Animal body plans II Choanoflagellates Fungi Porifera (Sponges) Major animal Animalia multicellularity Ctenophora phyla
Cnidaria
diploblasty Acoels LOPHOTROCHOZOAN Rotifera Loss of coelom Platyhelminthes triploblasty Segmentation Annelida Protostome development PROTOSTOMES Mollusca BILATERA ECDYSOZOA Nematoda
Cephalization, CNS, coelom Arthropoda Segmentation DEUTEROSTOMES Echinodermata Radial symmetry (adults) DEUTEROSTOMES Deuterostome development Chordata Segmentation Freeman 2014 Three tissue layers
• Acoels • No coelom • Bilaterally symmetric • Simple digestive tract (no gut, no specialized Symsagittifera roscoffensis digestive cells) • Sac body plan • Cilia cover body • Asexual and hermaphroditic
Porifera
The protostomes ANIMALS Ctenophora Cnidaria
Acoela
LOPHOTROCHOZOA Rotifera
Platyhelminthes
Annelida PROTOSTOMES Mollusca Protostome development ECDYSOZOA Nematoda
Tardigrada
Coelom Onychophora
Arthropoda
Echinodermata
Chordata LOPHOTROCHOZOA Water-to-Land Transition Rotifera
Platyhelminthes
Annelida
Mollusca All aquatic ECDYSOZOA Some terrestrial Nematoda All terrestrial
Tardigrada
Onychophora
Arthropoda
Echinodermata
Chordata Protostomes - Lophotrochozoa
(a) Lophophores function (b) Trochophore larvae in suspension feeding swim and may feed. in adults.
Food particles
Water current Anus Mouth Mouth (in the center Cilia used in of the ring locomotion of ciliated and feeding tentacles) Anus Gut 0.1 mm 0.1 mm
(a) Mouthparts for (b) Mouthparts for (c) Mouthparts for suspension deposit feeding mass feeding feeding
Eversible proboscis with sharp fangs impales prey
Feathery mouthparts capture Long, sticky tentacles reach plankton across substrate and deliver organic particles to mouth (worm body remains hidden) Porifera MALS Ctenophora Rotifera Cnidaria
Acoela
LOPHOTROCHOZOA • Bilateral symmetry Rotifera • Three germ layers Platyhelminthes • pseudocoelomate Annelida
PROTOSTOMES • digestive tract with Mollusca Protostome development 2 openings ECDYSOZOA Nematoda
Tardigrada
Coelom Onychophora
Arthropoda
Echinodermata
Chordata 8 Porifera MALS Ctenophora Platyhelminthes Cnidaria
Acoela
LOPHOTROCHOZOA • Bilateral Rotifera symmetry Platyhelminthes • Three true tissue Annelida layers (ectoderm, PROTOSTOMES Mollusca Protostome endoderm and development ECDYSOZOA mesoderm) Nematoda • acoelomate Tardigrada • sac body plan Coelom Onychophora
Arthropoda
Echinodermata
Chordata 9 Planarian
Nervous System
branching gut
pharynx (protruded)
Digestive system Reproductive System 10 Porifera MALS Ctenophora Annelida Cnidaria
Acoela
LOPHOTROCHOZOA • Bilateral Rotifera symmetry Platyhelminthes • Three germ Annelida layers PROTOSTOMES Mollusca Protostome • coelomate development ECDYSOZOA Nematoda • complex digestive tract Tardigrada with 2 openings Coelom Onychophora • Segmentation Arthropoda
Echinodermata
Chordata 11 Annelids: Segments Galore
• Segments have bristles (chaetae or setae)
• Oligochaetes (few bristles)
• Polychaetes (many bristles)
• Leeches (none)
12 Annelids use their chaetae for burrowing
• Midbody, transverse section of earthworm longitudinal muscles dorsal blood coelom cuticle circular vessel muscles Clitellum
seta (retracted) nephridium ventral blood nerve cord vessel Hydrostatic skeleton
13 Porifera MALS Ctenophora Mollusca Cnidaria
Acoela
LOPHOTROCHOZOA • Bilateral Rotifera symmetry Platyhelminthes • Three germ Annelida layers PROTOSTOMES Mollusca Protostome • coelomate development ECDYSOZOA Nematoda • complex digestive tract Tardigrada with 2 openings Coelom Onychophora
Arthropoda
Echinodermata
Chordata 14 Common Molluscan themes
• muscular foot and a mantle • shell which encloses the visceral mass • A true coelom, reduced, limited to region around the heart • Circulatory system • Radula
15
Diverse Molluscan Body Plans
• A bivalve
16 Molluscan locomotion
17 Figure 34.8
Stripes are waves of muscle contraction Diverse Molluscan Body Plans: Cephalopods • Squid – supreme predators
19
Diverse Molluscan Body Plans: Gastropods
• A gastropod – a “mistake” in evolutionary experimentation? Torsion of viscera
BEFORE TORSION AFTER TORSION mouth mouth anus
anus, which discharges into mantle cavity
21 Diverse molluscs: gastropods
22 Protostomes - Ecdysozoa
(a) Lophotrochozoans grow b) Ecdysozoans grow incrementally. by molting.
