major animal phyla porifera, cnidaria, platyhelminthes, annelida, mollusca, arthropoda,...
TRANSCRIPT
Major Animal Phyla
Porifera, Cnidaria, Platyhelminthes, Annelida,
Mollusca, Arthropoda, Echinodermata, and Chordata
Phylum Poriferasponges
• Have no definite shape – asymmetrical;• No tissues or organs• Colony of specialized cells• Immobile• Good powers of regeneration• Skeleton of spongin and spicules
CLASSES OF SPONGES
• Class Calcarea – has calcium carbonate spicules
• Class Hexactinellida – glass sponges with spicules of silica
• Class Demospongiae – no spicules, only spongin
SPONGE ANATOMY
Barrel sponge
Tube sponge
Venus Flower Basket
Phylum Cnidariastinging-celled animals
• Jellyfishes, corals, anemones
• Radial symmetry
• Two tissue layers with inner mesoglea
• Primitive nerve net but no brain
• 2-way digestive tract
• Stinging cells for capturing food.
CLASSES OF CNIDARIANS
• Class Hydrozoa – Hydra, Portuguese-Man-of-War, Obelia; mostly polyp or hydroid stage
• Class Scyphozoa – true jellyfishes; mostly medusa stage
• Class Anthozoa – corals, anemones
• Class Cubozoa – box jellies
CLASS HYDROZOA
Hydra
CLASS SCYPHOZOA
Moon jelly
CLASS ANTHOZOA
Sea anemone
Aggregating anemones
Anemone
Coral polyps
CLASS CUBOZOA
Phylum Platyhelminthesflatworms
• First animals to exhibit bilateral symmetry
• Have primitive brain
• 3 tissue layers
• Includes free-living flatworms and parasitic flatworms (tapeworms, flukes)
CLASSES OF FLATWORMS
• Class Turbellaria – free-living flatworms
• Class Cestoda – tapeworms
• Class Trematoda - flukes
Flatworm
Flatworm
Tapeworm head (scolex)
Liver fluke
Phylum Annelidasegmented worms
• Earthworms, sandworms, leeches
• One-way digestive system
• Have well-developed digestive and circulatory systems
CLASSES OF ANNELIDS
• Class Oligochaeta – earthworms, bloodworms; oligo- means “few” and chaeta means a “bristle” or stout hair
• Class Polychaeta – many bristles and parapodia (fleshly lobes to “walk” with
• Class Hirudinea – leeches (most are NOT bloodsuckers)
Christmas tree worm
Feather-duster worm
Fireworm
Nereis – a polychaete
Oligochaete
Phylum Mollusca-soft bodied animals
• includes snails, slugs, nudibranchs, chitons, limpets, clams, oysters, squid, octopus, nautilus, etc.
• Either have no shell, one shell, or two shells
• Many have hard mouth parts (radula in gastropods, beak in cephalopods).
CLASSES OF MOLLUSCS
• Class Gastropoda – snails, slugs, conchs, nudibranchs; have either no shell or one shell; name means “stomach foot”
• Class Bivalvia – clams, oysters, mussels; have two shells that hinge together
• Class Polyplacophora – chitons; snail-like with 8 embedded plates on its back
• Class Cephalopoda – squid, octopus, nautilus, cuttlefish; name means “head foot”; well-developed nervous system
Nudibranch
Blue-ring octopus
Chambered nautilus
Oyster on half-shell(needs Tabasco)
Phylum Arthropoda – joint-legged animals
• includes insects, crustaceans, centipedes, millipedes, and arachnids
• exoskeleton made of chitin
• must shed shell to grow
CLASSES OF ARTHROPODS
• Class Crustacea – shrimps, lobsters, crabs, crawfishes
• Class Amphipoda – small; called scuds• Class Isopoda – sea lice; some are parasitic• Class Stomatopoda – mantis shrimps• Class Pycnogonida – sea spiders• Class Merostomata – horseshoe crabs• Class Cirripedia - barnacles
Bulldozer larva - Crustacea
Bulldozer
Cleaner shrimpCrustacea
Spider crabCrustacea
Crab zoeacrustacea
Crab megalops
Hermit crab - crustacea
Amphipoda
Giant Isopod
Parasiticisopod
Ligia exotica - isopod
Mantis shrimp - Stomatopoda(thumbsplitter)
Horseshoe crabMerostomata
Sea spider- Pycnogonida
Barnacles - Cirripedia
Phylum Echinodermata –spiney-skinned animals
• includes sea stars, brittle stars, sea urchins, sand dollars, sea cucumbers, and crinoids
• reverted back to radial symmetry (radial in adults / bilateral in larvae)
• tube feet and water vascular system
• Most exhibit pentamerism
WHY ARE ECHINODERMS RANKED SO HIGH?
• Clues from embryology – study of the early development of animals
• Protostomes versus Deuterostomes
• Protostome – blastopore forms the mouth in all animals except echinoderms and chordates
• Deuterostomes – blastopore forms the anus in echinoderms and chordates
CLASSES OF ECHINODERMS
• Class Asteroidea – sea stars
• Class Ophiuroidea – brittle stars, serpent stars
• Class Echinoidea – sea urchins, sand dollars
• Class Holothuroidea – sea cucumbers
• Class Crinoidea – sea lilies, feather stars
Sea star - Asteroidea
Bat star - Asteroidea
Pycnopodia - Asteroidea
Brittle star - Ophiuroidea
Sea urchin - Echinoidea
Purple urchinsEchinoidea
Sand dollar - Echinoidea
Sea cucumberHolothuroidea
Feather star - Crinoidea
Phylum Chordata
• Includes fish, amphibians, reptiles, birds, and mammals
• Chordate characteristics:
• Dorsal hollow nerve tube
• Notochord
• Pharyngeal gill slits
• Post anal tail
CHORDATE CLASSIFICATION
• The Protochordates - invertebrate chordates
• Subphylum Urochordata – sea squirts, salps, and ascidians
• Subphylum Cephalochordata – lancelets
• True Chordates:
• Subphylum Vertebrata
Tunicate - Urochordata
Tunicate - Urochordata
Salp- Urochordata
CEPHALOCHORDATEAmphioxus
SUBPHYLUM VERTEBRATA
• Class Agnatha – jawless fishes; lampreys and hagfishes
• Class Chondrichthys – cartilaginous fishes; sharks, rays, skates, chimeras
• Class Osteichthys – boney fishes• Class Amphibia – frogs, salamanders• Class Reptila – turtles, snakes, lizards, and
crocodilians• Class Aves – birds• Class Mammalia - mammals
VERTEBRATE BODY PLAN
• Recapitulation Theory – Ontogeny recapitulates Phylogeny
• The embryological and developmental changes an organism goes through restates its evolutionary history
• Evolution cannot go back and change history…it can only modify what is pre-existing
Sea lamprey - Agnatha
Hagfish - Agnatha
Great white shark - Chondrichthys
Tiger shark - Chondrichthys
Manta ray - Chondrichthys
Stingray - Chondrichthys
Ratfish (Chimera)- Chondrichthys
Electric ray - Chondrichthys
Leafy sea dragon - Osteichthys
Sargassum fish - Osteichthys
Deep sea angler fish - Osteichthys
Clown anemone fish - Osteichthys
Bull dolphin - Osteichthys
Bullfrog - Amphibia
Green sea turtle Reptila
American alligator - Reptila
Osprey - Aves
Great blue heron - Aves
Humpback whales - Mammalia
Sea lionMammalia