New life-cycle stages of Gymnodinium catenatum (Dinophyceae):: laboratory and field observations
New life-cycle stages of Gymnodinium catenatum (Dinophyceae):: laboratory and field observations
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DOI：
10.3354/ame01206
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发表时间：
2008-01-01
影响因子：
1.4
通讯作者：
Morono, Angeles
中科院分区：
文献类型：
--
作者：
Figueroa, Rosa Isabel;Bravo, Isabel;Morono, Angeles
链形成的甲藻Gymatriinium catenatum负责麻痹性贝类中毒（PSP）的爆发，然而，在这个物种的水华出现的底栖生物-浮游生物的生命周期转换的相对重要性需要澄清。本研究首次通过田间试验和室内试验相结合的方法，分析了银杏开花过程中营养细胞和有性阶段的动态变化。链状结构在天然样品中，G. catenatum与几种不同的细胞行为和形态有关。这证实了实验室证据的物种的性过程的可逆性和受精卵的能力，无论是旁路或缩短路径休眠囊肿形成。此外，链多达4个可行的囊肿与不同的形态发生，这些从来没有报道过这个物种。至少有两个囊肿有网状表面，在以前的研究中与有性生殖有关的功能;这一观察结果表明，性过程参与的机制，不能解释任何已知的生命周期路线描绘这个物种。花盛期的形态变异性和有性阶段的丰富性表明了花盛期的复杂性。catenatum的性周期以及有性生殖在该物种生态演替中的重要作用。然而，在性休眠期缺乏休眠期（证明了大量的萌发孢囊在沉积物中采样开花后3个月）表明，近海种群的平流向岸边，而不是“种子床”，是主要的机制解释G。catenatum开花形成在加利西亚rias。
The chain-forming dinoflagellate Gymnodinium catenatum is responsible for outbreaks of paralytic shellfish poisoning (PSP); however, the relative importance of benthic-planktonic life-cycle transitions in the appearance of blooms of this species needs to be clarified. By coupling field and laboratory experiments, the present study is the first to analyze the dynamics of vegetative cells and sexual stages during a bloom of G. catenatum. In natural samples, the sexual stages of G. catenatum were associated with several different cellular behaviors and morphologies. This confirmed laboratory evidence for the reversibility of the species' sexual processes and for the ability of zygotes to either bypass or shorten the route to resting-cyst formation. Moreover, chains of up to 4 viable cysts with differing morphologies occurred and these have never been reported previously for this species. At least two of the cysts had reticulated surfaces, a feature related to sexual reproduction in previous studies; this observations suggests the involvement of sexual processes in mechanisms that cannot be explained by any known life cycle route depicted for this species. Morphological variability and abundance of the sexual stages during the bloom indicated the complexity of the G. catenatum sexual cycle and the important role of sexual reproduction in the ecological succession of this species. However, the lack of a dormancy period in the sexual resting stage (evidenced by the large number of germinated cysts in sediments sampled 3 mo after the bloom) indicated that the advection of offshore populations shoreward, rather than 'seed beds', is the main mechanism explaining G. catenatum bloom formation in the Galician rias.