Species identification and morphology of fish eggs from Jiangmen coastal waters in spring using DNA barcoding

Jiangmen is located in the southwest of the Pearl River Estuary. It is the spawning ground and nursery ground for various small fish. We identified the species of fish eggs from Jiangmen coastal waters of the Pearl River Estuary in sping based on DNA barcoding analysis, then described and preliminarily classified the morphological characteristics of fish eggs. We acquired a total of 13 taxa, which belonged to three orders and ten families. Four and eight taxa were identified to species and genus levels, respectively (Ambassis gymnocephalus, Gerres limbatus, Sillago sihama, Cynoglossus puncticeps, Sardinella sp., Stolephorus sp., Acanthopagrus sp., Alepes sp., Johnius sp., Sillago sp. and Cynoglossus sp.). One taxon was identified in family (Leiognathidae sp.). The results demonstrate that most fish eggs collected in the survey area can be classified by morphological characteristics such as shape, fish eggs size, perivitelline space, number and pigment distribution of oil globules. In addition, the colour, amount and distribution of pigments of the embryo are also important in species identification when the embryo is well developed. However, it is difficult to distinguish the closely related species only by the morphological characteristics of a single developmental stage. Further morphological studies should be conducted in the future.