteriorly fused; dorsal shield ( Fig. 38A) L/W 384 (379 – 386)/213 (189 – 192), with four pairs of small glandularia (the fourth pair inconspicuous, flanking the excretory pore); postocularia well distanced from anterior margin; colour pattern indistinct; eye pigment developed. Dorsal furrow on each side, from anterior to posterior, bearing: one slit organ slightly posterior to the centre of idiosoma, a short glandularium platelet, a second pair of slit organs and an elongate glandularium platelet. Excretory pore located at posterior end of dorsal shield. Ventral shield ( Fig. 38B) L/ W 415 (412 – 413)/219 (213 – 217), with subparallel lateral margins; distal margin of Cx-I projecting beyond the strong concave frontal margin; lateral margins of Cx-I and -II without hook-like projections, forming a slightly undulating line, Cx-II/III not prominent. Gnathosomal bay L 105. Venter without a ridge on each side extending posteriorly from the region of insertion of the IV-L. Genital field distinctly set off from the remainder of the ventral shield. Four pairs of Ac arranged in two anterior and two posterior pairs; distance between most lateral pair of Ac 95; gonopore narrow W 13. A pair of slit organs and a pair of seta-bearing platelets lying in the soft integument posterior to the ventral shield. Ejaculatory complex ( Fig. 38E) L 155. Palp ( Fig. 38F): total L 189, dL: P-1, 21; P-2, 46; P-3, 26; P-4, 71; P-5, 25; L P-2/P-4 ratio, 0.65; P-2 stout, ventral margin nearly straight, P-3 with dorsal margin equally convex, distal margins forming sheets flanking the insertion of the subsequent segment; P-4 proximally and distally narrowed, middle of ventral margin expanded, with two short setae, inserting side by side; P-5 relatively long, inserted between weakly convex lateral and medial projections of P-4. Gnathosoma vL 70, chelicera total L 101. Legs: dL of I-L-5-6 ( Fig. 38G): 50, 72; dL of IV-L: 40, 55, 46, 68, 75, 80; IV-L-2/3 distally with pointed sheaths covering the base of the following segment ( Fig. 38H); swimming setae numbers: II-L-5, 2; III-L-4, 1; III- L-5, 2; IV-L-4, 1; IV-L-5, 2.

Female (paratypes, n = 2) — Similar to male except for the shape of the genital field ( Fig. 38D). Dorsal shield L/W 394/209; ventral shield L/W 408 – 409/242; gnathosomal bay L 100 – 107. Distance between most lateral pair of Ac 103 – 112; gonopore W 23 – 27. Palp: total L 200, dL: P-1, 21; P-2, 48; P-3, 29; P-4, 74; P-5, 28; L P-2/P-4 ratio, 0.65. Gnathosoma vL 75 – 79, chelicera total L 97. Legs: dL of I-L-3–6: 43 – 46, 46 – 49, 63 – 66; dL of IV-L: 39 – 42, 51 – 56, 47 – 48, 64 – 65, 69 – 73, 74; palp chaetotaxy and swimming setae numbers as in male.

Etymology. The species is named for its occurrence in hyporheic habitat.

Remarks. Due to the comparatively long and slender idiosoma and the lack of colour pattern, Axonopsis hyporheica sp. nov., most closely resembles A. phreaticola Cook, 1967 , a hyporheobiontic species known from Maharashtra State in India ( Cook 1967, Pešić & Ranga Reddy 2009).

The new species differs from A. phreaticola (in the following, in parentheses measurements taken from Cook 1967) in its slightly smaller size, the second pair of slit-organs not fused (fused to posterior margin of anterior glandular platelets in the species from India, see Cook 1967: Fig. 631), and in a more slender and relatively longer P-4 (stouter and relatively shorter, see Cook, 1967: Fig. 629; L P-4 59-65 µm in both sexes, L P-2/P-4 ratio 0.84-0.85).

Habitat. Interstitial waters associated with sand and gravel deposits of a stream.

Distribution. Iran; only known from interstitial waters in Hormozgan Province.