【作者】 程光平；

【导师】 高天翔；

【作者基本信息】 中国海洋大学 ， 渔业资源， 2011， 博士

【摘要】 巴马繐唇鲃（Crossocheilus bamaensis Fang, sp.nov.）是我国固有、主产于西江水系红水河的土著名贵小型经济鱼类。以固着藻类为食。体肥肉嫩，富含脂肪，有―油鱼‖之称。近年来，由于“酷渔滥捕”、人为的扰动、拦河筑坝及生存环境的改变等因素影响，巴马繐唇鲃渔获量急剧减少，资源量濒临衰竭。若恢复和保护巴马繐唇鲃鱼类资源，必须对现有资源进行保护，尤其是加强对巴马繐唇鲃的隔离保护，建立巴马繐唇鲃种质资源天然生态库。同时，通过人工繁殖并实现“人繁”苗种的放流，以补充江河群体数量，加快巴马繐唇鲃鱼类资源的恢复进程。要实现这一过程，系统了解和掌握巴马繐唇鲃生物学及遗传学状况尤为重要。本文以2006至2007年野外采集的巴马繐唇鲃样本为基础，利用表型性状度量与分析、水平凝胶电泳技术、mtDNA细胞色素b （Cyt b）序列分析、控制区序列分析和AFLP分析等技术，从年龄、生长、性腺发育、繁殖、遗传特性和资源状况等方面研究其生物学及遗传学状况，获得如下结果：1、西江水系的巴马繐唇鲃和柳城繐唇鲃的18个形态学可量性状差异显著（P< 0.05）：巴马繐唇鲃的头长/体长、眼径/体长、眼间距/体长和眼后头长/体长4个性状指标显著小于柳城繐唇鲃（P < 0.05），其余性状指标显著大于柳城繐唇鲃（P < 0.05），而吻长/体长和尾柄长/体长2个可量性状变量无种间差异（P >0.05）；巴马繐唇鲃侧线鳞数（40～42）显著大于柳城繐唇鲃（37～39），其余分节性状在种间无显著差异。2、巴马繐唇鲃巴马种群的头长/体长、吻长/体长、吻至胸鳍起点/体长、吻至腹鳍起点/体长等4个变量显著小于都安种群（P < 0.05），表现出同种不同地理种群上的差异，而其余性状变量无地理种群间的显著差异（P > 0.05）。两地理种群表型特征性状的性别差异为：①同体长的都安种群，雌性的体重、体高及眼后头长显著大于雄性；②同体长的巴马种群，体重、体高及眼后头长雌雄无显著差异，但尾柄长雄性显著大于雌性。3、巴马繐唇鲃1龄性腺发育至Ⅱ～Ⅲ期，尚未发育成熟，属幼鱼生长阶段；2龄性腺发育至Ⅲ～Ⅴ期，成为繁殖群体；3龄成为繁殖群体的主体；雌雄鱼性成熟年龄均为2龄，其中雌鱼最小性成熟个体体长8.68 cm，体重17.25 g；雄鱼最小性成熟个体体长8.04 cm，体重11.20 g。卵巢成熟系数每年2月开始呈上升趋势，6月达到峰值，6月后逐渐下降，10月出现最低值，此后又逐渐回升，至次年6月再次出现峰值，呈现周期性变化。4、巴马繐唇鲃的繁殖力（相对怀卵量和成熟系数）与年龄关系密切：从1龄至3龄个体繁殖力逐渐升高，3龄后，随着年龄的增长，个体繁殖力逐渐下降，揭示3龄为最佳繁殖年龄。繁殖期为每年4～8月，其中5～6月为繁殖旺季。巴马繐唇鲃属一年一次产卵类型，其成熟卵子青色，圆球形，微黏性。产卵场为砾石、卵石底质、间有泥沙，岸边浅水带长有水草、水质较清澈并有一定水流的河床。5、巴马繐唇鲃鳞片属圆鳞呈铲形，鳞长反映了鱼体生长状况，体长（L）与鳞长（R）呈直线关系L = 1.7824 + 67.67 R；体长体重（L-W）关系式为：W = 0.0334 L^2.8302 （r = 0.9934, n = 289）幂指数b = 2.8302，近似于3，揭示其体重与体长近似立方成正比关系，属均匀生长类型。生长方程较好地拟合了其生长特点，生长规律基本符合von Bertalanffy的生长方程。体长及体重生长方程为：L_t = L_∞(1-e^-k（t-to）) =16.4677×(1-e^{-0.2190（t + 1.177）})W_t = W_∞(1-e^-k（t-to）)^b=92.6963×(1-e-^{-0.2190（t + 1.177）2}.83026、巴马繐唇鲃年龄与体长和体重的生长关系密切：体长增长率1龄最快，2、3龄后下降；体重增长率2龄前较慢，3龄最快，达到最大值，属旺盛生长阶段；4龄后生长速度开始趋缓。生长拐点年龄ti = 3.57龄，略大于性成熟年龄。7、选用5对选择性引物对巴马、都安和来宾3个种群共计86尾巴马繐唇鲃进行了AFLP分析，各种群内检出的总位点数分别为308、304和296，其中多态位点数目及其比例分别为58 （18.83%）、52 （17.11%）和45 （15.20%）。巴马种群的多态位点比例最高，都安种群次之，来宾种群则最低；以Shannon多样性指数表示的遗传变异度为：巴马种群（0.0843）>都安种群（0.0798）>来宾种群（0.0728），其中有63.35%的遗传变异源于种群内，36.65%的变异源于种群间。巴马繐唇鲃种群间的遗传分化系数为27.93%，分化程度较低，遗传多样性处于较低水平。8、巴马繐唇鲃在MPI*位点表现为多态，多态位点比例为0.0769，观测杂合度为0，平均预期杂合度为0.0059，平均有效等位基因数目为1.1361，Hardy-Weinberg遗传偏离指数d为-1，表明其杂合子严重缺失。巴马、都安和来宾三个种群的402 bp的Cyt b基因片段中，仅存在1个单倍型，没有插入与缺失。单倍型多样性指数及核苷酸多样性指数均为0，各种群多态性水平较低，遗传多样性非常贫乏。更多还原

【Abstract】 Crossocheilus bamaensis Fang, sp.nov. is a native rare economical fish, itparticularly exists in China, primarily exist in Hongshui River which belongs toXijiang drainage system. It is fed with periphytic algae. It is called ?oil fish‘because itis fat and rich in lipid. Recent years, because of the influence of some factors, such asheavyfishing, human perturbing and building diversion dam, have cut off the migratechannels and have changed the living environment, all of these led the decrease ofcatching fish dramatically and the resources are close to prostration. In order torecover and protect the resources of C. bamaensis, the protection of the existingresources should be enhanced, especially enhance the isolation and protection of C.bamaensis, build the native genetic conservation. At