Effects of temperature on growth of the Japanese spiny lobster, Panulirus japonicus (V. Siebold) phyllosomas under laboratory conditions

Abstract

The effects of temperature on growth of phyllosomas of the Japanese spiny lobster Panulirus japonicus were investigated. Phyllosomas were individually reared at four temperatures (20°, 22°, 24° and 26°C), and intermoult period and moult increment were monitored. The improved Bêlehrádek’s equation, G = aL^b (T–α)^c(β–T)^d, was used to describe the relationship between growth characters (G: intermoult period, moult increment or daily growth increment), body length (L) and temperature (T), with a and b being constants that change at 17·8 mm body length, c and d being common constants for all sizes, and α and β being the conceptual biological lower and upper critical temperatures, which are variables with body length. The intermoult period increased and the moult increment decreased with decreasing temperature. However, a negative influence on both the intermoult period and the moult increment was observed at 26°C for medium-sized and large phyllosomas. The largest daily growth increment was obtained at 26°C up to 15·0 mm body length, and then at 24°C. This indicates that the optimum temperature for growth decreases from 26° to 24°C at 15·0 mm body length. This optimum temperature for growth seemed to be optimal for survival.