Turnover of dead jellyfish: stimulation and retardation of microbial activity
Turnover of dead jellyfish: stimulation and retardation of microbial activity
复制标题
DOI：
10.3354/meps325043
复制
发表时间：
2006-11
影响因子：
2.5
通讯作者：
Josefin Titelman;L. Riemann;T. Sørnes;T. Nilsen;Petra Griekspoor;U. Båmstedt
中科院分区：
文献类型：
--
作者：
Josefin Titelman;L. Riemann;T. Sørnes;T. Nilsen;Petra Griekspoor;U. Båmstedt
关于水母种群数量崩溃后的命运，人们知之甚少。我们在挪威的Raunefjorden进行了一次远洋原位实验，测定了死亡的周叶罗非鱼的周转率。衰变是指数型的，衰变系数在0.67~1.12d-1之间；较小的水母翻过来的速度比较大的水母快。迅速的周转表明，在水母水华崩溃时，大量的碳和氮被转移到远洋和/或底栖食物网。在挪威Lurefjor-den的船上实验中，利用天然细菌组合，研究了细菌和死亡水母之间的相互作用。细菌在孵化过程中的生长和形态表明，只有某些形态类型的细菌在水母组织附近增殖。随后的实验证实，一些细菌可以利用水母作为底物，而另一些细菌则受到抑制。对敏感菌株的试验表明，对细菌生长的抑制取决于身体部位、大小和使用的周叶拟青霉的浓度。由于只有一些细菌能够利用周叶拟青霉作为底物，我们认为死亡的水母在特定的浮游食物网中作为营养纽带的作用部分取决于细菌群落组成。
Little is known about the fate of jellyfish biomass after their populations crash. We mea- sured turnover rates of dead Periphylla periphylla in a pelagic in situ experiment in Raunefjorden, Norway. Decay was exponential, with decay-coefficients of 0.67 to 1.12 d -1 ; smaller jellyfish turned over faster than larger ones. The rapid turnover suggests that large amounts of carbon and nitrogen are transferred to the pelagic and/or benthic foodwebs at the collapse of jellyfish blooms. The inter- actions between bacteria and dead jellyfish were examined in a shipboard experiment in Lurefjor- den, Norway, using natural bacterial assemblages. Growth and morphology of the bacteria in the incubations suggested that only certain morphotypes proliferated in the vicinity of jellyfish tissue. Subsequent experiments with homogenized P. periphylla tissue and bacterial isolates from various phylogenetic groups confirmed that some bacteria could use jellyfish as substrate, while others were inhibited. Tests with sensitive isolates revealed that inhibition of bacterial growth depended on the body part, size and concentration of P. periphylla used. Because only some bacteria were able to use P. periphylla as a substrate, we suggest that the role of dead jellyfish as trophic links in specific pelagic foodwebs depends partly on bacterial community composition.