the same time, we should applythe artificial propagation to supplement the populations in the river, and to speed upthe process of resources recovery. It is important to understand and master thebiological and genetic situation to achieve this process. In this article, based on thesamples collected in 2006 and 2007, the phenotypic characters are measured andanalyzed, by using horizontal slab gel electrophoresis technology, mtDNA and Cyt-bsequential analysis, D-loop sequential analysis and AFLP analysis, researched thebiological and genetic situation of age, growth, gonad development, breeding, geneticcharacters and resources situation, the results are as follows:1、There are 18 morphological characteristics of Xijiang drainage system C.bamaensis and Liucheng Crossocheilus appear to significant difference （p<0.05）,head length/body length, eye diameter/body length, eye distance/body length and headlength after eyes/body length of C. bamaensis are significantly smaller than LiuchengCrossocheilus （p<0.05）, other character indexes are significantly larger than LiuchengCrossocheilus （p<0.05）, while tongue length/body length and caudal pedunclelength/body length have no interspecific difference （p>0.05）, the scale amount of sideline of Crossocheilus bamaensis（40⁴2） is significantly larger than LiuchengCrossocheilus （37³9） （p>0.05）, their segment character have no interspecificdifference.2、The four variable for head length/body length, snout length/body length, snoutto origin of pectoral fin/body length and snout to origin of pelvic fin/length of Ba ma population significantly smaller than Du an population （P<0.05）, which displays thegeographical differences of the same group, but the other characters variables have nogeographical differences （P<0.05）. The sexual different phenotype traits of twogeographical populations:①The female‘s body weight, body height and eye length ofthe same body length of Du an population are significantly larger than males.②Thebody weight, body height and eye length of the same body length of Ba ma populationare no significant differences between female and male. However, the male‘s caudalpeduncle length is significantly larger than female.3、The age 1 of C. bamaensis belongs to juvenile growing stage without maturedgonads in II～III time. The age 2 reaches breeding community with III～Ⅳtimedeveloping gonads and age 3 is the main group for the breeding community. Thematured age of C. bamaensis is two age. The body length is 8.68cm and weight is17.25g for the minimum matured female. The body length is 8.04cm and weight is11.20g for the minimum matured male. The ovarian mature coefficient has theperiodic phenomenon rises from February to the peak value in June and drops fromthat time to the minimum value in October. Hereafter it gradually rises again. It willpresent the peak value once more in June next year and will enter the new cycle.4、The reproductive capacity of C. bamaensis is more closely with the age（relative fecundity and mature coefficient）: the individual reproductive