摘要
2008年2月至2009年1月对转基因鱼试验湖泊铜锈环棱螺的种群生态学进行了周年研究。铜锈环棱螺的平均密度和生物量分别为28.96个/m2和17.33 g/m2,丰度最高值出现在4月(34.29个/m2和54.51 g/m2),其次为12月(25.1个/m2和36.18 g/m2)。试验湖泊中铜锈环棱螺在4—7月繁殖,种群中含有4个年龄组,其中2008年龄组占绝对优势。铜锈环棱螺壳长-体重方程为:lg Ww=2.8791×lg SL-3.4227,使用瞬时生长法测算试验湖泊铜锈环棱螺的周年生产量,带壳湿重为12.72g.m-.2a-1,去壳干重为0.74 g.m-.2a-1,P/B系数为0.42。估算试验湖泊2005年至2009年铜锈环棱螺生产量(去壳干重)分别为2.24,2.49,1.50和0.74 g.m-.2a-1。多元逐步回归分析显示总氮对铜锈环棱螺的次级生产量有显著影响,转基因鲤的捕食压力也可能是影响铜锈环棱螺生产量的重要因素。
Bellamya aeruginosa （Reeve） is the predominant macrozoobenthic species and main food source in an artificial lake used for rearing transgenic common carp （ Cyprinus carpio L. ） with the ＇ all-fish＇ growth hormone gene constructs. Knowledge of the life history and production of B. aeruginosa are critical in assessing the predation pressure by transgenic common carp. Between February 2008 and January 2009, the population dynamics and production of B. aeruginosa were studied at monthly intervals at seven stations in the artificial lake situated in Hubei Province, China. The instantaneous growth rate method was applied to determine the production and P/B ratio of B. aeruginosa. Production over the period 2005--2008 was then compared from the calculated P/B ratios. Finally, the important environmental factors influencing production patterns were established via multiple regression analyses. During 2008--2009, annual average density and biomass （wet weight） were 28.96 ind./m2 and 17.33 g/m2, respectively B. aeruginosa recruitment occurred mainly between April and July. A major peak in standing crops was observed in April （34.29 ind./m2 and 54.51 g/m2） , with a minor peak in December （25.1 ind./m2 and 36.18 g/m2）. Based on the peaks in population density and seasonal variations in size distribution of shell-length, the B. aeruginosa population was composed of four cohorts. Growth of the 2005 cohort had nearly ceased, while individuals of the 2008 cohort grew rapidly, with an instantaneous growth rate of 2.34. The 2008, 2007 and 2006 cohorts accounted for 20.2, 52.7 and 25.8% of total density, respectively. Regressions between shell-length and wet weight （Ww） was lg Ww = 2. 8791xlgSL-3. 4227 （n = 96, P〈0. 001 ）. To reduce the error, the growth curves of each cohort （P〈0.05） were also fitted. Using the instantaneous growth rate method, the annual production of B. aeruginosa was calculated at 12.72 g· m-2· a-1 （ wet weight） or 0.74 g· m-2· a-1 （ dry weight without shell）, with a P/B ratio of 0.42. Annual production （ wet weight） for the 2008, 2007 and 2006 cohorts were 6.40 （P/B ratio=2.33）, 1.99 （0.13） and 4.33 （0.37） g· m-2· a-1, respectively. Annual production of the 2008 cohort was ignored because it was only composed of a few aging individuals. Usingthe P/B ratios, annual production （dry weight without shell ） for the 4-year period （2005--2009） was calculated as 2.24, 2.49, 1.50 and 0.74 g· m-2· a-1, respectively, showing a significant steady reduction （ F = 4. 497, P=0. 013 ）. Pearson correlation analysis indicated that water transparency （SD）, total nitrogen （TN）, nitrate nitrogen （NO3- - N） were positively correlated with production （dry weight without shell） （P 〈 0. 001 ） and stepwise regression analysis showed that TN was the key factor influencing production （F=7. 632, P=0. 009）. Water trophic levels and predation pressure by transgenic common carp appear to be responsible for the fluctuations in annual production of B. aeruginosa in this artificial lake. High-level of nutrients may significantly increase B. aeruginosa production, while selective feeding by transgenic common carp had the opposite effect. However, whether production in the artificial lake will continue to decrease with the growth of transgenic common carp requires further research.
出处
《生态学报》
CAS
CSCD
北大核心
2011年第23期7112-7118,共7页
Acta Ecologica Sinica
基金
国家高技术研究发展计划(2005AA60101005)
国家重点基础研究发展计划(2007CB109205)
关键词
铜锈环棱螺
次级生产量
瞬时增长率法
P/B系数
转基因鱼试验湖泊
Bellamya aeruginosa （Reeve）
production
instantaneous growth rate method
P/B ratio
artificial Lake for transgenic fish
