Abstract: On the basis of four trawl investigations with large plankton net on 20 stations in Laizhou Bay in May and August of both 2014 and 2015, we examined the community structure of ichthyoplankton, including species composition, quantity distribution, and dominant species, as well as its correlation with environmental factors. The results showed that a total of 22 ichthyoplankton taxa were collected during the four voyages. Except for the one un-identified taxon and another one identified to the family level, the remaining 20 taxa belonged to 20 genera, 16 families, and 8 orders. Dominant taxa showed substantial seasonal changes. Results from the multivariate analysis of the correlation between the quantity distribution of ichthyoplankton and environmental factors showed that salinity had a significant influence on the number of eggs and temperature had an obvious effect on the number of larvae. The number of larvae was significantly correlated with dissolved oxygen (DO), nitrite, inorganic nitrogen and activated phosphate contents (P<0.05), ammonia nitrogen (NH₃-N) and chlorophyll-a contents (P<0.01). The density of copepods had a significant positive correlation with the number of eggs (r=0.479,P=0.032), but had a significant negative correlation with the number of larvae (r=-0.510,P=0.022).

Key words: enzyme stoichiometry, soil enzyme, environmental factor, altitude, Biolog