KMITL

Permanent URI for this communityhttps://dspace.kmitl.ac.th/handle/123456789/1

Browse

Settings

Author: search.filters.author.Krajangdara, TassaponSubject: search.filters.subject.COI

Search Results

Now showing 1 - 2 of 2
  • Loading...
    Thumbnail Image
    Some of the metrics are blocked by your 
    consent settings
    Item type:Publication,
    Resolving Species Identification and Distribution Patterns of Neotrygon spp. in Thai Waters: Inefficiency of Morphometric Analysis and the Power of COI Gene Barcoding and Phylogenetics
    (2025-01-01)
    Panithanarak, Thadsin
    ;
    Karuwanjaroen, Ratima
    ;
    Utama, Chanapa
    ;
    Laongmanee, Penchan
    ;
    Meejan, Titirat
    Three species of maskrays in the genus Neotrygon have previously been reported in Thai waters. However, the high morphological similarity among species within the blue-spotted maskray complex (Neotrygon spp.) makes accurate identification challenging. This study aimed to confirm species identification in Neotrygon spp. using morphometric and genetic data and to further examine their phylogenetic relationships in Thai waters by analyzing mitochondrial COI (cytochrome c oxidase subunit I) sequences. Multivariate analysis (PCA) of 37 morphometric characters from 55 specimens proved insufficient for species-level discrimination. However, molecular phylogenetic analysis of 14 unique COI sequences from Thai waters, combined with 61 reference sequences from previously documented related species and closely related species, identified two monophyletic clades. These clades corresponded to two species: N. varidens, found exclusively in the Gulf of Thailand, and N. malaccensis, recorded for the first time in Thailand, occurring in both the Gulf of Thailand and the Andaman Sea. This DNA-based identification provides clear evidence for species boundaries within Thai Neotrygon species and highlights the importance of molecular tools for distinguishing morphologically similar marine species in the Indo-Pacific region.
  • Loading...
    Thumbnail Image
    Some of the metrics are blocked by your 
    consent settings
    Item type:Publication,
    DNA-based species identification of shark fins traded in thai markets
    (2023-08-01)
    Klangnurak, Wanlada
    ;
    Arunrugstichai, Sirachai
    ;
    Manopawitr, Petch
    ;
    Krajangdara, Tassapon
    Shark fins are among the most highly prized seafood products in the world with massive consumption in Asia over the past several decades. The demand for shark fins is a major driver of the enormous population declines of elasmobranchs that are generally vulnerable to overexploitation. This study aims to better understand the species composition of shark fin products in Thailand and their conservation statuses by using DNA-based species identification. Various types and sizes of shark fins were collected from 4 locations in Thailand. DNA barcoding method based on a fragment of the cytochrome c oxidase subunit I (COI) gene was applied to species identification. Fins from at least 15 shark species were found from Thailand’s markets. The spottail shark (Carcharhinus sorrah) and the night shark (Carcharhinus signatus) were the two dominant species presented in this study. 34% of identifiable samples are the species that have not been record in this region. 62% of species detected from the fin samples are categorized under the threatened categories of IUCN Red List. Species composition reported in shark fin products potentially helps indicate the appropriate conservation action and increases awareness from monitoring the trade in elasmobranch products.