Effects of temperature, salinity, diet and stocking density on development of the veined Rapa whelk, Rapana venosa (Valenciennes, 1846) larvae.

The veined rapa whelk Rapana venosa (Valenciennes, 1846) is an important and valuable fishery resource but has not been cultured on a large scale. We studied the effects of environmental factors, temperature, salinity, diet, and stocking density, on growth and survival of larvae to determine optimal artificial culture conditions. The optimal temperature was 25-31 °C at 30 ppt at densities of about 200 veligers per liter, under which the mean shell length (737-1006 μm) and survival rate (36-45%) were higher than those held at other temperatures. When cultured under a salinity of 25 ppt at 25 °C with densities of about 200 veligers per liter, larvae had the highest mean shell length (878.45-917.88 μm) and survival rate (29.75%). Larvae were fed a mixed diet, Pseudoisochrysis paradoxa + Tetraselmis chui + Chlorella vulgaris. Optimal stocking density was 300 veligers per liter for the first 5 days and was 100 veligers per liter afterward at 25 °C and 30 ppt. [ABSTRACT FROM AUTHOR]