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The oxygen consumption rate (OCR) of juvenile Chinese sturgeon Acipenser sinensis (Body weight, range 5 - 32 g) were determined under different environmental conditions, including water temperature, salinity, illumination intensity and metal ion concentration [Cu2+] by single factor experimental analysis. OCR and opercula frequency (OF) increased with rising of water temperature. The linear relationships between water temperature (WT) and OF with OCR can be described as OCR = 0.018 WT + 0.016 (R2 = 0.988, P < 0.01), OCR = 2.737 OF + 77.726 (R2 = 0.64, P < 0.01), respectively. The acute exposure experiments showed that the OCR also increased initially with an increase in salinity. The linear relationships between salinity (S) and OCR can be described as OCR = 8.1 x 10-5 S3 - 3.01 x 10-3 S2 + 0.0263 S + 0.2729 (R2 = 0.995, P < 0.01). Three days of acclimation to different salinities, the OCRs decreased sharply relative to the first day exposure values. The equation OCR = - 6.29 x 10-4 S2 + 0.0238 S + 0.2797 (R2 = 0.988, P < 0.01) illustrates the linear relationship between salinity and OCRs after 3-day exposure. After 3-day acclimation, the OCRs increased also with increasing light intensity, except for the ambient light group (i.e., 2000 lx) and the group exposed to direct sunlight (i.e., 20000 lx). After 1-day exposure to different Cu2+ concentrations (C), the OCRs decreased rapidly in all of the groups. But the OCR level being gradually different with the increasing of Cu2+ concentration, OCR = 0.237e - 0.09 C (R2 = 0.898, P < 0.01). The results provided us with some useful guide lines which may apply into protection and cultivation management of this endangered species. [ABSTRACT FROM AUTHOR]

It was hypothesized that differences of body shape between pond-reared and tank-reared juvenile Chinese sturgeon Acipenser sinensis may influence their swimming ability, and thus may play an important role in their stocking into the native population. In this study, morphological characters and critical swimming speed (Ucrit) of the pond-reared (body weight, BW = 1426.0 ± 53.8 g, n = 6) and tank-reared (BW = 1201.6 ± 91.4 g, n = 6) size-matched juvenile Chinese sturgeon were measured and compared. The Ucrit of pond-reared sturgeon was 81.3 ± 3.2 cm/s (relative critical swimming speed, Ucrit' = 1.32 ± 0.04 SL/s), which was not significantly higher (P > 0.05) than that of the tank-reared cohort (Ucrit = 76.2 ± 1.9 cm/s, Ucrit' = 1.40 ± 0.03 SL/s). Rearing condition had some significant effects on 12 of morphological characters of the Chinese sturgeon at their early life stage (P < 0.05), but there was only a tendency to be difference between the body shape variations as defined by PC1 (body and caudal length, body depth and caudal filament length) from the principal component analysis (PCA) with 12 size-adjusted morphological characters of the two different cohorts (P = 0.051). There was a significant negative relationship between Lg (Ucrit) (y) and PC1 (x), which could be described by the equation as follows: y = 1.897 - 0.002 x (r2 = 0.372, P = 0.035). These results indicated that rearing condition could not significantly influence the swimming ability associated with body shape of the juvenile Chinese sturgeon, but we should select streamline-bodied juveniles when releasing them into nature. Furthermore, the findings may be useful for a fish way and culvert design due to stringent regulatory requirement [ABSTRACT FROM AUTHOR]