Xystonotus madagascariensis Pešić, Cook & Gerecke, 2013

Pešić, Vladimir, Cook, David, Gerecke, Reinhard & Smit, Harry, 2013, The water mite family Mideopsidae (Acari: Hydrachnidia): a contribution to the diversity in the Afrotropical region and taxonomic changes above species level, Zootaxa 3720 (1), pp. 1-75 : 69-75

Xystonotus madagascariensis Pešić, Cook & Gerecke sp. nov.

( Figs. 41G–H , 44A–F )

Type series: Holotype female, dissected and slide mounted, Madagascar 109, Ankaratra (Antananarivo), Reserve Manjakatompo, riparian spring exp. SE, at spring stream N deviation to Analamitana (MD108), 1850 m asl., 14.3˚C, 0.003 mS/cm, 08.x.2001, Gerecke & Goldschmidt. Paratype: same locality and data as holotype, 0/1/0 (dissected and slide mounted).

Diagnosis (based on female; male unknown). Dorsal shield with V-shaped area of smaller pores only slightly raised laterally, reaching frontal and caudal margin of dorsal shield, more distanced to each other in their middle part, leaving a broader medial, and narrower lateral areas ( Figs. 41 G-H); gnathosomal bay a rounded V-shaped; medial margin of Cx-IV reduced to a median angle; genital bay of moderate depth, embracing approximately onehalf of the genital field ( Fig. 44E ); genital field noticeably wider than long (L/W ratio 0.9); Cxgl-2 located anterior to gonopore; ventral tubercle of P-4 truncate.

Description

Female (holotype, in parentheses measurements of paratype): Idiosoma (ventral view: Fig. 44B ) L/W 434 (475)/378 (394). Dorsal shield ( Fig. 41 G-H) L/W 398 (428)/341 (347), ratio 1.17 (1.23); gnathosomal bay L 65 (65); gonopore L/W 83 (86)/94 (92), ratio 0.9 (0.9); egg maximum diameter (127). Palp ( Fig. 44C ): total L 165-167 (163); L/H, L/H ratio: P-1, 20/25, 0.8 (20/25, 0.8); P-2, 39/40, 0.98 (37/40, 0.93); P-3, 35/31, 1.12 (32/32, 1.0); P- 4, 52-53/28-29, 1.9 (55/28, 2.0); P-5, 19-20/10, 2.0 (19/9, 2.1); chelicera total L 92 (89); gnathosoma vL 82 (80). Legs: dL of I-L: 60 (59), 59 (59), 45 (48), 50 (51), 63 (65), 77 (74); I-L-6 H 36 (33), I-L-6 dL/H ratio 2.1 (2.2); dL of IV-L: 69 (72), 60 (71), 59)63), 79 (83), 99 (103), 92 (105).

Male: Unknown.

Etymology: Named after the country of the type locality.

Discussion: Due to the shape of the posteromedial suture lines of Cx-IV which extend abruptly posteriorly and closely flank the genital field, the new species is assigned to the subgenus Mixomideopsis which also includes Xystonotus (Mixomideopsis) sandola (Cook) from South Africa. The later species is unique within the genus Xystonotus in that the legs bear a few swimming setae (numbers: III-L-3/4 and IV-L-4, 1, III/IV-L-5, 2), Cxgl-2 being located close to anterolateral margin of genital field, and P-4 very slender with a proximally placed ventral tubercle.

Distribution: Madagascar; only known from the type locality in the Ankaratra mountains.

Figures

FIGURE 41 A – H. Photographs of dorsal shield. A – C. Djeboa multidentata K. Viets, 1911: A — male holotype (SMF 43185); B – C — male (SMF 43203). D – E. Mideopsellides geae K. O. Viets, 1962: D — male holotype; E— female paratype; F. Phreatomideopsis arrenuripalpis Schwoerbel, 1986: lectotype female. G – H. Xystonotus madagascariensis sp. nov., female: G = holotype; H = paratype.

FIGURE 44 A – F. Xystonotus madagascariensis sp. nov., female: A = dorsal shield; B = idiosoma, ventral view; C = palp; D = palp, chelicera and gnathosoma; E = genital field; F = I-L; G = IV-L.