Phototaxis of sacoglossan sea slugs with different photosynthetic abilities: a test of the ‘crawling leaves’ hypothesis.
Phototaxis of sacoglossan sea slugs with different photosynthetic abilities: a test of the ‘crawling leaves’ hypothesis.
复制标题
具有不同光合能力的 sacoglossan 海蛞蝓的趋光性：“爬行叶子”假说的检验。
DOI：
10.1007/s00227-015-2673-1
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发表时间：
2015
期刊：
影响因子：
2.4
通讯作者：
Yusa Y
中科院分区：
文献类型：
--
作者：
Miyamoto A;Sakai A;Nakano R;Yusa Y
几种囊舌海蛞蝓利用从藻类摄取的叶绿体进行光合作用（kleptoplasty），这是一种在其他动物中未知的独特营养策略。它的适应意义，特别是在这一现象中涉及的行为适应，尚未得到充分探讨。为了解决这个问题，kleptoplasty对趋光性的影响进行了调查，跨物种和物种内，使用sacoglossans收集沿着日本海岸在2012年和2013年。首先，使用具有光梯度（4-330 μmol光子m−2s−1）的I-迷宫研究了具有不同光合能力的五种sacoglossans的趋光性和偏好光强度的存在。每个个体移动30 min以选择最佳光照强度。trisinuata和Plakobranchus ocellatus都具有较高的光合活性（即kleptoplastic），表现出正的趋光性。其中，E. hamatani对光照强度的适应性最强，其次是P. ocellatusandE. trisinuata，其顺序与其栖息地的浅度相对应。相反，Stiliger ornatus和Placidasp.，几乎没有光合活性（非kleptoplastic），分别显示中性和负趋光性。 其次，研究了E.比较了具有（进食）和不具有（饥饿）功能性叶绿体的hamatanii个体，以检查存在的kleptoplasts对物种内趋光性的影响。饥饿和饥饿的个体均表现出正趋光性，但饥饿个体的趋光性低于饥饿个体。这些结果表明，具有功能性叶绿体的sacoglossans表现出积极的趋光性朝向一个优选的光强度，这可能有利于光合作用效率。
Several sacoglossan sea slugs utilise chloroplasts ingested from algae for photosynthesis (kleptoplasty), a unique trophic strategy unknown in other animals. Its adaptive significance, especially the behavioural adaptations involved in this phenomenon, has not been fully explored. To address this issue, the effects of kleptoplasty on phototaxis were investigated, both across and within species, using sacoglossans collected along Japanese coasts in 2012 and 2013. First, the presence of phototaxis and preferred light intensity was studied in five sacoglossans with various photosynthetic capabilities using an I-maze with a light gradient (4–330 μmol photons m−2s−1). Each individual was allowed to move for 30 min to choose the optimal light intensity.Elysia hamatanii,E. trisinuata, andPlakobranchus ocellatus, all with high photosynthetic activity (i.e. kleptoplastic), showed positive phototaxis. Among them,E. hamataniipreferred the highest light intensity followed byP. ocellatusandE. trisinuata, and the order corresponded with the shallowness of their habitats. Conversely,Stiliger ornatusandPlacidasp., with virtually no photosynthetic activity (non-kleptoplastic), showed neutral and negative phototaxis, respectively. Next, the phototaxis ofE. hamataniiindividuals with (fed) and without (starved) functional chloroplasts was compared to examine the effects of the presence of kleptoplasts on phototaxis within a species. Both fed and starved individuals showed positive phototaxis, but the preferred light intensity of starved individuals was lower than that of fed individuals. These results suggest that sacoglossans with functional chloroplasts exhibit positive phototaxis towards a preferred light intensity which may benefit photosynthesis efficiency.