BIOL 371 Lecture Notes - Lecture 8: Ctenophora, Cnidaria, Symmetry In Biology
Document Summary
Hexacorallia- stony corals that sit inside caco3 cups that they make. Colonial and share a gastrovascular cavity and connected by interconnecting tubes called solonia. Covered with an epidermis that has spicules in it which forms an exoskeleton which comes in a variety of shapes. Made up of both the hexacorals and octocorals, but the hexacorals with the caco3 cups are main ones for the structure. 30 degrees n latitude and 30 degrees s latitude. Need seawater salinity so can"t be near river deltas. Recycle phosphorous and nitrogen and to assist in caco3 deposition. When the zooxanthellae die, the reef becomes brittle. Caused by damages to the zooxanthellae because of warmer waters which produces oxidants that cause the coral to expel them in an immune response (bleached coral) Unlike cnidarian jellyfish, they have no nematocysts and swim using rows of cilia. Capture food as they swim and can use tentacles. Digestion and nervous system is similar to cnidarians.
