Abstract:A feeding trial was conducted to evaluate effects of dietary vitamin C on non specific immunity of larval and juvenile Symphysodon aequifasciatus with supplement of vitamin C in feed(0-2000.0 mg/kg). When the supplementation ratio reached 500.0 mg/kg(group Ⅴ), the alternative complement pathway (ACP) activity, serum lysozyme activity, phagocytosis index(PI) and phagocytosis percentage(PP) of the fish were significantly higher than that of the control (P<0.05), and they increased over time in the same level. And then the non-specific immune index dropped with the increase of dietary vitamin C above 1500.0 mg/kg (group Ⅷ). It was found that proper level of vitamin C supplement in feed may enhance the nonspecific immunity of the larval and juvenile fish, while lack of vitamin C or over-dose may negatively affect the fish health.
