The distribution of MMWPAHs on a wet weight basis was found higher in crucian carp selleck products and was approximately equal in the other three species. A decreasing pattern of HMWPAHs distribution was found among crucian carp, bighead carp, carp, and grass carp, respectively. However, these differences were not significant at a 95% confidence level (P > 0.05), under the two-way ANOVA.Figure 3Wet weight contents of (a) total PAHs (PAH16), (b) LMW-PAHs, (c) MMW-PAHs, and (d) HMW-PAHs in four fish species.Residual PAH levels in various tissues are shown in Figure 4. The distribution of total PAHs and LMWPAHs was found to be highest in the brain, lower in the bladder and roe, and the lowest was found in the liver and muscle.

With regard to the distribution of MMWPAHs, the highest levels of content were found in the bladder, lower levels in the brain and roe, and the lowest were found in the liver and muscle. Finally, the distribution of HMWPAHs was found to be highest in the roe, lower in the brain, and the lowest was found in the bladder, liver, and muscle. The result of the two-way ANOVA is shown in Table 4, which showed that residual levels of PAHs on a wet weight basis were tested to be significant under a 95% confidence level (P < 0.05). Figure 4Wet weight contents of (a) total PAHs (PAH16), (b) LMW-PAHs, (c) MMW-PAHs, and (d) HMW-PAHs in four fish tissues.Table 4ANOVA results of wet weight-based PAH contents.3.3. PAH Distribution in Various Fish Tissues on a Lipid-Normalized Weight BasisThe distribution of sixteen types of PAHs in various fish tissues on a lipid-normalized weight basis shown in Table 5 ranges from 93.

62ng?g?1 to 8203.43ng?g?1, with a mean value of 1204.18ng?g?1 �� 144.16ng?g?1. Figure 5 shows the differences on a lipid-normalized weight basis of the various species. Residual levels of PAHs on a lipid-normalized weight basis were found to be highest in bighead carp, lower in crucian carp, and the lowest in carp and grass carp. The distribution of total PAHs, LMWPAHs, and MMWPAHs shared similar patterns. According to the two-way ANOVA results (Table 6), the residual level of PAHs on a wet weight basis was tested to be significant under a 95% confidence level (P < 0.05). This is most likely related to the different feeding habits of the various species. Bighead carp is a filter feeder, feeding on zooplankter, leading to the highest residual levels of PAHs on a lipid-normalized weight basis.

Crucian carp and carp are omnivorous fish and therefore the residual level of PAHs on a lipid-normalized weight basis was found to be lower. Grass carps are herbivorous, Brefeldin_A and they were found to contain the lowest residual level of PAHs on a lipid-normalized weight basis.Figure 5Lipid normalized contents of (a) total PAHs (PAH16), (b) LMW-PAHs, (c) MMW-PAHs, and (d) HMW-PAHs in four fish species.