Middlebrooks Michael L, Curtis Nicholas E, Pierce Sidney K
Biol Bull. 2019 Apr;236(2):88-96. doi: 10.1086/701732. Epub 2019 Feb 13.
Sacoglossan sea slugs feed by suctorially consuming siphonaceous green algae. Most sacoglossan species are feeding specialists, but the Caribbean coral reef-dwelling Elysia crispata is polyphagous and sequesters chloroplasts from multiple algal species into cells lining its digestive diverticulum for use in photosynthesis. We have used sequences of the chloroplast-encoded rbcL gene to compare the chloroplast donor algae in five populations of E. crispata from various Caribbean locations. We found that E. crispata utilizes more algal species than was previously known, including some algae previously not reported as present in the region. In addition, slugs from each location had unique chloroplast arrays with little overlap, except that all locations had slugs feeding on algae within the genus Bryopsis. This variation in diet between locations suggests that the slugs may be exhibiting local adaptation in their dietary choices, and it highlights ecological differences between the Caribbean-wide reef-dwelling ecotypes and the mangrove lagoon ecotypes found in the Florida Keys.
囊舌类海蛞蝓通过吸食虹吸藻科绿藻来进食。大多数囊舌类物种是进食专家，但生活在加勒比珊瑚礁的波纹背海兔是杂食性的，它会将多种藻类的叶绿体隔离到其消化盲囊内衬的细胞中，用于光合作用。我们利用叶绿体编码的rbcL基因序列，比较了来自加勒比不同地点的五个波纹背海兔种群中的叶绿体供体藻类。我们发现，波纹背海兔利用的藻类物种比之前已知的更多，包括一些之前未被报道在该地区存在的藻类。此外，除了所有地点的海蛞蝓都以蕨藻属藻类为食外，每个地点的海蛞蝓都有独特的叶绿体组合，几乎没有重叠。不同地点之间饮食的这种差异表明，海蛞蝓在饮食选择上可能表现出局部适应性，这突出了整个加勒比地区珊瑚礁栖息生态型与佛罗里达群岛红树林泻湖生态型之间的生态差异。
