Abstract: The ecological distribution of ichthyoplankton around Oujiang estuary was surveyed via horizontal trawl in spring and autumn in 2015. 16 species were identified in the two seasons, belonging to 15 genera of 14 families in 8 orders, with most species in Perciformes. 42 individual fish eggs and 295 individual fish larvae and juveniles were collected in the two seasons totally. The species number and abundance of fish eggs, larvae and juveniles in spring were both higher than those in autumn. The dominant species of fish eggs was Konosirus punctatus in spring and Cynoglossus sp. in autumn, and the dominant species of fish larvae and juveniles were Liza haematocheila, Lateolabrax japonicus and Chaeturichthys stigmatias in spring and Stolephorus sp. in autumn. The high abundance value areas of fish eggs, larvae and juveniles were both located around Damen Island in spring, while were scattered to the outer area relatively in autumn, thus the area around Damen Island should be considered in delimiting the Red-line of ecology. A significant correlation between fish larvae and juveniles and salinity and nutrient was detected in spring. Compared to the data in the early 1990s, species composition and abundance of ichthyoplankton in the study area both have been changing. The abundance of ichthyoplankton around Oujiang estuary was lower than that in other inshore areas along Zhejiang Province.

Key words: fish egg, larvae and juvenile, Oujiang estuary, species composition, ecological distribution