Reproductive Biology of the Sea Snake, Laticauda semifasciata, in Taiwan

Four species of sea snakes, Laticauda semifasciata, L. laticaudata, L. colubrina and Emydo- cephalus ijimae occur near Orchid Island on the southeastern coast of Taiwan. We describe here aspects of the reproductive biology of the most abundant species, L. semifasciata, based on a sample of 243 snakes collected between April 1986 and March 1987. Eight meristic and morphometric characters were examined for sexual dimorphism. The two best indicators were caudal width and the number of subcaudal scales. Minimum snout-vent lengths at sexual maturity for male and female snakes were 70 and 80 cm, respectively. The breeding season for female snakes was prolonged and peaked between August and November. There was no seasonal fluctuation in the weight or dimensions of the testes; sperm were found within the vas deferens throughout the year. Mating took place sometime before ovulation. Three to seven eggs (mean, 4) comprise the clutch. There are indications that some females may breed more than once per year. Eggs were laid in muddy water within tidal caves where they would not be inundated by sea water; moisture levels during incubation were maintained by fresh water dripping from condensation on the cave roof. The incubation period was 4 to 5 months.