J. Moll. Stud. (1992), 58, 13-20
© The Malacological Society of London 1992
research-article |
THE REPRODUCTIVE PATTERNS OF THE FIVE FIJIAN SPECIES OF SEPTARIA (PROSOBRANCHIA: NERITIDAE)
School of Pure and Applied Sciences, University of the South Pacific P.O. Box 1168, Suva, Fiji
The reproductive systems of the five Fijian species of Septaria (S. lineata, S. macrocephala, S. porcellana, S. sanguisuga, and S. suffreni) are described. It was found that the original description of the shell of S. suffreni by Récluz (1841) applied only to male specimens. The septum of females lacked a tongue-like projection and as a result female S. suffreni have in the past been mistaken for specimens of S. macrocephala and S. porcellana. A spermatophore sac with spermatophores was present in female S. lineata, S. sanguisuga and S. suffreni, but was absent in female S. macrocephala and S. porcellana. The spermatophores produced by the three species differed in shape, size and in the number present in the spermatophore sac. The penis of S. lineata, S. sanguisuga and S. suffreni was long and fleshy for manipulating spermatophores, while those of S. macrocephala and S. porcellana consisted of a flap of folded tissue adapted for direct transfer of sperm into the vaginal opening. Male and female individuals of all sizes were present in S. lineata, S. sanguisuga and S. suffreni populations. Both male and female young were present in S. porcellana populations but individuals over 18 mm long were all female. In S. macrocephala populations, young less than 13 mm were all male, while all specimens longer than 15 mm were female, suggesting that this species is protandrous.
(Received 4 December 1990; accepted 7 May 1991)