ASFB Home > The effects of spatial and temporal factors on the abundance of seven key finfish species along south-western Australia.

Early Life History of the Nurseryfish, Kurtus Gulliveri (Perciformes: Kurtidae), from Northern Australia

Francisco Neira and Francisco J Neira

Australian Maritime College, BEACONSFIELD, AUSTRALIA

THEME: ASFB

Eggs and larvae of nurseryfish, Kurtus gulliveri, one of the two know species of the Kurtidae, are described and illustrated for the first time using material collected in two rivers of Australia's Northern Territory. Nurseryfish are unique in that males carry a cluster of fertilised eggs on a bony hook projecting from their foreheads. No brooding males were captured during this study, although one partial egg cluster was found adjacent to a male caught in a gill net. Three clusters found attached to gill nets without associated males had ca. 900-1300, slightly ellopitcal, 2.1-2.5 mm diameter eggs, each with multiple oil droplets and a single, relatively thick chorionic filamentous strand at opposite poles. Larvae are pelagic, and hatch at ca. 5 mm body length (BL) at the flexion stage possessing a large yolk sac, forming dorsal, caudal and anal fins, and little pigment. Notochord flexion and yolk-sac resorption are complete by 6.8 mm BL. Post yolk-sac larvae resemble adults in having a hatchet-shaped body that is almost transparent in live fish, including a large head with relatively small eyes, preopercular spines and a prominent, inflated gas bladder. Larval length data obtained fortnightly in August-November 2001 suggests that breeding occurs during Northern Australia's dry season (May-November), and that larvae leave the pelagic environment at about 25 mm BL.