Invertebrates Octopus Video

Phylum Echinodermata 1.Asteroidea (Sea Stars) – Keystone Species

Phylum Echinodermata 2.Ophiuroidea (Brittle Stars, Serpent Stars)

Phylum Echinodermata 3.Echinoidea (Sea Urchins, Sand Dollars, Sea Biscuts) Endoskeleton has a round, rigid test Moveable spines and pedicellarie Have 5 rows of ambulacral grooves Herbivores – eat attached or drifting seaweed and seagrasses

Phylum Echinodermata 3.Echinoidea (Sea Urchins, Sand Dollars, Sea Biscuts)

Phylum Echinodermata 4.Holothuroidea (Sea Cucumbers) Lack spines and obvious radial symmetry Endoskeleton reduced to small spicules in skin Have a respiratory tree Deposit and filter feeders Evisceration

Phylum Echinodermata 4.Holothuroidea (Sea Cucumbers)

Phylum Echinodermata 4.Holothuroidea (Sea Cucumbers) Enypniastes eximia

Phylum Echinodermata 5.Crinoidea (Sea Feathers and Lilies) Suspension feeders Capture food with tube feet and mucus Ciliated ambulacral grooves mood food to mouth Video Clip Video Clip

Phylum Echinodermata 5.Crinoidea (Sea Feathers and Lilies) Feather stars – Unstalked Cosmopolitan, but especially abundant in warm water Capable of swimming Sea lilies – Stalked Uncommon, restricted to deep water

Phylum Hemichordata

Hemichordates Mainly Acorn Worms Deposit feeders Live in U-shaped burrow – process lots of sediment Get organic matter from mucus secreting proboscis

Phylum Hemichordata Hemichordates Mainly Acorn Worms Deposit feeders Live in U-shaped burrow – process lots of sediment Get organic matter from mucus secreting proboscis

Phylum Chordata

Four Major Characteristics Three Subphyla 1.Urochordata – Tunicates 2.Cephalochordata – Lancelets 3.Vertebrata – Vertebrates

Phylum Chordata 1.Urochordata - Tunicates A.Ascidiacea (Class) – Sea squirts Only sessile chordates Body covered by tunic (gelatinous outer covering) Active suspension feeders (filter feeders) Water pumped in through incurrent siphon and out through excurrent siphon Particles filtered out by feeding basket (pharynx) Planktonic tadpole larva Possesses all four chordate characteristics Doesn’t feed – resorbs notochord and tail at settlement

Phylum Chordata

1.Urochordata - Tunicates B.Thaliacea – Salps Planktonic Transparent body with radial bands of muscle for locomotion Solitary or colonial

Phylum Chordata 1.Urochordata - Tunicates C.Larvacea – Appendicularians Planktonic Superficially similar to tadpole larva Secrete mucus “house” for protection and feeding Feeding Link

Phylum Chordata B.Cephalocordata - Lancelets Possess all chordate characteristics throughout life (no backbone) Inhabit soft bottoms Suspension feeders (filter feeders) Gill slits used to filter particles out of water

Fig 7.49 Female Male

Phylum Chordata C. Vertebrata Share four chordate characteristics + vertebral column (spine, backbone) Spine encloses and protects nerve cord (spinal cord) Anterior end of spinal cord = brain protected by skull made of bone or cartilage 1. Fishes Oldest group of vertebrates (530 mya ) 27,000+ species (15,600+ marine spp.) Three major groups