| Spualiobarbus curriculus belongs to carp family,Leuciscinae subfamily,Squaliobarbus Günther. It is widely distributed throughout Korea, Vietnam, and China. S. curriculus adapt to varaiablehabits. and t The population is enormous in the Pearl River system, and it is an important fishery resource in the middle and lower reaches of the Pearl River. Although the biology, ecology, and genetics of Spualiobarbus curriculus have been studied extensively in China.In this study,experimental ecology and morphological measurement,mitochondrial DNA sequence analysis were used to analyze its morphological diversity, which is the basic knowledge of fishery resource management and conservation. To explore its morphological diversity formation mechanism,garmplasm conservation in Spualiobarbus curriculus and fisheries management as a foundation. The main results and conclusions are as follows:Ecological experiment was conducted to study the allometric growth of Spualiobarbus curriculus larvae and juveniles from Zhaoqing reach in Pearl River. The results showed that after the first feeding, the organs associated to swimming, sensorialand feeding abilty differentiated rapidly, and exhibited allometric patterns. Tail length, headlength and height exhibited positive allometric growth. Trunk length exhibited negative allometric growth until the age of 20 days after opening mouth, afterthere, it exhibited positive allometric growth. Body height exhibited positive allometric growthall the time. For dimensions of organs in head, the growth inflexion points of rostrum length, eye diameter and post-eye head length were at the age of 23, 19 and 16 days. For swimming organs, the allometric growths of dorsal fin, pelvic fin and anal fin were positive, and have the the inflexion point at 18, 19 and 17 days after opening mouth, respectively; but tail fin grew in a positive allometric relation until the age of 14 days after the first feeding. From then tail fin grew negartively allometically. The results indicated that the more faster development of swimming, sensorial, feeding system were than other organs was related to survivalof Spualiobarbus curriculus larvae.We compared the morphology of Spualiobarbus curriculus collected from five river reaches in the Pearl River, China(Laibin, Wuxuan, Guiping, Wuzhou, and Zhaoqing reaches). Twenty-nine morphometric measurements were made for each individual. A cluster analysis(CA) revealed that the five groups were divided into 3 clusters. The first group included fish from Wuxuan, Guiping, and Laibin. The second and third clusters consisted of fish from Wuzhou or Zhaoqing, respectively. The discriminate analysis(DA) suggested that 77.4–96.6% of the individuals were correctly classified into the five reaches. A principal component analysis(PCA) identified six principal components that explained 68.71% of the cumulative variance. The differences between groups were primarily in the head characters dorsal fin, pectoral fin, pelvic fin, and anal fin length. The head of individuals from Laibin and Wuxuan reaches was smalled. whereas fish from the Zhaoqing reach had shorter fins. We explored the molecular analysis of mitochondrial genomes in Spualiobarbus curriculus.172 specimens collected from five river reaches in the Pearl g River were analyzed. Analysis on Cyt b of 1133 bp showed that there were 60 mutation sites in all,27 singleton,33 parsim-info and 49 unique sequences were define. Haplotypic and mucleotide diversity(H)was 0.882±0.017 and 0.00276±0.00025, respectively. Analysis on D-loop of 932 bp showed that there were 84 mutation sites totally25 singleton,59 parsim-info and 86 unique sequences were define. Haplotypic and mucleotide was respectively 0.978±0.005, and 0.00791 ±0.00038, whichsuggested high gengetic diversity. Genetic distance ranged from-0.002 to0.003 in Cyt band from 0.007 to 0.009 in D-loop,which issless than 1% and has no significant variation. The molecular results implied that Spualiobarbus curriculus from five reaches of the Pearl Rvier still belongs to the same group.The morphological and molecular analysis documented that the different features of the five habitats only acted on morphological characters. |
