FOOD OF THE BLIND CAVE FISHES OF NORTHWESTERN AUSTRALIA

WA Museum Records and Supplements | Updated 1 decade ago

Abstract - Cape Range peninsula, in the arid northwest of Western Australia, contains the only cavernicolous fishes in Australasia, both of which are considered as vulnerable or endangered. They are associated with a stygofauna considered to be of Tethyan origin. Ophistenon candidum (Mees, 1962) (Synbranchiformes: Synbranchidae) and Milyeringa veritas Whitley, 1945 (Perciformes: Eleotrididae) occur widely in underground waters and are endemic to the peninsula. The gut contents of existing collections were examined to elucidate their prey. Both species of troglobitic fish are opportunistic in their feeding, able to utilize occasional packets of energy entering the stygal realm.

Ophistemon candidum eats the specialised stygofauna of the region, including Halosbaena tulki (Poore and Humphreys, 1992) (Thermosbaenacea) and atyid shrimps (Stygiocaris spp.) and also feeds opportunistically on aquatic larvae living in the more open part of the subterranean system. The biogeographic affinities of O. candidum is in accord with that of its main prey. The gut contents constitute the only records of Stygiocaris and Halosbaena from Tantabiddy Well (C-26), the type locality of O. candidum. M. veritas primarily feeds opportunistically on invertebrates accidentally introduced into the aquatic system (mostly terrestrial isopods and cockroaches) but also feeds on the stygofauna.