Marine Ecology, April 30, 2008Invertebrates 4: Phylum Echinodermata & Phylum Chordata!

Phylum EchinodermataBasic features Calcareous internal

skeleton Water vascular

system (controls tube feet)

Pentamerous symmetry (adults)/bilateral symmetry (larvae)

Mutable connective tissue

General body organization

Class Asteroidea (sea stars)

Appearance Location Other aspects of natural history

Pycnopodia helianthoidesPisaster ochraceus

Class Echinoidea (urchins and relatives) Appearance Location Other aspects of natural history

Strongylocentrotus purpuratus

Strongylocentrotus franciscanus

Class Holothuroidea(sea cucumbers) Cucumaria miniata

Photo: Neil McDaniel, Waterhouse Marine Images

Class Ophioroidea(Brittle stars, basket stars)

Class Crinoidea(Sea lilies, a.k.a feather stars)

Phylum ChordataSubphylum Urochordata

Our closest invertebrate relatives are slimy sacs that pump seawater

Class Ascidacea (tunicates)

Family Cottidae: sculpins

Family Gobiesocidae: clingfish

Family Pholidae: gunnels

Photo: Pelagia Scuba

Family Hexagrammidae (lingcods and greenlings)