Meeting Abstract
Morphological studies of sea anemones (Cnidaria: Actiniaria) combine complementary techniques: gross dissections provide information on internal features in three dimensions and with low resolution whereas histology provides resolution at the cellular level in two dimensions. The appeal of micro-computed tomography (micro-CT) is its potential to improve characterization of morphological features by combining qualities of both methods with comparable cost and avoiding some of their shortcomings (e.g. slowness, small volumes, artifacts). Given the paucity of morphological characters used in the taxonomy of Actiniaria and the difficulties of establishing primary homologies, micro-CT has the potential to advance our understating of evolutionary patterns and offer insights into details of traditionally used characters. We show that micro-CT efficiently delineated morphological features in sea anemones despite the need for chemical staining due to sea anemone’s low-density tissue. Satisfactory staining of all tissue types resulted in high-contrast images consistent between scanned specimens with fine details of external and internal anatomy readily observed in 2D micro-CT images and 3D volumetric renderings. Because phylogenetic signal can be evaluated only when the presence and variability of a morphological character has been reliably determined, we discuss the advantages and limitations of incorporating micro-CT data in taxonomic and evolutionary studies in the group. Furthermore, we explore the potential of using this technology in the study of comparative anatomy of polyps across the Class Anthozoa which has been hindered by challenges in implementing traditional histological methodologies.
