A Study On The Status Of Fish Resources In Major River Systems Of Gansu Province And Genetic Diversity Of Onychostoma Macrolepis

An extensive fish resource survey was done in Gansu Province for two years,from 2020 to 2021,on the main water systems of the Yellow River Basin,Yangtze River Basin,and inland river basins.The goal was to understand the diversity and distribution characteristics of fish in Gansu Province and assess the level of genetic diversity of Onychostoma macrolepis,an endangered fish in Gansu Province,and provide a reference base for effective endangered fish protection and genetic breeding.The following are the research’s primary findings:1.A total of 3,571 fishtails were caught in this resource survey.These were recognized as 41 species belonging to 4 families,10 other families altogether 30 genera.Carp-shaped fish have the most species,followed by perch-shaped fish,and others with the least.Onychostoma macrolepis,Triplophysa siluroides,and Schizophorax davidi,three national-level significant protected wild fish species,were studied in the current study.According to statistics,the number of fish species in the three major watersheds,the Yangtze River Basin has the most,with22 species,followed by the Yellow River Basin and the interior river basin,with19 and 20 species,respectively.The three main watersheds’ ecological types have the most omnivorous and benthic sedentary fish.Their reproductive habits are mostly sticky egg-laying fish;the results of fish flora analysis are mainly based on the Central Asian mountain and river plain complex taxa,followed by the ancient Neoproterozoic complex taxa.2.The Shannon-Wiener index,Margalef index,and Pielou index were employed to examine the three watersheds’ species diversity.The findings revealed that the diversity of fish species and distribution features of the three main watersheds of Gansu province’s differed significantly,The Yangtze River Basin has the highest Shannon-Wiener diversity index of fish(H=3.66),followed by the inland river basin(H=2.01),while the Pielou uniformity index in the Yellow River basin has the lowest(J=0.427);among the Shannon-Wiener diversity index of each of the three river basins,the Yangtze River Basin’s Liangdang-Huixian section has the highest index,while the Yellow River Basin’s Chemuxia-Damiao section has the lowest.The fish habitat differences between the Yellow River Basin,the Yangtze River Basin,and the inland river basin are significant(P<0.05).There is a degree of fish species differentiation if we compare the Yellow River Basin to the Yangtze River Basin and the inland River Basin to the Yangtze River Basin,according to the diversity results.3.Statistics on the quantity and biomass of fisheries in various watersheds demonstrate more substantial variations between fish species in the Yellow River basin.In contrast,there are no significant differences between fish species in the Yangtze River basin,indicating that fish diversity in the Yangtze River basin is greater than that of fish in the Yellow River basin;Pseudorasbora parva and Carassius auratus are non-indigenous fish in Gansu province but has become the dominant species in the inland river basin,according to the survey.Foreign species are seen to be a hazard to the growth and development of local indigenous fish in Gansu Province.They pose a certain degree of threat.According to an examination of the body length and body weight of endangered fish.The miniaturization and miniage of endangered fish and key economic fish in Gansu Province is relatively significant.4.The genome of Onychostoma macrolepis was screened using three distinct microsatellite sites,yielding 11 microsatellite sites: Pra 13,Pra 14,Pra 20,Pra 36,Pra 54,Pra 60,OSI 45,MIVA 11,BJY 57,BJY 63,and BJY 96.The number of alleles is between 3-11,and the average number of alleles is 7.091;the observed heterozygosity is 0.316-0.970;the expected heterozygosity is 0.603-0.857,with an average value of 0.7597;the polymorphic information content(PIC)is between 0.542-0.838,with an average value of 0.7196;the polymorphic information content(PIC)is between 0.542-0.838,with 0.7196 as an average value.Hardy-Weinberg equilibrium test findings revealed that,with the exception of sites BJY 63,Pra 36,and Pra 60,all of the remaining 8 sites diverged from the equilibrium.5.From more than 100 pairs of microsatellite primers,9 stably amplifiable microsatellite sites with high polymorphism were chosen for this investigation.The genetic diversity patterns of two populations of Onychostoma macrolepis were examined using the abovementioned 9 polymorphism sites.The number of alleles detected at each site ranged from 3 to 10;the expected heterozygosity of site BJY 63 in the Hongyahe and Meiyuan river Onychostoma macrolepis populations was higher,but the expected heterozygosity of site Pra 36 in the Hongyahe population was the lowest,around 0.551;the polymorphic information content(PIC)was 0.469-0.796.Except for Pra 36’s with lower polymorphism,the remaining 8 sites were all highly polymorphic(PIC>0.5).Based on the above data,it can be stated that the Onychostoma macrolepis population in this research has a high level of genetic diversity.In summary,the findings of this study complete data on Gansu Province’s key fish resources while also providing a theoretical reference for the conservation of endangered fish variety.