Scopus

Due to the issues of species substitution and product mislabelling of beche-de-mer worldwide, this study aimed to identify the species of seven gamat-based beche-de-mer specimens from Kuah, Langkawi Island, Kedah, Malaysia based on ossicle shapes and non-protein-coding 12S mitochondrial rRNA gene sequences. In general, ossicles were well extracted from the specimens. At least eight ossicle shapes were observed i.e. large I-shaped rod, perforated plate, table, C-shaped rod, button, rosette, I-shaped rod and X-shaped rod. Except for button, I-shaped rod and X-shaped rod, the other five ossicle shapes are common in Stichopus horrens. However, the species status could not be resolved at this level due to the presence of uncommon ossicle shapes and the physical features of the specimens could not be used as supporting data as they were different from the live or unprocessed sea cucumber. In this study, 12S mitochondrial rRNA gene sequences were analysed using the Basic Local Alignment Search Tool programme for Nucleotides (blastn), resulting in the species identification of the beche-de-mer specimens as S. horrens, known locally as gamat emas (golden sea cucumber) with 96-99% similarity (an average of 98%). The phylogenetic trees based on the Neighbour-Joining method, Maximum Parsimony method and Maximum Likelihood method indicated that all 12S mitochondrial rRNA gene sequences of the beche-de-mer specimens clustered with the reference samples of S. horrens from Pangkor Laut, Pangkor Island, Perak, Malaysia, supporting the BLASTN results and confirming their species status as S. horrens. Furthermore, 10 partial 12S mitochondrial rRNA gene sequences of the reference samples and the beche-de-mer specimens of S. horrens were registered with the GenBank (Accession No.: KX879628-KX879637). Overall, the findings suggested that the species identification of the beche-de-mer specimens using 12S mitochondrial rRNA gene sequence gave better inference than ossicle-shape identification. The outcomes of this study benefit enforcement agencies in their work of monitoring and overcoming the issues of species substitution and product mislabelling of beche-de-mer or commercial dried sea cucumber in Malaysian markets as well as in global markets. � Universiti Putra Malaysia Press.

The abundance of sea cucumbers (Phylum Echinodermata: Class Holothuroidea) in Malaysian waters has been gradually declining in past decades. Due to the lack of recent studies on the status of sea cucumber populations in Kudat, Sabah, Malaysia, this study was conducted. This study aimed to identify the species of a timun laut morphospecies i.e. Holothuria (Metriatyla) scabra and two gamat morphospecies i.e. Stichopus horrens and Stichopus ocellatus that were collected from Limau Limawan based on ossicle shapes and non-protein-coding 12S mitochondrial rRNA gene sequences. A number of five main ossicle shapes were microscopically identifed without microscopic size measurement i.e. rod, plate, rosette, button and table. However, a number of ossicle shapes for S. horrens and S. ocellatus recorded in the previous studies were not observed in this study and this could be due to the body deformation of the specimens. Interestingly, fve specimens of H. scabra exhibited additional ossicle shapes other than the smooth button and the table. Despite the absence of common ossicles and the presence of additional ossicle shapes, 12S mitochondrial rRNA gene sequences analysed using the Basic Local Alignment Search Tool programme for Nucleotide (blastn) resulted in the species identifcation of the specimens of morphospecies H. scabra and S. horrens as H. scabra and S. horrens; however, the specimen of morphospecies S. ocellatus was identifed only up to the genus level i.e. genus Stichopus, showing the lack of 12S mitochondrial rRNA gene sequences of S. ocellatus in the GenBank until 15 September, 2016. In total, 31 partial sequences of 12S mitochondrial rRNA gene were registered with the GenBank (Accession No.: KX913672-KX913702). The fndings also suggested that species identifcation based on 12S mitochondrial rRNA gene sequence showed better inference than the ossicle shape identifcation. In summary, the three morphospecies were morphologically and genetically verifed as H. scabra, S. horrens and S. ocellatus. Despite the fact that more specimens and more molecular techniques are required to generate better conclusive outcomes, the current fndings give better insight into the importance of morphological and molecular approaches and the present status of the timun laut species and gamat species in Kudat. � Universiti Putra Malaysia Press.