Computer-based 3-dimensional reconstruction of major organ systems of a new aeolid nudibranch subspecies, Flabellina engeli lucianae, from Brazil (Gastropoda: Opisthobranchia)

Abstract

Obtaining accurate and comprehensive anatomical information from small opisthobranch specimens has been a major problem. Computer-based 3-dimensional reconstruction from serial histological slides applying AMIRA (TGS Graphics) software is shown to be an efficient and fully reproducible way to analyse tiny and complex organ systems in their true relative positions and proportions; this method is herein applied to nudibranchs for the first time. We used Flabellina engeli lucianae n. subsp., a small aeolid (up to 8 mm body preserved length) from subtropical southern Brazil, to illustrate all major organ systems including nervous systems, and discuss them comparatively. Flabellina engeli lucianae differs externally from congeners by having a translucent body with opaque white and iridescent blue spots, orange ceratal bands, and by the special branching of cerata forming distinct groups on common peduncles. External and internal differences from the apparently geographically and hydrographically separated Caribbean specimens of F. engeli engeli Marcus & Marcus, 1968 are discussed in detail. © The Author 2007. Published by Oxford University Press on behalf of The Malacological Society of London, all rights reserved.