Carbon, nitrogen and phosphorus stoichiometry in Japanese anchovy (Engraulis japonicus) from the Huanghai Sea, China

摘要

Generally, nutrient cycle is closely related to the element distribution in biomass and the population dynamics in ecosystems. Carbon, nitrogen and phosphorus in Japanese anchovy (Engraulis japonicus) of different body lengths from the Huanghai Sea (Yellow Sea) were determined to better understand their variability and reasons during its life history. The mean content was 45.12%, 10.12% and 2.02% for C, N and P, respectively. Significant differences in C, N and P elemental composition were found among different sizes, which could be explained by varying proportions of storage compounds in whole body fish, and varying degrees of ossification. Considering abundant resources in Japanese anchovy, it was an important P-pool in the cycle of P. Moreover, the excreted N/P ratio was significantly different in fishes of different sizes, especially at high gross growth efficiency. In the past two decades, overexploitation tended to cause smaller body length in the community structure of anchovy, which presumably changed the nutrient cycle in food webs of the Huanghai Sea. Exptrapolation of the results indicates that Japanese anchovy may be important for conveying nutrient in the Huanghai Sea.