Morphological Studies Of Allometric Growth,different Geographical Populations And Bone Morphology Of Qihe Carassius Auratus

Early allometric growth of fish develops preferentially those organs which have important effects on the survival of the individual.Different organs have different characteristics of allometric growth,so it is an important growth strategy for the fry to adapt the requirements of habitat environment.Qihe river Carassius auratus is provided with fast growth rate,delicious taste and economic high growth,which is specie of unique quality.Therefore,in this thesis,the characteristics of allometric growth from hatching to 20 days are researched;the early development pattern of Qihe river Carassius auratus are discussed.Simultaneously,the skeletal morphology of head in Qihe river Carassius auratus from different populations is described and analyzed,and the characteristic variables of different populations are extracted.This study fills the gap of the basic data of the growth characteristics in Qihe river C.auratus from hatching to 20 days and completes the research of the skeletal morphology of different populations,which accumulate basic data in the early stage of production and breeding for Qihe river C.auratus.The larvae and adult Qihe river Carassius auratus are tested;bone specimens are prepared by conventional methods;morphological variables of Qihe river C.auratus are measured according to the literature.Total length,head length,eye diameter,snout length,trunk length,head height and body height are measured;the data is computed by SPSS 20.0.One-way analysis of variance,discriminant analysis,principal component analysis,curve fitting,etc.are involved.1.The early development of Qihe river Carassius auratusThe fish of experiments comes from aquaculture base of Fisheries College in Henan Normal University.The test is conducted in 5-6 month,2015.The characteristics of allometric growth from hatching to 20 days are researched.The results show that the larvae is growing fast under the condition of 18-22?.The results of comparison among different models indicate that the linear growth model is more suitable for the farvae.The results from allometric growth of each variables show that the growth of head is faster than that of trunk in the larvae stage.Positive allometric growth of head is prepared for feeding and respiration.The trunk length increases slowly in the larvae stage,this may be related to the development of digestive system satisfying nutritional needs of rapid growth.Thus,Qihe river C.auratus is sensitive to temperature effects in the early development,and some organs develop in priority play a key role in their survival.2.The comparison of the morphology of Qihe river Carassius auratus from different populationsQihe river C.auratus in the test are collected from Qixian,Linxian and Xinxiang.A total of 10 quantitative trait variables are calculated including total length,body length,body height,body width,etc.The results reveal that there are significant difference existing in six proportional characters(body length/ total length,body height/ total length,head length/ total length,interorbital distance/ total length,caudal peduncle length/ total length,base length of dorsal fin/ total length)among the three populations of Qihe river C.auratus.Three notable variates like body height/ total length,caudal peduncle length/ total length and base length of dorsal fin/ total length are extracted by the analysis of discriminant functions to establish two discriminant functions.The original sample test and cross-validation test are used to examine these functions,with the total classification accuracy of 100% and 97.5% respectively.Three factors whose cumulative contribution rate is 76.7% are extracted by principal component analysis.The morphological difference of Qihe river C.auratus in Qixian population and Linxian population is small,however,the morphological difference of Qihe river C.auratus from Xinxiang population is larger than that from the former two populations.The results suggest that the morphology of Qihe river C.auratus exist differences to some extent.The origin of different populations could be confirmed by some characters of morphology.3.The comparison of the morphology of pharynx and head bone pieces in Qihe river C.auratusThe bones of pharynx,operculum and cleithrum in Qihe river C.auratus from Qixian population,Linxian population and Xinxiang population are studied.And fifteen linear variables from the bones are measured.The results show that thirteen variables are different in groups,which exists in the populations of Xinxiang and Linxian or Qixian and Linxian.There are no significant differences existing in another two variables.The results suggest that the variables from pharyngeal bone are relatively stable,which are generally less prone to mutate.Three factors whose cumulative contribution rate is 88.8% are extracted by principal component analysis.Therefore,the main factors of morphological differences of head in different populations are found out.