Starfish

1 Acknowledgement: Nearly all materials in these three Animal Diversity labs are adapted from Seattle Community College Bio 212 online lab material. Animal Diversity Three IX Phylum Echinodermata The approximately 7,000 species of echinoderms are spiny skinned, slow moving or sessile marine animals that are voracious feeders. Adults have an unusual symmetry not found in any other animal. They have a pentamerous radial symmetry, meaning that the body is arranged into five (or multiples of five) repeating units radiating from a central area. However, their larval stages have bilateral symmetry which changes to pentamerous during development. Embryological development follows the typical deuterostome pattern.