Abstract:
Cirrhinus mrigala is a key aquaculture species in southern China. In order to enrich its fundamental biological data and provide a scientific basis for its breeding and enhancement in aquaculture, we obtained the fertilized eggs of
C. mrigala through artificial insemination, and observed and recorded the typical characteristics of the embryos and the development of larvae in detail. The results show that
C. mrigala laid drifting eggs. The diameter of the mature eggs was (1.41 ± 0.08) mm, and the fertilized eggs were spherical and light grey in color. After absorbing water and expanding, the diameter reached (4.98 ± 0.67) mm and the expansion coefficient was 353.19%. At the water temperature of 26−28 ℃, the whole embryonic development process lasted 15 h 40 min, and the required cumulative temperature was 438.67 ℃·h. It passed through 7 stages and 32 periods, including the embryonic disc formation stage, egg cleavage stage, blastocyst stage, proto-gut stage, neural embryo stage, organ formation stage and hatching stage. The total length of the first hatchlings was (4.51±0.19) mm.
C. mrigala reached maximum growth rate at 1 day of age with the absolute growth rate and specific growth rate of 1.75 mm·d
−1 and 32.87%·d
−1, respectively. The larvae entered the mixed nutrient period at 41
th hour after emergence from the membrane, and entered the exogenous nutrient period at 4 days of age, which lasted for 9 d to enter the juvenile stage.