I. Phylum EchinodermataII. Class AsteroideaThe Water Vascular SystemThe EndoskeletonRegenerative PropertiesFeeding & DigestionReproductionComplete Metamorphosis: developmental transformationIV. Class Echinoidea: Sea Urchins & Sand DollarsV. Class Crinoidea: Sea Lilies & Feather StarsVI. Class Holothuroidea: (sea cucumbers)BIO SCI 100 1st Edition Lecture 13Outline of Last Lecture I. Phylum Arthropoda: Part IIII. Subphylum HexapodaIII. Insect FlightsIV. Stinging InsectsOutline of Current Lecture I. Phylum EchinodermataII. Class AsteroideaIII. Class Ophiuroidea; Brittle StarsIV. Class Echinoidea; Sea Urchins and Sand DollarsV. Class Crinoidea; Sea Lilies and Feather StarsVI. Class Holothuroidea; Sea CucumbersCurrent LectureI. Phylum Echinodermata- Means spiny skin.- Appeared during the mid-cambrian (approx 530 mya).- 7,000 species.- All marine.These notes represent a detailed interpretation of the professor’s lecture. GradeBuddy is best used as a supplement to your own notes, not as a substitute.- Developmental change in symmetry. Bilateral symmetry as juveniles. Radial symmetry as adults.II. Class AsteroideaThe Water Vascular System Water enters and exits system via a pore called the madreporiteon the dorsal side. Connects to a complex canal system throughout the sea star. The Pedicellariae Ampulla Tiny ‘pincer-like’pedicellariae. At the base of spineon the dorsal surface. Provide protection and keep body surface free of debris.Tube-footThe Tube Feet On the ventral side. Project from grooves bordered by moveable spines. Used in locomotion. Each tube-foot is connected to internal muscular sac; ampulla. Movement is accomplished by: Ampulla contracting and forcing water into the tube foot, causing it to expand. Contraction of longitudinal muscles causes the tube foot to contract. Tube feet can also create suction and an adhesive mucous that allows echinoderms to adhere to surfaces.The Endoskeleton Is made of small calcium carbonate plates beneath the epidermis.Regenerative Properties Sea stars and brittle stars have the ability to regenerate injured or lost arms. If a broken arm has at least part of central disc still intact, an entire new starfish can be regenerated!Feeding & Digestion Most are carnivorous feeding on molluscs, crustaceans, small fish. Sea star digestion: Mouth => 2-part stomach in central disc => intestines => anus Mouth on the ventral side; anus and madreporite on dorsal side.Reproduction Dioecious with external fertilization. Both sexes release gametes into the water. Larva havebilateral symmetry.Complete Metamorphosis: developmental transformation Transformation from bilateral larval form to radial adult form. Larva attaches to substrate via a stalk. Larval mouth & anus disappear and develops new adult parts. Complete internal reorganization.III. Class Ophiuroidea; Brittle Stars- Arms used in locomotion.- Lack pedicellariae.- Madreporite near mouth (ventral side), which has five moveable plates.IV. Class Echinoidea: Sea Urchins & Sand Dollars - Endodermal plates expanded into an internal shell-like skeleton.- Spines are elongated for locomotion; also use tube-feet.Sea Urchin Digestion: - Mouth =>esophagus => Stomach =>intestines => anusSea Urchin Anatomy: Anus MadreporiteStomach-IntestineGonad MouthV. Class Crinoidea: Sea Lilies & Feather Stars- Mostlydeep water marine forms.- Many are sedentary.- Arms are flexible with 'feathery' branches that collect food.- Filter feeders.- Transport food down to the mouth, at the center.- Lack spines and pedicellariae.VI. Class Holothuroidea: (sea cucumbers) Endoskeletal plates extremely reduced, animals are soft-bodied. Tube-feet are well-developed; crawl along substrate. Tentacles surround mouth, involved in feeding; mostly scavengers. Respiratory tree: Tubes with many branches, is a specialized respiratory structure. Sometimes occupied with commensal symbiotic organisms, like polychaetes.Responses to predators: Auto-evisceration: when threatened or stressed, can expel all organs to distract predators, and regenerate them later. Some species expel Cuvierian tubules: sticky tentacles to entangle