capacityelevates gradually from 1 to 3 age. After age 3, the individual reproductive capacitydrops gradually along with the age growth. So age 3 is the best reproductive age. Thebreeding season of C. bamaensis is from April to August and the breeding busyseason is May and June, which belong to an oviposition type for 1 year. The matureegg of C. bamaensis is green, round sphere and micro stickiness. The spawninggrounds is the gravel, pebbles, sand between substrate and have the water plant, clearwater and certain shore shallow water zone.5、The scale of C. bamaensis is shovel-shaped. The length of scale reflects thegrowth condition. Body length （L） and scale length （R） have linear relations （L =1.7824 + 67.67R）. The body length （L） is positively correlated with the weight （W）like the cube relations, which belongs to the uniform growth type﹝W=0.0334L^2.8302（r=0.9934,n=289），power exponent: b = 2.8302，similar to 3﹞. The growth equationfits its growing characteristic well and the growing rule has coincided with thegrowing equation of von Bertalanffy basically. The growing equation between body length and body weight :L_t = L_∞(1-e^-k（t-to）) =16.4677×(1-e^{-0.2190（t + 1.177）})W_t = W_∞(1-e^-k（t-to）)^b=92.6963×(1-e-^{-0.2190（t + 1.177）2}.83026、The growing relationship between the age of C. bamaensis and body length andweight is very close. The fastest growth rate of body length was at age 1 and declinedafter age 2 and 3. The growth rate of body weight increased slowly before age 2 andreached the maximum at age 3 for a high growth stage then grew slowly after age 4.The age of growth inflection point （ti） is 3.57 age, larger than the age of sexualmaturity.7、A total of 86 C. bamaensis from Ba ma, Du an and Lai Bin populations wereanalyzed by the AFLP of DNA with five pairs of selective primers. The total sites ofthis 3 populations were 308, 304 and 296 and the number of polymorphic loci andthe rates were 58（18.83%）, 52（17.11%） and 45（15.20%）. The highest rate ofpolymorphic locus was Ba ma population, next was Du an population and the Lai binpopulation was the lowest. The degree of genetic variation showed by Shannon‘sdiversity index: Ba ma population （0.0843） > Du an population （0.0798） > Lai binpopulation （0.0728）. 63.35% of genetic variation came from internal populations and36.65% from external populations. The genetic differentiated coefficient of C.bamaensis population was 27.93%. Both the differentiated degree and the geneticdiversity were at a low level.8、The rate of polymorphic locus called MPI* of C. bamaensis was 0.0769 and theobserved heterozygosity was 0, the average expected heterozygosity was 0.0059 andthe average number of effective alleles were 1.1361. The genetic deviation index （d）of Hardy-Weinberg was -1, which shows serious heterozygotes. Just one haplotypeand no insertion and deletion exist in the Cytb gene fragment for 402bp of Ba ma, Duan and Lai bin populations. The diversity indices of haplotype and nucleotide were 0.Both the polymorphism and genetic diversity were very poor.更多还原