| In this study,347 samples of Pseudecheneis sulcatus were collected in the lower reaches of the Yarlung Zangbo River from April to October of 2017 and 2018 to study their biological characteristics in terms of reproduction,age,growth and feeding habits,so as to understand the life habits of Pseudecheneis sulcatus and provide basic data for its artificial reproduction and resource protection.The results are as follows:1. There were nine age groups of collected samples,and the most individuals was2-5 year-old accounting for about 66.12%of total samples.The relationship growth showed nosignificant between females and males.The sample body length range is50.00?144.00mm,and the average body length is 99.07±18.66 mm,The body weight distribution ranged from 3.82?65.61g with an average of 25.96±14.70 g.2. Contrast,found that the spine and micro otolith as age identification of material for Pseudecheneis sulcatus,micro otolith appraisal success rate was 14.28%,while the identification success rate of vertebrae was 96.43%.Vertebrae were selected as age identification materials of Pseudecheneis sulcatus.3. The straight line relationship between the radius of vertebra and body length was L=62.88R+40.69(R~2=0.89,n=183).The relationship between body length and pattern,pattern fitting effect Logistic growth,Von Bertalanffy growth of three kinds of growth function pattern,Comparing the fitting effect of growth equation by AIC criterion and BIC criterion,The growth pattern of P.sulcatus was formulated by Von was 7.1 years,in which total length and body weight were 124.64 mm and 45.52 g.4. The fecundity of 78 female breeding parents of Pseudecheneis sulcatus using individual biological methods.The results showed that the breeding population of Pseudecheneis sulcatus consisted of 6 age groups from 4 to 9 years old,and the absolute fecundity(F)ranged from 346.00 to 799.00,with an average of 498.00.The relative fecundity of body length(F_L)ranged from 3.36 to 5.53 grains/mm,with an average of 4.45±0.47 grains/mm,and the relative fecundity of body weight(F_W)ranged from 20.69 to 92.80 grains/G,with an average of 41.33±16.18 grains/G.5. The regression equation ofbody weight with body length was as follows:W=0.6632L-54.924(R~2=0.9215).The regression equation of absolute fecundity with body length was as follows:F=7.229ln L-302.01(R~2=0.913),The regression equation of absolute fecundity with body weight was as follows:F=10.343W+307.16(R~2=0.889).The regression equation of absolute fecundity with body length,gonadal maturationcoefficientandfullnesswasasfollows:F=-446.369+6.567L+480.757GSI+10815864.49K(R~2=0.930),and Multiple linear standardized regression analysis equation of relative fecundity of body weight and body length,body mass,ovary weight,gonad maturation coefficient,fertility as follows:F_W=112.999-0.565L+3.488W-1.228Wn-15.348Wo+213.172GSI-1.358A-3860803.248K(R~2=0.938).According to the analysis of spawning habits,gonadal development and egg diameter composition,the macular pleura is judged to be a one-time spawning fish.6. It was found that the main food sources of Pseudecheneis sulcatus were algae,aquatic insects,protozoa,rotifer,Cladocera,copepod,organic debris,sediment,etc.Algae and aquatic animals are the main food sources.The ingestion intensity and food composition of smaculatum vary with seasons.The ingestion intensity in summer and autumn is higher than that in spring.The main food composition in spring and summer is algae,and the intake of aquatic insects in autumn is higher.At the same time,the food composition of different body length groups was different.Algae was mainly ingested at 50-80mm,and no ingestion of aquatic insects was found in the food composition.However,aquatic plants such as algae and aquatic insects,copepods and Cladocera were ingested at 80-110mm,110-140mm and 140-170mm,and there was no significant difference in the food composition among the three groups.Compared with other groups,there was no change in food species in the group with body length larger than 170mm,and aquatic insects accounted for the largest proportion in all food.Growth and seasonal changes are the main factors that affect the food changes of the Pseudecheneis sulcatus. |
PDF Full Text Request