Unionicola (Dimockatax) ernstingi n. sp. (Acari: Unionicolidae) from freshwater mussels, Anodontoides radiatus (Conrad, 1834) in Louisiana, USA

Abstract

Unionicola (Dimockatax) ernstingi n. sp. (Acari: Hydrachnidia: Unionicolidae) is described from freshwater mussels, Anodontoides radiatus (Conrad, 1834), from Twelve Mile Creek, St. Helena Parish, Louisiana, USA. The suspected sibling species, U. tumida (Wolcott, 1898), occurred in the same locality in another mussel species, Strophitus subvexus (Conrad, 1834). Unionicola ernstingi is distinguished from other North American members of the subgenus by the number of clawlets on the tarsus of the pedipalps. It closely resembles U. tumidoides (Vidrine, 1986) from Asia, but it is distinctive in body size and chaetotaxy of the first walking legs. The pedipalp morphology, body size, and chaetotaxy of the first walking legs are used to separate the five currently known species in the subgenus Dimockatax Vidrine, 1992.