Moramangabates, Gerecke, 2004

Gerecke, Reinhard, 2004, The water mites of Madagascar (Acari, Hydrachnidia): a revised list completed by original material conserved at the Muséum national d’Histoire naturelle, Paris, Zoosystema 26 (3), pp. 393-418 : 400-401

Moramangabates n. gen.

TYPE SPECIES. — Moramangabates pauliani n. sp.

ETYMOLOGY. — Combining the name of the area where the holotype of the type species was collected with the suffix -bates (Greek: walking), often employed for Hygrobates -like genera.

DIAGNOSIS. — Female (male unknown): characters of the family Hygrobatidae ; no fusion between coxae and gnathosoma; gnathosoma with a long caudal projection extending between the medial margins of the anterior coxal plates; apodeme at the projecting posterior margin of cx-4 distinct, but not continuing as a sclerotized line to the glandular opening on this coxa; genital field with 13 pairs of acetabula; P-2 with a ventrodistal projection, P-3 with a ventral hump; legs provided with long, stiff setae at the distal margins, and partly also on the ventral surface, of segments 2-5.

DISCUSSION

This new taxon is most closely related to Australiobates Lundblad, 1941 , a genus with a typical Gondwanan distribution including South America, South Africa, Australia, New Zealand and Papua New Guinea ( Harvey 1998). Shared characters are: 1) cx-1 medially not fused with the gnathosoma; 2) gnathosoma bearing a long posterior process; 3) presence of a fine curved seta at the anterior margin of I-L-5; and 4) suture line cx-3/4 not extending abruptly anteriorly near the glandulare of cx-4 (see Cook 1974, 1986; Harvey 1998). All known Australiobates species differ from Moramangabates n. gen. in having a distinct suture line extending from the base of the caudal apodeme on cx-4 to the glandular opening on this sclerite, the plesiomorphic number of three pairs of acetabula, and the ventral surface of P-3 straight, not thickened into a central hump. The presence of two strong ventrodistal setae at I-L- 5 in Australiobates is probably a plesiomorphic condition found only in the species of the nominate subgenus; the fine whip-like seta on this segment could be interpreted as a synapomorphy of a group of “ Atractides -like” hygrobatid mite genera ( Gerecke 2003). At present, this is the only water mite taxon above species level endemic to Madagascar. For a discussion of its zoogeographical significance, a study of the male sex is highly desirable: in the family Hygrobatidae , males often display sexual characters of particular importance for the understanding of sister group relationships ( Cook 1974).