[Spatial niche of major fish species in spring in the coastal waters of central and southern Zhejiang Province, China].

The relative importance index (IRI), mean crowding, niche breadth, and niche overlap (Qik) of major fish species were calculated based on two fishery resource surveys from April to May 2016 (spring) in the coastal waters of central and southern Zhejiang Province. The results showed that there were 24 major fish species (IRI:100), the niche breadth values of which differed greatly and were positively correlated with IRI. The niche overlaps of fishes were extremely low in spring. The total amount of species pairs with niche overlap 0.6 (Qik :0.6) were six in April and five in May, which represented 3.9% and 4.8% of the total pairs, respectively. Results from the redundancy analysis showed that the distribution of major fish species were mainly affected by temperature, salinity, water depth, and dissolved oxygen, which caused ecological differentiation of fish species.