Health assessment of Holothuria scabra (Jaeger, 1938) from pond culture in Thailand: Size distribution and gonadal development

The assessment of sea cucumber health in Thailand is incomplete, as it has not included Holothuria scabra , a potentially valuable species for aquaculture. In this study, we examined the health status and gonadal development of H. scabra in relation to its size distribution using morphological and histological methods, as well as the terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assay. All sea cucumbers were obtained between July and August 2024 from pond cultures on Koh Yao Noi Island, Phang Nga Province, a coastal area on the Andaman Sea in Thailand. The specimens could be divided into three size classes: Group I (3.5–6.8 cm), Group II (16.5–19.5 cm), and Group III (20.5–23.5 cm). Specimens in Group I were sexually undifferentiated, whereas specimens in Groups II and III were predominantly sexually mature. The histological alteration index and average value of alteration showed a slight frequency of histopathological alterations in intestines, but the TUNEL assay strongly indicated the presence of apoptotic cells in the intestines, more evident in Group I specimens than other groups ( p < 0.05).