Analysis of the shapes of coelomocytes of Aphelasterias japonica in vitro (Echinodermata: Asteroidea).

A description and formal classification of in vitro spreading coelomocytes from the Aphelasterias japonica sea star was performed using 39 parameters of linear and nonlinear morphometry based on the correlation, factor, and cluster analysis. The comparison of a variety of clustering models revealed the optimum classification parameters and algorithms. As a result, four morphological types of spreading cells significantly differing in a number of structural parameters were identified. This approach may be an important alternative or addition to classical methods of classification of polymorphic, irregularly shaped cells, in particular, cell elements of the invertebrate immune system. It provides the optimum methodology for structural analysis and classification of cells as a part of their further investigation in terms of structure, function, ontogeny, and diversity.