Flashcards and possible test questions for Introduction to Marine Phyla

1. They are bell-shaped/tubular animals 2. Their body has layers: - Outer protective epidermis - Mesoglea - Gastrodermis - Inner endoderm layer – secretes juices and enzymes directly into gastrovascular cavity (GVC). 3. They possess radial symmetry 4. Their mouth is surrounded by tentacles connected to GVC. 5. They have no circulatory, respiratory, or excretory organs. 6. Reproduction has two phases = sexual budding (polyps) and sexual reproduction (medusa). 7. All are aquatic – mostly marine species. 8. They have 2 basic body forms during their life cycle: - Polyps – mouth directed upwards, tubular/flower-like, sessile. - Medusa – mouth directed downwards, jellyfish/umbrella shape, mobile. 9. Muscle fibres & nerve fibres can contract and expand which results in directional movement. 10. Polyps are sessile (stay in one place) = e.g. sea anemones 11. Medusas are mobile (float or swim in a water column) = e.g. jellyfish 12. Tentacles form a ring around the mouth & can reach out and grasp prey that has been stung by cnidocytes. 13. Gaseous exchange occurs directly across the body surface. 14. Waste is released either through gastrovascular cavity (GVC) or through the skin.

1. Littoral zone - this is the uppermost area of the shore. It receives the most exposure to the sun and the least exposure to the water. Species examples include: Littorina sp., Natal Rock Oyster, Natal Mussel, and Zooanthid polyps. 2. Oyster belt - this zone occurs only on the east and south coasts. This area is similar to the littoral zone but with a high density of oyster species. Other species examples include whelks, and Grapsus crabs. 3. Upper Balanoid Zone - This area is only exposed to the air during low tide, so the species present are less resistant to heat and desiccation than those in the littoral zone. This zone is dominated by barnicles, with other species including limpets, tubeworms, and algal moss. 4. Lower Balanoid Zone - this area is where most wave action occurs. Species are much less tolerant of air, and are adapted to life in the waves. Species include kelp, mussels, sea urchins, and sponges. 5. Infratidal Zone - this is the zone where the rocky shore begins to change into the ocean floor. There is no air exposure here. Species include corals and corallines, algae, and red bait.