2000 Fiscal Year Final Research Report Summary
Variation or species in aeolid nudibranchs
| Project/Area Number |
09640823
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
系統・分類
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| Research Institution | Chiba University |
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Principal Investigator |
HIRANO Yoshiaki Marine Biosystems Research Center, Research Assistant Professor, 海洋バイオシステム研究センター, 助手 (00144808)
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| Project Period (FY) |
1997 – 2000
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| Keywords | Aeolid nudibranch / variation or species / morphology / molecular / reproductive isolation |
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| Research Abstract |
"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.
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