Arrenurus (Megaluracarus) glaucus, Smit, Harry, 2010

Smit, Harry, 2010, Australian Arrenurus (Acari, Hydrachnidia) with the description of eleven new species, Zootaxa 2541, pp. 1-26 : 7

Arrenurus (Megaluracarus) glaucus n. sp.

( Figs. 4A–D )

Material examined. Holotype male, Murray River at entrance Lane Pool Reserve, Western Australia, Australia, 32° 46’ 5.27” S 116° 4’ 47.64” E, 25 April 2008 ( WAM). Paratypes: 2/1/0, same data as holotype ( WAM); 2/4/0, Kent River at crossing with South Coast Highway, Western Australia, Australia, 34° 57.576 S 117° 0 2.430 E, 19 April 2008 ( ZMAN)

Diagnosis. Male with a posteriorly rounded cauda, idiosoma colour conspicuously blue; PII without a patch of setae.

Description. Male: Idiosoma conspicuously blue, 850 (834–1004) long and 478 (482–494) wide; anterior idiosoma margin straight. Dorsal shield incomplete, 336 (328–332) wide. D4 on small humps. Cauda posterolaterally with an indentation, cauda posteriorly rounded or with a very shallow indentation. Setae between D4 and posterior cauda margin bifurcated ( Fig. 4A ). Anterior coxae not extending to anterior idiosoma margin. Gonopore 56 long. Genital plates long and narrow, extending to lateral idiosoma margin ( Fig. 4B ). Lengths of PI-PV: 22, 60, 50, 70, 31; PII with four setae medially, three setae anteroventrally and one inserted more dorsally ( Fig. 4C ). Lengths of I-leg-4-6: 108, 114, 110. Lengths of IV-leg-4-6: 144, 148, 162; IV-leg-4 with a short, triangular spur. Third and fourth legs with numerous swimming setae, second leg with much less swimming setae and first leg with only a few swimming setae.

Female: Idiosoma 927 (806–907) long and 713 (591–697) wide, colour as in the male. Anterior idiosoma margin straight. Dorsal shield complete, 770 (632–713) long and 567 (437–531) wide. Anterior coxae not extending to anterior idiosoma margin. Medial margin of fourth coxal plates larger than medial margin of third coxal plates. Distance of fourth coxal plates smaller than with of one genital valve. Gonopore 130 long and 144 wide. Gonopore anteriorly with a triangular chitinized patch, posteriorly with only a small chitinized patch; anterior and posterior chitinized patch medially connected by a small strip ( Fig. 4D ). Genital field 365 wide, genital plates short, broad and rounded laterally. Lengths of PI-PV: 32, 74, 52, 76, 40; palp as in male. Lengths of I-leg-4-6: 114, 126, 104. Lengths of IV-leg-4-6: 168, 166, 136. Swimming setae as in male.

Etymology. Named for the conspicuous light-blue colour.

Remarks. The combination of an almost posteriorly rounded cauda, absence of a patch of setae on PII and the conspicuously blue colour are diagnostic for the new species.

Figures

FIGURE 4 A – D. Arrenurus glaucus n. sp., (A – C holotype male, D paratype female): A = dorsal view; B = ventral view; C = palp; D = ventral view. Scale bars A – B, D = 200 µm; C = 50 µm.