The valuable sea cucumber Holothuria scabra, known as ‘sandfish’, has potential for restocking. However, there is little information available to determine the size of the no-take zones (NTZs) needed to protect the released animals so that they can form nucleus breeding populations. To do this, we measured short-term movement paths of released juvenile (1–105 g) and wild adult (130–690 g) sandfish in a seagrass bed in New Caledonia.
Population genetics analyses should be considered when releasing hatchery-produced juveniles of the sea cucumber Holothuria scabra when spawners from nonlocal populations are used. In New Caledonia, within-region genetic heterogeneity of H. scabra populations (examined through allozyme electrophoresis of 258 animals) indicated high gene flow between nine sites and F<sub>ST</sub> values dOld_ID not deviate significantly from zero.
Sea cucumber diseases that arise in the hatchery can cripple production and undermine restocking programmes. A rapid protocol for the external examination of juvenile sea cucumbers was developed in order to screen for disease and poor health.
Sandfish is arguably the most commercially valuable of the tropical species of sea cucumber that are processed into bêche-de-mer. It is widely distributed throughout the Indo-Pacific, occurring in shallow inshore areas where it is easily accessible to coastal fishers. A-grade bêche-de-mer processed from sandfish commands some of the highest prices on the international market. But these same attributes also make it vulnerable to overexploitation. Sadly, this has happened in most places where it occurs.
Two commercially valuable holothurians, the sandfish and golden sandfish, vary in colour and have a confused taxonomy, lending uncertainty to species identifications. A recent molecular study showed that the putative variety Holothuria (Metriatyla) scabra var. versicolor Conand, 1986 (‘golden sandfish’) is a distinct species from, but could hybridize with, H. (Metriatyla) scabra Jaeger, 1833 (’sandfish’). Examination of the skeletal elements and external morphology of these species corroborates these findings. The identity of H.
The specific aims of our study were: (1) to determine whether cultured juvenile H. scabra released near mangrove–seagrass and coral reef flat habitats suffered different levels of predation, and (2) to identify the predators of juvenile H. scabra and determine whether cages provided short-term protection for released individuals.
Juvenile cultured sandfish (Holothuria scabra) with a mean size of 35.6 F11.4 S.D. were released on soft substrata near mangrove–seagrass and lagoonal coral reef flat habitats in the Western Province of Solomon Islands. Mean survival of H. scabra at the mangrove–seagrass sites was 95–100% 1 h after release and approximated 70% 3 days later. At the coral reef flat sites, however, mean survival was as low as 37.5% 1 h after release and total mortality occurred in two of the three releases within 48 h. Mortality of the juvenile H.
The Coastal Aquaculture Centre (CAC) of the International Center for Living Aquatic Resources Management (ICLARM) in Solomon Islands has started to assess the potential of enhancing populations of sea cucumbers associated with coral reefs (Anon, 1993). The first step in this process is to determine whether it is possible to produce juvenile sea cucumbers en masse at low cost. To this end, the CAC is holding broodstock of a variety of species for experiments on induction of spawning and larval rearing.
Twenty species of sea cucumbers from India are described briefly, with photographs which will enable research workers and farmers to identify them.
Sea cucumber fisheries in Malaysia are exploited off the coastal waters around the coral reef regions in Sabah in East Malaysia. In Peninsular Malaysia, this resource is minimally exploited because more than 90 % of the coral reef islands in both the east and west coasts have been gazetted as marine parks or as fisheries prohibited areas, where fishing activities are prohibited in the vicinity.