Arrenurus (Truncaturus) minutus Smit & Pesic, 2006, spec. nov.

Arrenurus (Truncaturus) minutus spec. nov.

(Figs. 13–16)

Material examined: Holotype: Male, IR82, Gilan Province, Bandar Anzali Lagoon, 16 June 2005, leg. Pesic (MNHP). Paratypes: 1 male (ZMAN), 2 females (ZMAN, MNHP), same data as holotype.

Description

Male: Idiosoma 575 (602) µm long and 413 (421) µm wide. Dorsal shield incomplete, 300 µm wide. Posterior margin of idiosoma with a very faint indentation. D4 close to posterior end of dorsal furrow. Genital plates almost four times as long as wide, not reaching to lateral idiosoma margin. Lengths of PI­PV: 26, 48, 38, 58, 33; PII with two medial setae. Lengths of I­leg­4­6: 84, 86, 86. Lengths of IV­leg­4­6: 96, 108, 106; IV­leg­ 4 without a spur. Third and fourth legs with numerous swimming setae.

Female: Idiosoma 725 (680) µm long and 579 (535) µm wide. Idiosoma egg­shaped, anterior margin convex, posterolateral corners absent. Dorsal shield complete, 575 µm long and 433 µm wide. Medial margins of fourth coxal plates longer than medial margins of third coxal plates. Medial distance of fourth coxal plates a little bit less than width of two genital valves. Genital field located halfway between posterior margin of fourth coxal plates and posterior idiosoma margin. Genital plates short and broad. Lengths of PI­PV: 26, 56, 43, 65, 38; palp as in male. Lengths of I­leg­4­6: 96, 108, 95. Lengths of IV­leg­4­ 6: 130, 140, 126. Third and fourth legs with numerous swimming setae. Etymology: Named for its small size.

Remarks: The small size and the shape of the idiosoma almost without an indentation are diagnostic for the new species.