Nilotonia (Dartiella) ivelany, Goldschmidt, 2008

Goldschmidt, Tom, 2008, Taxonomical, ecological and zoogeographical studies on anisitsiellid water mites (Acari: Hydrachnidia: Anisitsiellidae Koenike, 1910) from Madagascar, Zootaxa 1954 (1), pp. 1-120 : 8-14

Nilotonia (Dartiella) ivelany sp. nov.

( Figs 1–10 , Table 1)

Type series: Holotype male, MD 100 a, Ankaratra (Antananarivo), Reserve Manjakatompo, Montagne Arirana , spring area exposition south-east, drainage Rivière Ambodimangavo, 2200 m asl, 13.5 °C, 1–9 µS/ cm, 05.10.2001, mounted; paratypes, same locality and date, 2/4/0 mounted, 4/17/0 unmounted.

Additional specimens examined: MD 101 , Ankaratra (Antananarivo), Reserve Manjakatompo , stream north-east Andriandahitokana (tributary Rivière Namatoana), 1800 m asl, 15.0 °C, 2 µS/cm, 06.10.2001, 0/1/ 0 mounted ; MD 106 a, Ankaratra (Antananarivo), Reserve Manjakatompo, Montagne Ambohimirandrana , spring area exposition south-east (drainage Rivière Mahiavona), 2300 m asl, 13.4 °C, 4 µS/cm, 07.10.2001, 0/ 2/0 mounted ; MD 171 b, 01.12.2001 Analavory (Antananarivo), Rivière Mazy near Aragonite geyser Carrieres de Monloup , spring outflow, 900 m asl, 23.1 °C, 90 µS/cm (riparian spring: 28.3 °C, 1500 µS/cm), 0/1/0 mounted .

Habitat: Springs at 900–2300 m asl, one stream at 1800 m asl.

Distribution: Madagascar (Central Highlands, mainly Ankaratra mountains (Antananarivo )).

Derivatio nominis: Ivelany (Malagasy) — outside; referring to the position of the genital field, extended far beyond the relatively wide open genital bay.

Diagnosis: Dorsum typical for the genus; integument lined (mainly laterally, medially granular); venter with small areas of secondary sclerotization; Cx-I and Cx-II medial closely approached but not fused, medial length about half of the length of genital field (in females less), suture between Cx-III and Cx-IV incomplete; Cx-III medially Cx-IV medially and caudally with slight secondary sclerotization; genital bay wide; genital field elongated (in males drop-shaped, apically pointed, in females rectangular), acetabula large, oval; posterior genital sclerite in males latero-caudally extended; legs bearing strong setae; claws on leg-I to leg-III with one ventral and one dorsal clawlet, leg-IV distally with one short, thick sub-terminal seta, three short, strong lateral setae, no sexual dimorphism in the legs; palp relatively slender.

Description, male (n = 3): Idiosoma small (L/W 549 (584–589)/402) ( Fig. 1 ); integument dorso-laterally lined, dorso-medially and ventrally rather granular; posterior dorsal plate relatively large (L/W 164 (176– 184)/140 (159–169)), rounded rectangular-oval, posteriorly wider ( Fig. 2 ), anterior dorsal platelets oblique oval (L/W 49 (54–56)/37 (37–44)), one pair of very small knob-shaped sclerites anterior to Dgl–3; glandularia slightly extended, setae of Dgl-4 and -5 larger than all others ( Fig. 2 ); lateral eyes, separated on both sides, lying free under the integument, very close lateral to Dgl–2; Cx-I medially closely approached, but separated ( Fig. 1 ), postero-lateral margin of Cx-II overlapping Cx-III; medial margin of Cx-III extended by fine secondary sclerotization, medial margin of Cx-IV strongly diverging latero-caudally, with cone-shaped caudal corner ( Fig. 1 ), medio- or latero-caudally extended by fine secondary sclerotization ( Fig. 1 ); Cxgl-2 fused with Cx-III, Cxgl-4 closely approached to the anterior margin of Cx-III ( Fig. 1 ); genital field lying in wide genital bay mainly posterior to coxal field ( Fig. 1 ), genital flaps large, anteriorly tapering, caudally broadened ( Fig.1 ); acetabula large (L/W 39–49 (44–51)/18–22 (20–22) oval, touching each other, Ac1 slightly distant from anterior margin of genital flaps ( Fig. 1 ); anterior genital sclerite small, bowed with medial bump ( Fig. 1 ), posterior genital sclerite large, crescent-shaped, broader than genital field, caudal margin fine, irregular ( Fig. 1 ); excretory pore without sclerotization; Vgl slightly extended by secondary sclerotization, four small, irregular platelets on a curved line parallel the caudal margin of idiosoma ( Fig. 1 ); legs bearing several large setae (several pinnate, distally mostly flatly broadened); claws on leg-I to leg-III well developed with one small dorsal and one larger ventral clawlet ( Fig. 3 ), leg-IV-6 distally tapering with one relatively small, slightly pinnate sub-terminal seta ( Fig. 4 ); capitulum compact, ventrally straight, no distinct rostrum ( Fig. 5 ), palps relatively slender ( Figs 5, 6 ), P1 with one small dorsal seta, P2 with one relatively short latero-ventral seta and five to six dorsal setae, ventral margin straight, P3 with two latero-dorsal and two latero-medial fine setae, ventral margin curved, P4 slender, relatively straight, ventro-distally slightly curved ventral setae slightly distal on very weak protrusions ( Figs 5, 6 ), chelicera with strong, slightly curved claw ( Fig. 7 ).

Female (n = 8): Posterior dorsal plate nearly rounded ( Fig. 9 ); idiosoma larger (L/W 579-736/432-589) ( Fig. 8 ); Cx-IV and genital field more elongated than in males; genital flaps straight, anterior genital sclerite larger, more triangular, posterior genital sclerite smaller, bowed with medial bump, not protruding beyond genital field ( Fig. 8 ); no significant sexual dimorphism in legs, distal segments of leg-II slightly more elongated than in males ( Fig. 10 ); gnathosoma as in male.

Remarks: See next species below.

Figures

FIGURES 1–7. Nilotonia (Dartiella) ivelany sp. nov., male holotype (MD 100a): 1, idiosoma, ventral view; 2, idiosoma, dorsal view; 3, leg-II; 4, leg-IV (first segment broken); 5, capitulum with left palp, lateral view; 6, right palp, medial view; 7, chelicera, lateral view. Scale bars = 100 µm.

FIGURES 8–10. Nilotonia (Dartiella) ivelany sp. nov., female paratype (MD 100a): 8, idiosoma, ventral view; 9, idiosoma, dorsal view; 10, leg-II. Scale bar = 100 µm.