THE LIFE HISTORY AND BIOLOGY OF A MARINE HARPACTICOID COPEPOD, TISBE FURCATA (BAIRD)

Abstract

During its life cycle T. furcata passes through 6 naupliar and 6 copepodid stages, all of which are benthonic. These stages, descr. and figured, present the usual development common to most harpacticoids studied. Developmental series from culture expt. were obtained in 4 separate years. 30 or more broods were studied, some for 2 generations. The avg. no. of eggs per brood was 42.9. There was an incubation period of 2.5 days, and the success of incubation and development to maturity was 80%. The naupliar period lasted about 5 days. Sexual maturity was reached in 10 to 25 days. The sex ratio was about one female to 2 males. Isolated females produce 7 to 12 broods at intervals of about 3 days, and one mating sufficed for fertilization of all the eggs produced. There was no evidence of parthenogenesis. The min. time between generations was 15 days, but usually 19 to 24 days. The longest life span observed was 71 days.