Mineralogical and biological study on the bryozoan Calyptotheca alexandriensis collected from Alexandria, Egypt

Abstract

Calyptotheca alexandriensis, has been recently recorded at the Eastern Harbour of Alexandria, Egypt, and described as a new bryozoan species. This study focuses on the mineralogical structure of the calcareous shell of C. alexandriensis and the morphological features of its polypides using XRD, SEM and EDS. The results revealed that the shell of C. alexandriensis contains aragonite in dendritic crystal habit and calcite in the rhombohedral structure. These findings were confirmed by the presence of some aragonite-related cations such as Ba and Pb and other calcite-related cations as Mg. The autozooid polypides have an elongated cylindrical body with a lophophore of 14-16 tentacles.