Effects of photoperiod, temperature and salinity on hatchery-reared larvae of the greenback flounder ( Rhombosolea tapirina Günther, 1862)

The greenback flounder ( Rhombosolea tapirina) is considered to have potential as an aquaculture species in southern Australia. Experiments were conducted to determine the optimal photoperiod, temperature and salinity for rearing of larvae through metamorphosis. Experiments were carried out in 31 tanks in a recirculating system. Optimal photoperiods were found to be 18–24h light, which increased the growth rate but had no effect on survival. Total darkness resulted in 100% mortality by Day 20 post-hatch. The optimal temperature for larval rearing was not clearly identified, but 19–20 °C gave better growth than lower temperatures. There were no clear temperature effects on survival trends over the range used, although 16 °C resulted in significantly lower survival than 17 or 19 °C. A salinity of 15‰ resulted in lower survival, compared with either 25 or 35‰, but there were no salinity effects on growth over the tested range.