Transcript Zoology
Zoology Phylum Echinodermata I. Intro to Echinoderms A. Name means “sharp spines” B. Radial symmetry 1. able to cut in half equally 2. Usually 5 segments -can be more C. Regeneration 1. Ability to grow back D. Pedicellariae – tiny spines E. Mainly marine F. Bottom dwellers II. Class Holothuroidea A. Facts 1. Common Ex: a. Sea cucumber 2. Shaped like vegetable 3. Deep ocean dwellers a. Philippine Trench (10540 m) 4. Bottom Grazers B. Special Anatomy of Sea Cucumber 1. Mouth a. 10-30 tentacles 2. Body a. 5 rows of tube feet b. Respiratory Tree (lung) c. Some contain toxins III. Class Crinoidea A. Facts 1. Ex: sea lilies, feather stars 2. Body calyx a. Tegmen – leathery skin; contains calcareous plates 3. Calyx + arms crown 4. Mostly sessile 5. Separate sexes (males and females) 6. Tentacles some poisonous IV. Class Asteroidea A. Facts 1. Ex: sea stars + starfish 2. found along shorelines + rocky areas 3. Brightly colored 4. Found world wide B. External Anatomy (Ventral Side) 1. Central Disc – circular center of starfish 2. Arms – usually 5 3. Mouth – ventral side – central disc 4. Ambulacral Groove – runs lengthwise of arm toward the mouth 5. Tube Feet – found inside ambulacral groove 6. Spines – cover starfish 1. Central Disc 3. Mouth 2. Ambulacral Groove 6. Tube Feet 4 + 5. Arm/Spines C. External Anatomy (Dorsal Side) 1. Madreporite – Water intake valve 2. Anus – removes waste -inconspicuous 3. Pedicellarie – tiny jaws around base of spine -used to keep surface free -protection -aid in catching food 4. Eyespot -senses motion (black/white) -found at end of arm Madreporite D. Internal Anatomy 1. Canals (Locomotion) – connected to madreporite a. Stone Canal – transfers water from madreporite to ring canal b. Ring Canal – transfers water to radial canal c. Radial Canal – transfers water to lateral canal d. Lateral Canal – transfers water to tube feet e. Ampulla – muscular sac that pushes water out causing locomotion Madreporite Stone Canal Tube Feet /Ampulla Ring Canal Radial Canal Lateral Canal 2. Digestive System a. Stomach -Cardiac – ventral *can be everted (pushed out) -Pyloric – dorsal *completes digestion b. Intestine…anus c. Feed on… -clams, oysters, mussels, fish *How do they get inside of a clam?* 3. Nervous System a. Nerve Plexus – acts as brain b. Nerve ring – runs around the central disc c. Radial nerve – runs to each arm d. Sensitive to touch, light, chemicals, and temp 4. Reproductive System a. Separate Sexes b. External fertilization