Reproduction of the
commercial sea cucumber Holothuria scabra (Echinodermata: Holothuroidea) in
the Solomon Islands
C. Ramofafia, M. Byrne, C.S. Battaglene-2003
Marine
Biology, 142(2) : 281-288
Abstract:
Over a 3-year period (1996-1998), reproduction of the
commercial sea cucumber Holothuria scabra (Jaeger, 1833) was
investigated in the Solomon Islands to determine the spawning pattern and
whether gametogenesis is continuous or seasonal. The gonad consisted of a
single cohort of tubules that developed uniformly. Macroscopic examination
of the gonads revealed that mature gametes were present throughout the year.
Individuals with gonads at different stages of maturity were present in most
samples. Partly spawned gonads were prevalent in females, whereas mature
gonads were prevalent in males. The time at which the peak gonad index was
recorded differed among years. Although gametogenesis was continuous, with a
potential for prolonged gamete release, a period of enhanced spawning
occurred during the dry season, from September to December. Maximum gonad
indices were reached prior to and during this period of enhanced spawning.
Histology revealed that gametogenesis reinitiated in partly spawned gonads,
resulting in the presence of gametes at different stages of development in
the gonad. The uniform growth of gonad tubules indicated that H. scabra does
not conform to the progressive tubule recruitment model described for
holothurian oogenesis. Continuous reproduction in H. scabra and
prolonged availability of mature gametes would facilitate use of this
species for aquaculture.
(Department of Anatomy and Histology F13, University
of Sydney, NSW 2006, Australia, Phone: +677-25090, Fax: +677-23296, E-mail: chris.ramofafia@ffa.int)