Abstract:
In this study, we recorded the feeding behavior, the growth indicators and the blood indices for 11 months after the spawning of cultured Chinese sturgeon. The growth indicators and the blood samples of the 2 referenced groups were also analyzed, and these 2 groups were in the slow gonad development stage and the same age as the female and male post-spawned individuals. We tested 22 blood indices that included red blood cells (RBC), hematocritvalue (Ht), Hemoglobin (Hb), serum calcium (Ca2+), phosphorus (P3+), magnesium (Mg2+), glutamate-pyruvate (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP), cholinesterase (CHE), magnesium (Mg), total protein (TP), albumin (ALB), globulin (GLB), albumin/ globulin (A/G), total cholestero (CHO), triglycerides (TG), glucose (GLU), serum thyroid-stimulating hormone (TSH), serum T3 (TT3), serum T4 (TT4), serum free T3 (FT3), and serum free T4 (FT3). We found that the re-feeding of the post-spawned sturgeons can be induced with Mallotus villosus, the preferred feed of the two sturgeons before the controlled reproduction. Then the sturgeons started to feed on self-designed diet composed of Mallotus villosus, Scomberomorus niphonius, Loligo chinensis and Penaeus vanname. The feeding of the post-spawned female was initially abnormal due to the weakness, and then the feeding quantity increased to 2.04% of the body weight (to 1.60% of body weight in the post-spawned male at the same time) and the feeding turned back to normal 7 months post-spawning. As the feeding quantity increased over 9 months of recovery, the post-spawned cultured sturgeons showed the higher growth rates of the body length (5.00% and 3.23% for the female and the male respectively) and the body weight (44.16% and 23.30% for the female and the male respectively) than those of the two referenced groups. The concentrations of TT3, TT4, FT3, FT4 and many other blood indices of the two post-spawned sturgeons were lower than those of the two referenced groups in the early recovery, then most of the indices increased nearly to the average levels in the referenced groups, and the levels of TT3 and FT3 were much higher than the average values in the two referenced groups. These implied that the two post-spawned sturgeons were recovered. Our data suggested that refined culture technique could effectively improve the recovery and elevate the growth rate of the post-spawned cultured sturgeon (especially for the female). Our study is also crucial for the reuse of cultured Chinese sturgeon resources and for improving the fecundity after re-maturation.