Nilotonia (Telotaolana), 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 : 27-28

Nilotonia (Telotaolana) subgen. nov.

Typus subgeneris: Nilotonia (Telotaolana) ankaratra subgen. nov. sp. nov.

Derivatio nominis: Telo (Malagasy) — three, taolana (Malagasy) — bone; referring to the three large dorsal plates characterising the new subgenus.

Diagnosis: Idiosoma with relatively heavy sclerotization; dorsum with three large plates, covering most of surface; venter with extended secondary sclerotization (males of two species with unified ventral shield), Cx-I medially approximate but not fused, Cx-III mostly medially approximate; Cx-IV form relatively narrow genital bay; suture between Cx-III and Cx-IV incomplete; Vgl-3 very close to caudal margin of Cx-IV; excretory pore without sclerotization; legs without swimming hairs, claws of leg-I to -III with single ventral clawlet (in one species missing) and very tiny (sometimes missing) dorsal clawlet; leg-IV-6 with two small terminal setae and one mid-sized sub-terminal seta (inserted relatively far proximally); capitulum compact with short conical rostrum; sexual dimorphism in degree of sclerotization, with males generally more sclerotized.

Remarks: As the following four new species from Madagascar do not fit in any of the already described subgenera, and at the same time are unified by a characteristic combination of characters, a further new subgenus of Nilotonia is defined to accommodate this species group. The subgenus is mainly unified by the very characteristic arrangement and extent of their dorsal plates, the chaetotaxy of the legs (especially the midsized to relatively large single sub-terminal seta) and the extended secondary sclerotization of the venter. Most African species do not show any secondary sclerotization; only two species from East Africa ( N. violacea and N. loricata ( Nordenskiöld, 1905)) have secondary sclerotization at the posterior margin of Cx-IV and the postgenital sclerite. The pattern of three dorsal plates represents the typical shape of the dorsum of the genus Nilotonia , however the shape and extension (covering most of the dorsum) of the dorsal plates in Nilotonia (Telotaolana) subgen. nov. is unique within the genus. A similar pattern is found in Gilatonia triscutata K.O. Viets, 1974 from Central Africa (K.O. Viets & Böttger 1974), however the genus is clearly different from Nilotonia . An anisitsiellid deutonymph from Southeast-Asia, described as the nymph of Mamersella thienemanni (K. Viets 1935; see also below), is also very similar with Telotaolana subgen. nov. in its dorsal pattern. Cook (1966) describes the presence of three dorsal plates in the deutonymphs as typical for the Anisitsiellidae in general.

All species of Nilotonia (Telotaolana) are represented by very few specimens restricted to their type localities in the Central , Eastern and Southern mountain regions. A further new species, described but not named here, was represented by one deutonymph in the Montagne d’Ambre in Northern Madagascar, and is also placed in this new subgenus .