CAJ | 학술논문

2005-2008年对珠江下游西江江段6个采样点进行鱼类多样性调查,共采集鱼类96种,隶属于13目29科75属,辐斑虫纹东方纯(Takifugu vermicularis)、南方波鱼(Rasbora steineri)、西江鲇(Silurus gilberti)等8种为西江新记录鱼类.西江鱼类群落多度大于1%的种类有17种,前5位依次是鲮(Cirrhina molitorella)、 (Hmiculter leucisxulus)、赤眼鳟(squaliobarbus curriculus)、广东鲂(Megalobrama hoffmanni)、子陵吻虾虎鱼(Rhinogobius giurinus);多度小于0.1的有28种.西江鱼类群落以定居性、杂食性种类为主;与历史比较杂食性、定居性鱼类种类所占百分比上升,肉食性、洄游性、半洄游性鱼类所占比例下降.聚类分析发现西江鱼类群落可以分为3个类群,即:上游类群、中游类群和下游河口类群;物种组成差异分析结果表明,不同江段鱼类群落有明显的差异,相同生境类型江段的鱼类物种相似性较高;上游的物种多样性明显高于下游.通过个体生态学指数(autecology index)分析,西江鱼类群落底层生活、口下位、喜急流生活、肉食性种类受影响程度大,而口端位、杂食性、喜缓流的种类演变成优势种群.航道整治、大规模无序挖沙、河口水体污染、过度捕捞等因素是影响西江鱼类群落变动的主要原因.
2005-2008년대주강하유서강강단6개채양점진행어류다양성조사,공채집어류96충,대속우13목29과75속,복반충문동방순(Takifugu vermicularis)、남방파어(Rasbora steineri)、서강점(Silurus gilberti)등8충위서강신기록어류.서강어류군락다도대우1%적충류유17충,전5위의차시릉(Cirrhina molitorella)、 (Hmiculter leucisxulus)、적안준(squaliobarbus curriculus)、엄동방(Megalobrama hoffmanni)、자릉문하호어(Rhinogobius giurinus);다도소우0.1적유28충.서강어류군락이정거성、잡식성충류위주;여역사비교잡식성、정거성어류충류소점백분비상승,육식성、회유성、반회유성어류소점비례하강.취류분석발현서강어류군락가이분위3개류군,즉:상유류군、중유류군화하유하구류군;물충조성차이분석결과표명,불동강단어류군락유명현적차이,상동생경류형강단적어류물충상사성교고;상유적물충다양성명현고우하유.통과개체생태학지수(autecology index)분석,서강어류군락저층생활、구하위、희급류생활、육식성충류수영향정도대,이구단위、잡식성、희완류적충류연변성우세충군.항도정치、대규모무서알사、하구수체오염、과도포로등인소시영향서강어류군락변동적주요원인.
The survey was made in Xijiang River from 2005 to 2008. Ninety species belonging to 13 orders,29 families and 75 genura were collected from 6 sampling spots. Eight species including Takifugu vermicularis, Rasbora steineri and Silurus gilberti were newly recorded in Xijiang River. There is 17 species whose relative density >1, relative density of 28 species < 0.1. The top 5 species in relalitive density were Cirrhina moitorella, Hmiculter leucisxulus, Squaliobarbus curriculus, Megalobrama hoffmanni and Rhinogobius giurinus. Fish communities were dominated by sedentary species and omnivore species. Compared with the historic data, the proportion of omnivore and sedentary species increased. For carnivore, migratory and half-migratory species declined in number. The fish community of Xijiang River can be distinguished as three cluster, upriver cluster, middle reach cluster and downriver cluster. The results indicated that fish species diversity in Xijiang River were significantly different among different sections. Fish species in similar habitats had higher similarity. The diversity of species in the upper stream is higher than that in the downstream. It also showed that these fish species living at downstream of the river with inferior mouth, relishing riffle, decreased greatly in number especially for the carnivore through the individual ecology index. While these with terminal mouth, omnivore , adept to slow current become the dominated species. It is recognized that sea-route renovation, digging sand without control, water pollution and excessive catching is the key factors to impact fish assemble in Xijiang River.