高体近红鲌的生长与繁殖

GROWTH AND REPRODUCTIVE CHARACTERISTICS OF ANCHERYTHROCULTER KUREMATSUI KIMURA

  • 摘要: 高体近红鲌为长江上游的特有鱼类,以2008年5—11月从赤水河赤水市江段采集的540尾高体近红鲌标本为材料,对其生长与繁殖特性进行了研究和分析。结果表明:高体近红鲌鳞片年轮结构呈疏密切割型,年龄特征显著。种群由1—4龄共4个年龄组组成,其中以2龄个体为主。体长分布主要集中在100—160 mm;体重分布主要集中在20.0—50.0 g。总性比为♀∶♂=1.30∶1。体长与鳞径呈直线关系,体长和体重呈幂函数关系且幂指数接近3,基本符合匀速生长类型,体长和体重Von Bertalanffy方程分别为Lt=217.38(1-e-0.2867(t+0.757))和Wt=118.151-e-0.2867(t+0.757)2.8103;生长拐点为2.85龄,拐点对应的体长和体重分别为Lt=140.09 mm,Wt=34.37 g。雌雄初次性成熟年龄均为1龄;繁殖高峰期为6—7月。Ⅳ期雌鱼的绝对繁殖力为950—8655粒,平均值(3087.90±1602.15)粒;体长相对繁殖力FL为10.00—56.20粒/cm,平均值(24.26±10.16)粒/cm;体重相对怀卵量FW为66.08—197.67粒/g,平均值(116.49±32.05)粒/g;卵径频率分布显示高体近红鲌为一次产卵类型。

     

    Abstract: Ancherythroculter kurematsui Kimura is an endemic fish of the Yangtze River, and lives only in the upperreaches of the Yangtze River basin, mainly in Sichuan Province and Chongqing City, China. As an endemic genus, theAncherythroculter Yih et Woo is thought to be important in fish taxonomy and zoogeography studying. Growth is animportant aspect of the ecology and life history of fish, and quantification of growth is frequently a crucial part of fisheriesresearch and management. Unfortunately, few studies have been conducted to describe the growth and reproductivecharacteristics of A. kurematsui. The purpose of this study was therefore to determine age structure and growth characteristicsof A. kurematsui. A total of 540 specimens of A. kurematsui were collected during May to November 2008 fromthe Chishui River, a first-order tributary of Yangtze River. The population age structure and growth characteristics of A.kurematsui were studied. The results showed that the population of A. kurematsui had a relatively simple age structurewhich only contains 4 age classes. The age structure of A. kurematsui was dominated by young individuals, and over95% of the total were age 2 and age 3. Body length range of the population was 81—182 mm, mainly between 100 mmand 160 mm (88.21%), and body weight ranged from 8.7 g to 84.7 g, mainly between 20.0 g and 50.0 g (69.93%). Thetotal sex ratio (♀∶♂) of the population was 1.30∶1, which showed there were much more female individuals thanmale. The fish scale is a kind of appropriate material for age determination; the new annual rings on scales formedmainly in August and September, and all new annual rings were formed before November. The radii of scale (from focusto the flank) took on linear relationship with body length, which could be used for body length back-calculation. Therelationship between body length and radii of scale was described as L=0.0169R+0.0815 (r=0.9305, n=487). There waslittle evidence of differences between sexes. The body length and body weight was in the relation of power function; therelationship of body length to body weight for A. kurematsui could be expressed as W=0.00004 L2.8103 (R=0.9727,n=487). Growth of A. kurematsui took on a constant speed style, which could be described with Von Bertalanffy equation.The growth equation of body length and body weight were estimated as Lt =217.38 (1 ? e?0.2867 (t+0.757) ) and Wt =118.151 ? e ?0.2867(t+0.757)2.8103, respectively. The supreme body length was 217.38 mm, the supreme body weight was118.15 g, the growth parameter was 0.2867 and the theoretical body length zero-point was ?0.7570. The body weightgrowth inflexion point was 2.85, with the corresponding body length of 140.09 mm and body weight of 34.37 g. The fastgrowing period was in the period of 1—2 year old. The average maturing factor of female showed just a peak in Juneduring a year. The absolute fecundities of the matured females varied from 950 to 8655 eggs, and (3087.90 ±1602.15)eggs on average. The relative fecundity to body weight varied from 66.08 to 197.67 eggs/g, with an average of (116.49±32.05) eggs/g. The egg diameter distribution in the ovary was unimodal at mature stage indicating that A. kurematsuiwas a total spawner as opposed to a batch spawner. The results of this study provided important information that the A.kurematsui was being seriously threatened by over-fishing and other reasons. For conservating the resource of A. kurematsui,some measurements must be taken. The conservation strategies include limit fishing biomass, set bidding-fishing periods and protect the key habitat.

     

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