THE SUBTERRANEAN AQUATIC FAUNA OF THE NORTH WEST CAPE PENINSULA, WESTERN AUSTRALIA.

WA Museum Records and Supplements | Updated 1 decade ago

Abstract: The current stalus of the subterranean aquatic fauna on the semi-arid tropical North West Cape peninsula of Western Australia is discussed and placed in the context of the rich troglobitic fauna of Cape Range. The range of all four subterranean species has been considerably extended and an amphipod added to the known fauna. The fauna includes the only vertebrate troglobites known from Australia.

The Blind Cave Eel. Ophis/ernon candidum. has been seen for the first time in more than a decade and from the east coast of the peninsula where it was previously unkown. Allozyme electrophoretic data show that the Blind Gudgeon. Milyeringa veritas, is not panmictic within its known range. The overt geological discontinuities along the coast of the North West Cape peninsula do not constitute genetic barriers between the gudgeon populations.

Allozyme electrophoretic data confirm that two species of at yid shrimps occur but the species were found on opposite sides of the peninsula. Analysis suggests that the species composition on the east coast is different from that on the west coast.

The relationship between genetic and metric distance between the populations suggests that the coastal fauna is essentially linear along the coast and does not spread beneath Cape Range. Within Cape Range all four wells with water contain an undescribed amphipod. Allozyme electrophoretic data suggest the presence of a single species showing genetic discontinuities through its range.

There is a cline in the water chemistry, with most parameters increasing from the mid-east coast, round the north coast and south along the west coast of the peninsula. All coastal species seem to occupy the full range of water chemistries sampled. There is a lack of effective monitoring of the quantity and quality of the water. Examination of diverse evidence from a number of sources suggests that the water table is declining and becoming more saline. Potential disruption of the habitat is discussed and a model presented which indicates that the critical areas for conservation may be close to the scarp where. owing to the absence of wells, the fauna has not been sampled.