The subgenus Cytostethum Domrow (Acardi : Atopomelidae) : Multiple speciation on the marsupial Potorous tridactylus (Kerr)

Abstract

New locality records are given for the eight species of fur mites of the genus Cytostethum Domrow, subgenus Cytostethum, known to parasitize the potoroo, P. tridactylus. The true host of the ninth, and only other, known species is uncertain. Thirteen new species of Cytostethum S.S. are described from the potoroo: C. potorous, C. mediostriatum, C. procharactum, C. mesocharacturn, C, tubiferum, C. pseudotubiferum, C. neotubiferum, C. tooloomense (female unknown), C. harnatum, C. gracile, C. dendriticum, C, postscutatum and C. spinulatum. A key to all 21 known females of Cytostethum S.S. is given. Such extreme speciation in a group whose members all parasitize the same host is rare, and may result from microisolation caused by variations in fur texture, skin secretions, etc. Not enough populations have been analysed to determine the influence, if any of geographical isolation on speciation in these mites, but several are known to be widespread both on the mainland of south-east Australia and in Tasmania, supporting the thesis that potoroos in these two areas are conspecific.