Effect of Temperature on Ovarian Maturation Stages and Embryonic Development of Mud Spiny Lobster, Panulirus polyphagus

摘要

A study was carried out to determine the ovarian maturation stages of 100 days and the effect on the embryonic development of mud spiny lobster, Panulirus polyphagus. For the ovarian development, treatments are involving water temperature (low temperature at 15-20°C and high temperature at 30-35°C) and control group at ambient condition of temperature at 26-29°C. Results showed that there were no significant difference (p>0.05) in all treatments in terms gonadosomatic index (GSI) and oocyte stageindex (OSI), however, there were significant difference (p<0.05) at oocyte diameters for all treatments. While, for the embryonic development, five berried females kept at temperature 25-28°C (control), 20°C (low temperature) and 30°C (high temperature). In control, the largest mean diameters were 0.668±0.037 mm (Day 11). However, in low temperature (R1 and R2), the largest mean diameters were 0.632±0.039 mm (Day 5) and 0.598±0.041 mm (Day 17) and in high temperature (R1 and R2), the largest meandiameter were 0.651±0.012 mm (Day 4) and 0.679±0.022 mm (Day 3). Therefore, ambient condition was found to be suitable to stimulate ovarian development as P. polyphagus could definitely adapt to the natural environment compared to extreme conditions and culturing the berried female in low temperature could cause mortality to the lobster and trigger the berried female to release the eggs unhatch due to stress.