Marine Invertebrates (Part 3) Phylogenetics Protostomes (mouth first) Deuterostomes (mouth second) Embryo cell division simple complex Lophophorates Common feeding structure lophophore (ciliated tentacles in rounded shape) Three phyla: Phoronida (worm-like) Brachiopoda (clam-like) Bryozoa/Ectoprocta (coral-like) Bryozoanszooids Bryozoans Arrow Worms Phylum Chaetognatha only marine few species but abundant important predators Echinoderms Phylum Echinodermata (spiny skinned) All are marine Larvae have bilateral symmetry, but adults have 5-way radial symmetry NOAA Echinoderms Distinctive features: water vascular system and tube feet (hydraulic) Echinoderms Five classes: Asteroidea - Sea stars (starfish) Ophiuroidea - Brittle stars Echinoidea - Sea urchins Holothuroidea - Sea cucumbers Crinoidea - Crinoids (sea lilies, feather stars) Sea Stars Sea Stars NOAA Brittle Stars Sea Urchinstest.jpg Sea Urchins Sea Cucumbers NOAA Crinoids NOAANOAA Deep-Sea Echinoderms NOAA Hemichordates Missing link between echinoderms and chordates Acorn worms ProtostomesDeuterostomes Embryo cell division Hemichordates 2 common features with chordates Invertebrate Chordates Phylum Chordata Subphylum Urochordata Tunicates, salps, larvaceans Subphylum Cephalochordata Lancelets Subphylum Vertebrata Fishes, amphibians Reptiles, birds Mammals Invertebrate Chordates Common features of all chordates: Dorsal (back) hollow nerve cord Notochord (flexible support rod, becomes backbone in vertebrates) Gill slits in the pharynx Post-anal tail Ventral heart Human embryo days Tunicates (Sea Squirts) Phylum Chordata Subphylum Urochordata Have all chordate features as larva, lose most as adults Benthic as adults Tunicates (Sea Squirts) Salps, Larvaceans Phylum Chordata Subphylum Urochordata Keep some/all chordate features as adults Planktonic NOAA Lancelets Phylum Chordata Subphylum Cephalochordata Have all chordate features as adults, just lack backbone Benthic * * * typo in 7 th ed book (correct info here) Level of organization Symmetry CellularNone TissueRadial TissueBi-radial Organ systemBilateral Organ systemBilateral Organ systemBilateral Organ systemBilateral Organ systemBilateral Organ systemBilateral Organ systemRadial (as adult) Organ systemBilateral Organ systemBilateral