摘要
基于2011年5月至2012年4月(12月和翌年1—2月冰期除外)在渤海莱州湾逐月采集的数据资料,分析莱州湾强壮滨箭虫丰度空间分布和体长的季节变化,估算其生产力和摄食率,以掌握其种群动态特征,为评价该种在莱州湾生态系统结构功能中地位提供参数和依据。结果显示:强壮滨箭虫丰度和生物量年变化曲线为双峰型,最高峰出现于5月,次高峰出现于8—9月;4 mm和15 mm体长的个体分别是丰度和生物量的主要贡献者。生产力估值为0.25 mg C m^(-3)d^(-1),摄食率估值为0.88 mg C m^(-3)d^(-1)。种群月均体长以3—4月最高(>10 mm)、5月和11月最低(<5 mm);月均体长与月表层水温、盐度呈负相关。春季5月、夏季7—8月和秋季10—11月中,小型个体丰度所占的比例较高,应为种群数量增长期。各月的体长频数分布可分辨出平均体长<5mm(Cohort Ⅰ)、介于5—10 mm(Cohort Ⅱ)和>10 mm(Cohort Ⅲ)的3个同生群。Cohort Ⅲ和Cohort I高丰度区的表层水温和盐度分别介于15—17℃和29—32。Cohort Ⅲ基本不出现于水温大于24℃的站位,其丰度与水温呈显著负相关。Cohort Ⅰ基本不出现于水温低于11℃的站位,其丰度与水温呈显著正相关。Cohort Ⅱ高丰度区的表层水温和盐度为26—27℃和30—32。由上推测强壮滨箭虫发生明显体型更替的水温阈值应不超过15—17℃。
Aidanosagitta crassa （Tokioka, 1938） is the only dominant chaetognatha species in Laizhou Bay, Bohai Sea. This gelatinous species plays an important role in the ecosystem of Laizhou Bay, acting as the major carnivorous predator of small invertebrate and fish larva. In addition, it has different morphs responding to variations in environmental factors. To determine the population structure in Laizhou Bay, the detailed body size and abundance of A. crassa were analyzed monthly from 147 vertical net samples collected from May 2011 to April 2012 （excluding December 2011 and January and February 2012, because of the presence of sea ice）. Results showed that A. crassa occurred continuously and was distributed extensively throughout the survey seasons and area in the bay. Both the abundance and biomass of the species presented twopeaks, a considerable peak in May, and a second peak during August to September. Individuals with a body length of about 4 and 15 mm were the major contributors to the total abundance and biomass, respectively. The production of the A. crassa population was estimated to be 0.25 mg C m 3 d-1, whereas the feeding rate was 0.88 mg C m 3 d-~ during the survey months. The body size of A. crassa fluctuated seasonally, with the largest sizes in March and April （mean body length 〉 10 ram） , and the smallest in May and November （mean body length 〈 5 mm）. The mean body length of the species showed an inverse correlation with both surface water temperature （SWT） and surface water salinity （SWS） of the corresponding period. Based on length-frequency distributions, different types of population pyramids occurred, namely, the expanding type in May to November except in June, stationary type in March to April, and constrictive type in June. The growing season for the A. crassa population in Laizhou Bay was presumed to be from May to August, because of the presence of abundant small individuals. Moreover, from the monthly length-frequency distributions, three common normalized cohorts （I, II, III） were detected with mean lengths of 〈 5, 5-10, and 〉 10 ram, respectively. Regarding their spatial distributions, individuals of cohorts III and I were the most abundant at sites with an SWT of 15-17℃ and SWS of 29-32 during spring. However, cohort III showed a considerable negative correlation between its abundance and water temperature, with a limited abundance at warm sites with an SWT 〉 24℃. Additionally, cohort I showed a positive correlation between its abundance and water temperature, and showed a limited abundance at cold sites with an SWT 〈 11 ℃. Cohort II was most abundant at sites with an SWT of 26-27℃ and SWS of 30-32 during autumn. From above the results, it was assumed that the water temperature threshold was lower than 15-17℃ for the transformation between the two typical size morphs, i.e., the large winter and small summer forms of A. crassa.
出处
《生态学报》
CAS
CSCD
北大核心
2017年第15期5189-5197,共9页
Acta Ecologica Sinica
基金
国家基金委-山东省联合基金项目(U1406403)
国家重点基础研究发展规划项目(2011CB403604)
公益性行业(农业)科研专项(201303050-01)
山东省自然科学基金(2009ZRB02317)
关键词
强壮滨箭虫
体长
丰度
生产力
季节分布
莱州湾
Aidanosagitta crassa
body length
abundance
production
seasonal distribution
Laizhou Bay
