| Cobitis sinensis,belonging to Cypriniformes,Cobitididae,Cobitis.In this study,from October 2017 to October 2019,748 samples of Cobitis sinensis distributed in Wuyang river of Guizhou were selected as the research object.We studied in the following areas:age,growth,feeding habit,reproduction,population resources assessment.The main objective of the study is to provide scientific information for local fisheries management and fishery regulation based on the ecosystem.The main results were as follows:1.October 2017 to October 2019,748 Cobitis sinensis samples were collected from Wuyang river of Guizhou.The range of standard length,body weight and age was 56.5?102.24mm,1.27?13.7g,1?4 years.The three age materials,scale,vertebrae,and operculum were used for age identification.The age characteristics of the operculum are not obvious,and the scales are relatively clear.In the discrimination rete,the scales(94%)are higher than the spine(71.3%),and the anastomosis rate the scale is also higher than the spine,operculums are not obvious.The length-weight relationship was:W=4×10-6L3.2444,respectively.The von Bertalanffy growth equations was:Lt=114.16[1-e-0.11(t+1.2)].Wt=18.91[1-e-0.11(t+1.2)]3.244.The inflexion age on the growth rate curve for weight of was 9.03 years old,77.12mm and 5.3g.2.According to the basic bait survey of Cobitis sinensis in the Wuyang River,there are a total of 46 species of phytoplankton in 32 genera and 6 phytoplankton,the Bacillariophyta has the most species,followed by the Chlorophyta and Cyanophyta,the species of Cryptophyta,Euglenophyta and Xanthophyta are the least;there are 39 species of zooplankton in 35 genera and 4 phyla,the species of Protozoa the most,followed by Rotifer,the species of Cladocera and Copepods are the least.Studies on the feeding habits of Cobitis sinensis showed have the selectivity for bait.The a higher selection of diets for G.subclavatum,N.graciloides,C.tumida and A.falcatus var.mirabilis.3.In this study,Cobitis sinensis distributed in Wuyang river of Guizhou Province were selected as the research object.The reproductive biology of Cobitis sinensis were studied in order to provide scientific basis for artificial breeding,resource protection,resource development and utilization.A total of 381 loach samples were collected from Wuyang River from November 2017 to May 2018.The body length(L)range was 58.9-100.2mm,and the body weight(W)range was 2.0-13.7g.The scales were used as materials for age identification,and their ages ranged from 1 to 4 years old.The samples were dissected for sex identification and gonadal staging.Among the 381 samples,23 were unidentifiable for its sex,248 were males and 110 were females.The results showed that the individual absolute fecundity F 542-2865 eggs,the individual relative fecundities FL and FW were 6.6-28.6 eggs/mm and 99.8-490.7 eggs/g respectively.Through field investigation,it is showed that Cobitis sinensis are mainly in shallow water with sandy bottom,fresh water quality,slow water flow and abundant aquatic plants.The spawning of Cobitis sinensis is from May to August,peaking in mid-May to mid-June.The research results show Cobitis sinensis is urgent to conduct resource protection4.To obtain an understanding of the resource status of Cobitis sinensis,748 samples were collected at Wuyang river of Guizhou.The range of standard length and body weight were 56.5?102.24mm and 1.27?13.7g.Stock biomass were estimated by length-based cohort analysis(LCA),while population dynamics was evaluated by Beverton-Holt dynamic model.The results showed that the natural mortality coefficient,total mortality coefficient,and fishing mortality coefficient were 0.24a-1,0.38a-1and 0.14a-1,respectively.The current exploitation rate was 0.37.The results revealed that the quantity of Cobitis sinensis was 7786.52,3260.58and 2552.1 from 2017 to 2019 in sequence. |
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