摘要
度夏过程对黄东海中华哲水蚤其种群延续具有重要的意义。通过2011年08月黄东海现场调查航次研究了中华哲水蚤夏季种群的分布和脂类含量,探讨了中华哲水蚤度夏期间的能量利用策略。结果表明,夏季在黄海中部以及浙江近岸存在中华哲水蚤的密集分布区域。其中,黄海冷水团内的中华哲水蚤以C5期(平均为77.4%)个体为主,而冷水团周边及浙江近岸站位则主要由C5期(分别为32.3%和33.2%)和雌体(分别为41.3%和51.8%)组成。脂类含量结果显示,冷水团内的C5期中华哲水蚤的总脂含量最高(平均43.1μg/个),浙江近岸雌体的总脂含量(平均24.6μg/个)和黄海冷水团周边雌体的总脂含量(平均18.2μg/个)较低。在完全饥饿的假设下,冷水团内的C5期中华哲水蚤具有明显的代谢优势,其储存的脂类可以维持超过18天的代谢需求。而在浙江近岸以及冷水团周边,中华哲水蚤储存的脂类则只可维持3—6d的需求。由此推测,黄海冷水团内的C5期中华哲水蚤依靠储存的油脂和较低的摄食率度夏,而冷水团以外的种群则需要在适宜温度下积极摄食才能顺利度夏。
Calanus sinicus is an ecologically important copepod species found in the shelf waters of the western part of the North Pacific Ocean. Over-summering strategies are important for the population dynamics of C. sinicus. In this paper, we studied the lipid content as well as the abundance and structure of the C. sinicus population in the southern Yellow Sea and East China Sea in summer to enhance our understating of the various over-summering strategies. In August 2011, C. sinicus was collected using a 500 μm mesh ring net （mouth opening, 0.5 m^2）. The samples used for studying the abundance and structure of the population were preserved in 5% formalin seawater solutions. The total lipid content was extracted from fifth copepodite （C5） or female C. sinicus with 3 mL chloroform ： methanol （ 2：1 v/v） at -20℃ for 16 h and weighted on a Cahn electrobalance （ ± 100 μg）. The lipid content was separated using a chromatographic method and analyzed in duplicate using Iatroscan MKS-6 with flame ionization detector （FID）. The results showed that certain regions in the Yellow Sea Cold Bottom Waters （YSCBW, water temperature〈 10℃） had the highest amount of C. sinicus ranging from 93.3 ind/m^3 to 446.9 ind/m^3（ mean, 242.6 ind/m^3）. The area near the shore of the East China Sea also showed an abundant C. sinicus population （range, 60.8--148.4 ind/m^3 ; mean, 91.0 ind/m^3）. In addition, regional differences were observed with regard to the structure of the population. In the southern Yellow Sea, C5 accounted for 77.4% of the total population in the YSCBW, while C5 and females contributed to 32.3% and 51.8%, respectively, out of the YSCBW. In the East China Sea, the structure of the population was similar to that outside the YSCBW with 33.2% of C5 and 41.3% females. The results of the abundance and structure of the population indicate that the area near the shore of the East China Sea may also act as a preservation area for C. sinicus in summer along with the YSCBW. The total lipid content in female C. sinicus was approximately 5.4--17.2% of their dry body mass, while C5 had higher lipid content （22.4%--40.1%）. The lipid content of C5 in the YSCBW was 43.1 μg/ind, while the lipid content of the females in the YSCBW （mean, 24.6 μg/ind） and at the area near the shore of the East China Sea （mean, 18.2 μg/ind） was lower than C5 in YSCBW. The major lipid classes were wax ester and phospholipid and together they comprise of approximately 90% to the total lipid content. The C5 in the YSCBW can survive longer （ 18 days） than C.sinicus in other areas （≤6 days） by utilizing the lipid content as their sole energy source for their basic metabolic needs. However, this is still insufficient for successful over-summering of C.sinicus. The C5 in the YSCBW can use stored lipid and sustain on a limited food supply during over-summering, while C. sinicus in other areas require active feeding to survive during the summer.
出处
《生态学报》
CAS
CSCD
北大核心
2014年第16期4632-4639,共8页
Acta Ecologica Sinica
基金
国家自然科学基金(41076099,41121064)
国家重点基础研究发展规划(973)项目(2011CB403604)
关键词
中华哲水蚤
脂类
度夏
能量利用
Calanus sinicus
lipid
over-summering
energy-consumption
