echinoderms. phylum echindermata share common features with chordatesshare common features with...

Download Echinoderms. Phylum Echindermata Share common features with chordatesShare common features with chordates Radial CleavageRadial Cleavage Deuterostomes

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  • Echinoderms

  • Phylum EchindermataShare common features with chordatesRadial CleavageDeuterostomes (Blastopore becomes anus)Development of true coeloemUsually slow moving or sessileUsually are radially symmetricalBody parts usually radiate from center (frequently as 5 spokes)Possess a thick calcium plate endoskeleton surrounded by a thin skin layerPossess a unique Water Vascular System, which continues throughout animal and extends into extensions called Tube Feet.Functions for locomotion, feeding, & gas exchange.Reproduce sexually or through regeneration.

  • Class AsteroideaInclude sea starsUsually have 5 (or multiple of 5) arms radiating from central diskTube feet located underneath each arm used for locomotion & grasping prey. Operate by hydraulic principles.

  • Anatomy of a Sea Star

  • FeedingFeed on mollusks by pulling shells apart and extending stomach outside the mouth into the bivalve. The bivalve is digested within it's shell. The sea star than re-ingests its stomach

  • ReproductionCan reproduce sexually by releasing sperm and egg.Can reproduce by regeneration

  • Sea Stars

  • Class Ophiuroidea Include Brittle StarsDistinct central disks with long tube-like armsLack suckersMove by serpentine motion of their arms

  • Brittle Star

  • Class EchinoideaInclude Sea urchins & sand dollarsLack arms, but possess tube feetMany species of urchins possess poisonous spines used for defense

  • EchinoideansSand DollarSea Urchin

  • Class HolothuroideaInclude Sea cucumbersAre elongated along oral-anal axisLack spines and have reduced endoskeleton.Do possess tube feet and water vascular system

  • Sea Cucumber

  • Class CrinoidiaAncient class of animalsInclude sea liliesFilter feeders with arms radiating from mouthMost are sessile, but some can move

  • Crinoids