Variation or species in aeolid nudibranchs

从形态和分子水平上分析了一些风化裸肢动物种群中发现的“变异”现象，发现四面藻的两个颜色形态是两个独立的种。它们拥有截然不同的。在保存下来的标本中很难发现这种差异，这应该是为什么它们被认为是单一物种的变异的原因。两个学名相同的樱花属相似种被恰当地用不同的名称来描述。活体标本可以很容易地通过包括颜色图案在内的一些外部特征进行识别，而当保存下来时，这些特征变得模糊，不再用于区分两者。本文还对日本新记录的非典型衣藻的颜色变化进行了研究。除颜色和大小外，在外部形态上没有发现差异，内部形态上也没有差异，这强烈表明它是单一物种的变异。这也得到了COI区线粒体DNA的比较。随着这些研究在这一助学金的帮助下完成，我们发现活着的外部形态提供了比我们过去期望的更多的物种鉴定信息。这将鼓励通过照片和出版数据库来鉴定物种。众所周知，一种分布广泛的带有虫黄藻的凤尾草在不同地区的颜色是不同的。这种变异目前正在从生态学的角度进行调查。

"Variations" found in the population of some aeolid nudibranchs were examined morphologically, and also molecularly when necessary.Two color morphs of Facelinella quadrilineata were found to be two separate species. They possess very different penes. The difference is not easily detectable in preserved specimens, and this should be the reason why they had been considered to be variations of a single species. This study also proved that the genus Facelinella was invalid.Two similar species of the genus Sakuraeolis, which had been given a same scientific name, were properly described with suitable different names. Alive specimens of the two aeolids were easily identified by a few external characters including color pattern, while when preserved such characters become obscure and no longer useful to distinguish the two. The radular morphology was found to be the only character to distinguish them in preserved condition.Color variation of Chlamylla atypica, an aeolid newly recorded from Japan was also examined. For this aeolid no difference was found in external morphology except for color and size, nor in internal morphology, which strongly suggested that it was to be variation of a single species. This was also supported by comparison of mitochondorial DNA of COI region.With these studies completed with help of this grant-in-aid, it is revealed external morphology in alive condition provides much more information than we used to expect for species identification. This will encourages identification of species by photographs and publishing databases.A widely distributed aeolid with zooxanthellae, Pteraeolidia ianthina, is known to be differ in color among localities. This variation is now under investigation in the light of ecology.