Introduction
The humphead wrasse, also known as the Napoleon wrasse (Cheilinus undulatus), is a highly valuable marine fish species predominantly found in coral reef habitats across the Indo-Pacific region. Unfortunately, it is listed as Endangered on the International Union for Conservation of Nature (IUCN) Red List due to severe population declines caused by overfishing, particularly for the aquarium trade and the live reef fish food market (Sadovy & Vincent, 2002). Their slow growth rate and late sexual maturity make them highly susceptible to overexploitation, further exacerbating population declines. Given these challenges, conservation efforts are critical, including the establishment of marine protected areas (MPAs) and the implementation of sustainable fishing practices to ensure the species’ long-term survival. Despite its high commercial value, aquaculture efforts for humphead wrasse remain rare, largely due to the difficulty in breeding and rearing the species in captivity. T o date, only extremely rare instances of successful hatchery production of humphead wrasse seed have been documented. At the Borneo Marine Research Institute (BMRI), Universiti Malaysia Sabah (UMS), initiatives to domesticate the species began several years ago, yielding promising results in broodstock nurturing. The challenges of breeding this species stem from its complex reproductive behaviors , specific dietary requirements, and prolonged larval phase, all of which hinder large-scale aquaculture production. Additionally, its slow maturation rate presents further obstacles in achieving a sustainable breeding cycle. To advance aquaculture efforts, it is essential to establish a comprehensive baseline of biological and ecological information on this little-known species. This paper presents the ongoing strategies and early findings of humphead wrasse domestication, offering insights that could contribute to future aquaculture development and conservation management.
Materials and Methods
A total of 65 tails of C. undulatus broodstocks reared in the captivity throughout six months of research period and fed daily with fresh squid (Sepia sp. ) in a 150 ton tank at the Fish hatchery of Borneo Marine Research Institute, Universiti Malaysia Sabah, Kota Kinabalu, Sabah, Malaysia . Sex determination was carried out based on morphological assessment including the presence of eyeline, hump on head and genital papillae, of the C. undulatus were carried out to identify the sex (Tan et al., 2019). Another cohort of fish (30 fish ; 700-1200g) were subjected to morphometric and meristic characterization, as well as nutritional profile (proximate analysis, amino acids, fatty acids, vitamins and minerals) using standards methods. In the weaning experiment fish were placed in a 30 ton round tank with different feeding regimes .
Results and Discussion
Our preliminary findings show that C. undulatus exhibited an isometric growth pattern with more than half of the population being under the unknown status (neither male or female) . Morphologically, females were distinguished by a less pronounced hump on the head and a visible eyeline behind the eyes, which was absent in males. Additionally, the study clearly revealed that male C. undulatus displayed an elongated genital papilla, whereas females had a rounded genital papilla with a distinct small egg hole. Induced spawning trials using hormone treatments have been conducted, with Ovaplant demonstrating the highest potential. Only ovaries were obtained from this fish cohort. On the other hand, n utritional analysis of C. undulatus has been done to provide valuable insights into the nutritional profile of the fish, which can be used to develop species-specific feeds. Significant differences were observed between the dorsal and ventral fillets of humphead wrasse, highlighting distinct nutritional strengths. The dorsal portion was higher in protein, essential amino acids, and minerals such as calcium and magnesium, making it ideal for consumers seeking muscle-building nutrients and bone health support. In contrast, the ventral portion contained higher fat content, particularly omega-3 fatty acids like DHA, as well as vitamin D, offering benefits for cardiovascular health, immune function, and energy. By-products from the fish also reveal a high potential nutritional profiling with high protein and mineral contents. Meanwhile, w eaning from trash fish to formulated feed took at least about 2 month with a fasting-strategy. Survival rate during weaning period remains high with a flow-through culture system in round fiberglass tanks. An on-going feeding trial is conducted to evaluate the growth performance of humphead wrasse fed formulated feeds in captivity .
References
Tan, B. L., Ching, F. F., & Senoo , S. 2019. Body size and morphological characteristics in sex determination of humphead wrasse Cheilinus undulatus in captivity. J. Phys.: Conf. Ser. 1358 012010.
Sadovy, Y.J., & Vincent, A.C.J. 2002. Ecological issues and the trades in live reef fishes. In: Sale, P.P. (ed.), Coral Reef Fishes Dynamics and Diversity in a Complex Ecosystem. Academic Press, San Diego, pp. 391–420.