Marine Biology: Diversity MARE 171 Marine Biology: Diversity Dr. Turner Fall 2014

Lower Invertebrates Cnidarians digest their prey in a central Gastrovascular cavity: functions both in digestion and movement of materials; waste forced back through the mouth

Lower Invertebrates Reproduction: Hydrozoans j Reproduction: Hydrozoans Asexual (polyp) and Sexual (Medusa) stages Planular larvae: the planktonic larval stage of a cnidarian

Lower Invertebrates Reproduction: Scyphozoans j Reproduction: Scyphozoans Sexes generally separate; medusa sexual stage, produce planula larvae, form polyp, produce medusa-like buds by asexual reproduction

Lower Invertebrates Reproduction: Anthozoans - Asexual reproduction common Pedal Laceration: a type of asexual reproduction that occurs in sea anemones in which a portion of the animal’s base (Pedal Disk) is broken off and forms a new individual

Lower Invertebrates Reproduction: Anthozoans - Asexual reproduction common Fission: a type of asexual reproduction that occurs in sea anemones in which the anemone splits into two and each half develops into a new individual

Lower Invertebrates Ecological Roles of Anemones Predator-Prey Habitat Symbiosis

Lower Invertebrates Ctenophores (Comb Jellies): are gelatinous zooplankton belonging to the phylum Ctenophora - Nearly transparent; eight rows of comb plates (Ctenes): rows of cilia used by ctenophores for locomotion Statocyst: an organ found in some animals that helps them maintain equilibrium

Lower Invertebrates Ctenophores are carnivorous, feeding on zooplankton, larval fish, and fish eggs Colloblasts: are specialized adhesive cells found on the tentacles of some ctenophores and are used to capture prey Cydippid Larva: planktonic larva of a ctenophone

Lower Invertebrates Bilateral Symmetry: a type of body organization in which the body parts are arranged in such a way that only one plane through the midline of the central axis divides the animal into similar halves Midsaggital Plane: a plane through the midline of the central axis of an animal

Lower Invertebrates Flatworms (Phylum Platyhelminthes) - flattened Cephalization: the evolutionary process whereby sense organs became concentrated in the head of an animal