Phylum Echinodermata Deuterostomia Anus forms from or near blastopore Mouth forms secondarily Fig. 22.CO

Protostomes vs Deuterostomes

Plutei Fig. 22.9

Echinoderm Development Metamorphosis of bilaterally symmetric larvae to pentaradial adults Fig. 22.8

Deuterostome Phylogeny

Fig. 22.28 Echinoderm Phylogeny

Echinoderm Symmetry Primary bilateral symmetry Larval forms Some adult forms Secondary pentaradial symmetry 5 radial divisions of major organ systems Fig. 22.2a

Phylum Echinodermata Spiny skin Endoskeleton Dermal ossicles CaCO3, Ca2(PO3)2

Pedicellaria Fig. 22.4

Phylum Echinodermata Water vascular system

Water Vascular System & Tube Feet Fig. 22.2b

Tube Feet

Hemal Canals Fig. 22.6

Class Asteroidea Central body disc Most frequently 5 arms Regeneration Starfish & Sea Stars

Asteroidea Anatomy

Asteroidea Anatomy

Regenerating Arms Fig. 22.7

Commensals of Echinoderms

Class Ophiuroidea Sea baskets Brittle Stars Reduced central disc Reduced tube feet Fig. 22.10b

Class Ophiuroidea Sea baskets Fig. 22.10b Basket stars

Ophiuroidea Anatomy Fig. 22.11

Ophiuroidea Anatomy Fig. 22.12

Class Echinoidea Sea urchins Fig. 22.17 Sea biscuits Sand dollars

Echinoid Anatomy Fig. 22.18

Echinoid Mouth – Aristotle’s Lantern Fig. 22.19

Class Holothuroidea Sea Cucumbers

Holothuroidea Anatomy Fig. 22.Fig. 22a

Holothuroidea Defense Reaction Eversion of the respiratory tree and lower intestine Some species produce toxins Fig. 22.23c

Class Crinoidea Feather Stars Sea Lillies Sessile Crinoids Fig. 22.25 Feather Stars Sea Lillies Sessile Crinoids Swimming Crinoid

Crinoid Anatomy Fig. 22.24