Integration of DNA barcoding and morphology in ichthyoplankton assessment
Accurate identification of fish eggs and larvae to the species level can be difficult and time-consuming when relying solely on morphological diagnosis or comparative taxonomy (Wibowo et al. 2017). That is why, through DNA barcoding, morphologically similar fish eggs and larvae can be effectively isolated and delineated (Ko et al. 2013). This study demonstrated the convenience and power of establishing COI DNA-based identification method for fish eggs and larvae. In agreement with the morphological diagnosis, the barcoding presented recognizable genetic separation, supporting the identification of 30 ichthyoplankton species in the ECS-CZA. The intraspecific and interspecific K-2-P distances in our analysis met the proposed criteria of DNA barcoding, similar to those established in earlier COI barcoding works (Hebert et al. 2003; Ward et al. 2005; Valdez-Moreno et al. 2010).
When all taxonomic levels are used, DNA barcoding is more sensitive and accurate in ichthyoplankton assessment than MI because it does not depend on the specimen’s appearance or physical quality regardless of life stage (Ko et al. 2013). Therefore, specimens that have been damaged, lack crucial diagnostic traits, or are in developmental phases and unable to be identified using morphology can be identified using barcoding (Ko et al. 2013). Hence DNA barcoding should be used for specimens that have some damage; in contrast, for specimens that are intact, an integrated strategy of MI by an expert ichthyologist and DNA barcoding should be favorable choice of identification. There is a necessity to incorporate these two methods to have a broader view, resolve ambiguities, and improve the accuracy of species identification in particular in ichthyoplankton assessment.