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

Analysis of otolith 87Sr/86Sr to elucidate salinity histories of Nurseryfish Kurtus gulliveri (Perciformes:Kurtidae) in a tropical lowland river in northern Australia

“…Males with egg masses and newly hatched larvae have been collected in freshwater reaches , whereas juveniles and adults have been recorded from fresh water to saline estuarine habitats (Berra et al 2007, Pusey and Kennard, unpublished data, DAC, unpublished data). Extensive research has been done on Nurseryfish reproductive biology and early life history (Berra and Neira 2003, Berra and Aday 2004), anatomy and histology (Berra and Wedd 2001, Berra and Humphrey 2002, Carpenter et al 2004, genetics (Ezaz et al 2007, Sommer et al 2011, disease (Humphrey and Berra 2006), age and growth (Berra and Aday 2004), and diet (Berra and Wedd 2001), but almost nothing is known of the species' movements. We addressed this knowledge gap by analyzing 87 Sr/ 86 Sr in the otoliths of Nurseryfish from a tropical river/estuary system in northern Australia to examine their movements and assess the potential significance of movement by Nurseryfish as a mechanism for transporting energy and nutrients across salinity gradients.…”

Swim bladder and posterior lateral line nerve of the nurseryfish, Kurtus gulliveri (Perciformes: Kurtidae)

“…The coastal riverine habitats of the nurseryfish are typically very turbid and heavily populated with piscivorous crocodiles, sharks, sawfish, and barramundi (Berra and Wedd, 2001). Nurseryfish feed mostly on small mobile prey such as crustaceans and small fish.…”

“…Swimming through sinusoidal body movement would be expected to cause varying tension along the nerve. However, observations of swimming behavior of nurseryfish in an aquarium indicate that they normally remain motionless and typically use sinusoidal body swimming after prey items are detected (Berra and Wedd, 2001). Videotape of Kurtus gulliveri swimming in a 5,000-liter aquarium at the Territory Wildlife Park outside of Darwin shows that nurseryfish spend most of their time hovering placidly in mid-water.…”

“…Berra and Humphrey (2002) speculated that the highly vascularized dermis engorges with blood and helps clamp the egg mass in place. Eggs and pre-and postflexion larvae were described by Berra and Neira (2003) who noted a prominent, inflated swim bladder in post-yolk-sac young. The larvae are pelagic and hatch at about 5 mm body length.…”

“…A map and description of the study area are given by Berra (2003). Berra and Wedd (2001) described the prawn, isopod, and fish diet of nurseryfish. The gross anatomy and histology of the male's hook and skin were examined by Berra and Humphrey (2002).…”