June 10, 2009

Sea urchin internal structure cataloged

German scientists have cataloged the sea urchin axial complex, an internal structure with undetermined function.

The researchers at the Charite University of Medicine in Berlin said the research shows within that group of marine invertebrates there exists a structural evolutionary interdependence of various internal organs. The finding, the scientists said, demonstrates the approach of combining all structural data available on a given organ in combination with a broad taxonomic coverage can yield novel insights into the evolution of internal organ systems.

Led by Alexander Ziegler, the scientists used magnetic resonance imaging to compare the structure of the axial complex of specimens from nearly all sea urchin (Echinoidea) orders. Those data were supplemented with invasive techniques such as dissection, histology and transmission electron microscopy.

This kind of study is very powerful in elucidating interdependent anatomical relationships that are not obvious when the analysis is carried out only with a few species, Ziegler and his colleagues said. This should limit the confusion caused by the bewildering range of terminology applied by different authors and in different languages to the same anatomical entities.

The study appears in the journal Frontiers in Zoology.