Abstract
Aiming to understand the genetic diversity of Culter and Cultrichthys fishes in West Dongting Lake following the implementation of fishing ban, this study analyzed the genetic diversity and phylogeny of five Cultrinae species based on mitochondrial Cytb and COI gene sequences. For Cytb, 50 haplotypes were identified with high overall genetic diversity (H(d) = 0.954, π = 0.04765, K = 53.506). Similarly, COI yielded 48 haplotypes (H(d) = 0.950, π = 0.03251, K = 36.414). Interspecific comparisons revealed that Culter mongolicus and Culter alburnus exhibited the highest genetic diversity, while Cultrichthys erythropterus showed the lowest. Demographic inferences from neutrality tests and mismatch distribution analyses differed between markers. Based on Cytb, populations of C. erythropterus and C. oxycephaloides appeared to be at neutrality, whereas C. mongolicus, C. alburnus, and C. dabryi significantly deviated, suggesting historical expansion. Mismatch distributions supported recent expansion in C. mongolicus and C. dabryi. In contrast, COI-based neutrality tests indicated expansion in C. mongolicus, C. alburnus, and C. dabryi, with mismatch results confirming this signal for C. dabryi. The negative values of Tajima's D and Fu's Fs observed across all five species reflect an accumulation of low-frequency alleles within populations, which may indicate a recent rapid demographic recovery. These findings provide genetic evidence that the genetic diversity of these Cultrinae species has likely been recovering since the fishing ban took effect on 1 January 2020. Further conservation strategies are therefore recommended to promote population recovery and enhance genetic diversity.