Molecular Identification And Community Structure Of Cultrinae Larvae In The Pearl River

The Pearl River is the largest river in the south of China.It is an important freshwater fishery production base and a gene bank for aquatic living resources in China.Its total fishery resources occupy a very important position in the country,but in recent years,with economic growth,over exploitation,and illegal fishing.it has a sharp decline in fishery resources.The Cultrinae is the largest subfamily of Cyprinidae,and they are endemic species in the east of Asia.It has a wide distribution in most of China,and China is therefore regarded as the center of the Cultrinae.There are a large number of Cultrinae Species in the Pearl River Basin,of which,Megalobrama terminalis is a endemic species in the Pearl River Basin.Pseudohemiculter dispar and Pseudolaubuca sinensis have also become important economic species in the Pearl River Basin because of their large total biomass.As an important recruitment group,the fish of early stage of resources have an irreplaceable position in fishery production.This study focuses on the the Cultrinae larva fish.The research contents include the following four aspects:(1)morphological identification:The traditional identification methods of the larvae of the Cultrinae in the Pearl River.Conclude the morphological characteristics Cultrinae of larvae;(2)using the cytochrome c oxidase subunit I(COI)gene as a molecular marker to identified the Cultrinae spices,11 Cultrinae species distributed in the Pearl River have been successfully identified by constructing neighbor-joining trees.(3)Molecular identification techniques are applied to the Cultrinae larvae in the middle and lower reaches of the Pearl River,and statistics indicate that Hemiculter leucisculus(Basilewksy),Pseudolaubuca sinensis Bleeker and Pseudohemiculter dispar are the dominant species,accounting for 34.20%,23.07% and 19.32% of Cultrinae,respectively,their total resources are 1.70x1010,1.15x1010 and 9.60x109 respectively.Megalobrama terminalis,Erythroculter pseudobrevicauda and Parabramis pekinensis are common species,accounting for 11.14%,4.55% and 3.98% of Cultrinae,respectively,their total resources are 5.54x109 and 2.26x109 and 1.98x109,respectively.The total resources of Cultrichthys erythropterus,Culter alburnus Basilewsky,Culter mongolicus mongolicus,Hemiculterella wui,and Sinibrama macrops are low relatively.they all account for less than 2% of the Cultrinae,and the resources of each of them are lower than 1.0x109.The study is one of the important part of the fishery resources monitoring in the Pearl River.