DNA Barcoding in Species Identification of Flying Fish (Exocoetidae) and Halfbeaks (Hemiramphidae) Larvae: A Comparative Study of the Database Over a Decade

Abstract

The families Exocoetidae and Hemiramphidae comprise migratory species, whose identification based on their external morphological characteristics can be challenging because of their similarities. DNA barcoding has been used in taxonomic and evolutionary studies to address these issues. The morphological characteristics of fish larvae change rapidly and often lack distinctive features, posing a challenge for species-level identification. This study used DNA barcoding to identify flying fish and half-beaked larvae. Using plankton nets, sampling was conducted seasonally between 2010 and 2013 in Nanwan, Taiwan. A total of 903 individuals were collected, of which 111 were identified as flying and half-beaked fish based primarily on morphological characteristics. The individuals were further classified into 18 distinct morphotypes. DNA barcoding was performed between 2011 and 2013 using the Taiwan Fish and Barcode of Life Data Systems (BOLD) database. Among the 18 morphotypes, 13 were identified at the species level, 3 at the genus level, and 2 at the family level. After a decade, we utilized a database and phylogenetic tree for reanalysis, enabling species-level identification. The species identification rate increased from 61.11 % to 100 %. Therefore, a robust database can improve species identification accuracy. DNA barcoding allows accurate identification of larval fish at the species level. The morphological characteristics of larval fish confirmed using DNA can be used for future morphological classification and research on their early life histories, including their spawning grounds, spawning seasons, and migratory distributions. This is crucial for resource management and sustainable utilization of flying fish fisheries.