Laboratory observations on the reproductive and molt cycles of the robinson crusoe island lobster Jasus frontalis (milne-edwards, 1836)

摘要

Observations on molting, mating, embryo- carrying, hatching, and early larval development were made on the Juan Fernandez lobster Jasus frontalis maintained in seawater aquaria at the Coastal Aquaculture Center of the Universidad Catolica del Norte, Coquimbo, Chile. Males underwent their annual preproduction molt from February through March at temperatures around 17 deg C and females molted from mid-April to mid-June at temperatures of 13 to 15 deg C. Growth at each molt was about 1.3 to 3.1 mm in both males and females, and hardening of the carapace occurred over 3 dyas. Embryo- carrying was initiated between the months of June and August, with hatching of larvae between October and December. Embryonic development lasted 115 days at 13 deg C and 76 days at 18 deg C. Hatching released a naupliosome larvae normally occurring between sunset and before midnight. The naupliosoma swam actively for 10-20 min, then molted to produce the first phyllosome larvae. Five days after hatching, 2-8% of the egg mass remained attached to the pleopods of the females, as did numerous empty capsules. These remaining eggs were in the fist stage of development. Six stages of larval development were obtained. The six larval stage were observed after 56 to 92 days, depending upon incubation temperature. At 14-15 deg C the fifth stage was obtained at 77 days; at 17-18 deg C the sixth stage was obtained at 79 dyas, and after 56 days at 20 -21 deg C.