Analyses of microscopic ossicles and mitochondrial genome of holothuria (mertensiothuria) leucospilota from Sedili Kechil, Johor, Malaysia

• Main Author: Badrulhisham, Nur Sabrina
• Format: Thesis
• Language: English; English; English
• Published: 2023
• Subjects: QR Microbiology
• Online Access: http://eprints.uthm.edu.my/10989/

The white threads fish Holothuria (Mertensiothuria) leucospilota (Brandt, 1835) or locally known as bat puntil is a widely distributed sea cucumber species in Malaysia. The species is categorised as low commercial value species, but it will be sought after if high-value species at fishing zones are depleted. Despite issues of sea cucumber taxonomic identification, the species has no representative of genetic documentation of mitogenome from Malaysia. In this study, the mitogenome of H. leucospilota collected from Malaysia, specifically from Sedili Kechil, Kota Tinggi, Johor was sequenced and annotated using Illumina Novaseq6000 next-generation sequencing (NGS) technology. A sufficient quantity and acceptable quality of DNA extract from H. leucospilota was necessary to ease the process of NGS. The calcareous ossicle shape and external morphological characteristics of H. leucospilota from Sedili Kechil were also recorded to assist early identification and provide an update of morphological characters of H. leucospilota from Sedili Kechil. The current findings showed that there were five ossicle shapes: button-shaped, rod-shaped, perforated plate, table, and anchor-shaped ossicles found in different body parts of H. leucospilota. Then, a sufficient amount of DNA extract was obtained due to an additional step and modification of centrifugation speed process during DNA filtration of column based FavorPrep DNA extraction kit. The PCGs phylogenetic analyses show that H. leucospilota is in order Holothuriida in a monophyletic group, forming sister group with H. hilla. This study recorded the first mitogenome of H. leucospilota from Malaysia. Along with the species-specific ossicle shape documentation, these findings will provide useful taxonomic and genetic reference of H. leucospilota in Malaysia