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.