Cuticles or exoskeletons
Growth bands Porifera MALS Ctenophora Nematoda Cnidaria
Acoela
LOPHOTROCHOZOA • Bilateral symmetry Rotifera • Three germ layers Platyhelminthes • pseudocoelomate Annelida
PROTOSTOMES • digestive tract with Mollusca Protostome development 2 openings ECDYSOZOA Nematoda
Tardigrada
Coelom Onychophora
Arthropoda
Echinodermata
Chordata 24 Roundworms thrive in nearly all environments
mouth • Cylindrical body piercing device (retracted) • Cuticle ring of nerves pharynx • Complete digestive system intestine • Male and female psuedocoelom
ovary (eggs cuticle over develop here) epithelial tissue and muscle cells
pore (sperm enter and eggs are released through this one) anus 25 Roundworm locomotion Porifera MALS Ctenophora Tradigrada Cnidaria
Acoela • Bilateral symmetry LOPHOTROCHOZOA Rotifera • Three germ layers Platyhelminthes • coelomate Annelida • complex digestive PROTOSTOMES Mollusca tract with 2 Protostome development openings ECDYSOZOA Nematoda • segmentation Tardigrada
Coelom Onychophora
Arthropoda
Echinodermata
Chordata 27 Tardigrada Porifera MALS Ctenophora Onychophora Cnidaria Acoela • Bilateral symmetry LOPHOTROCHOZOA • Three germ layers Rotifera • coelomate Platyhelminthes • complex digestive Annelida tract with 2
PROTOSTOMES openings Mollusca Protostome development • Segmented ECDYSOZOA Nematoda • Stub feet • Velvet worms Tardigrada
Coelom Onychophora
Arthropoda
Echinodermata
Chordata 29 Porifera MALS Ctenophora Arthropoda Cnidaria
Acoela • Bilateral symmetry LOPHOTROCHOZOA Rotifera • Three germ layers Platyhelminthes • coelomate Annelida • complex digestive PROTOSTOMES Mollusca tract with 2 Protostome development openings ECDYSOZOA Nematoda • Segmentation Tardigrada • exoskeletons
Coelom Onychophora
Arthropoda
Echinodermata
Chordata 30 Arthropods – most successful organisms
(Other than prokaryotes) • Over one million species Major lineages:
Chelicerates Trilobites Crustaceans (extinct)
Uniramians 31 Adaptations of Arthropods
• Hardened exoskeleton • Jointed appendages • Fused and modified segments • Head, Thorax, Abdomen
32 Adaptations of Arthropods
• Specialized respiratory structures • Gills or tracheas • Efficient nervous system and sensory organs • Eyes - vision • Divisions of labor in the life cycle • Metamorphosis • Growth • Molting
33 A Look at Crustaceans
• Vast majority are marine • Lobsters, crabs, shrimps
• Copepods • Less than 2mm long
• Barnacles • Calcified shell
34 Crustaceans
35 Barnacle biology Uniramians
• Include insects, millipedes, and centipedes. • Head and thorax limbs one branch • Paired head appendages • Tracheae • Metamorphosis
37 Chelicerates
• Include terrestrial spiders, scorpions, ticks, mites, horseshoe crabs and sea spiders. • First pair of appendages (chelicerae) are feeding organs. • Second pair of appendages (pedipalps) function in feeding or sensory. • All appendages attached to cephalothorax. • No appendages on heads.
38 Porifera
ANIMALS Ctenophora Deuterostomes Cnidaria Acoela
PROTOSTOMES Rotifera
Platyhelminthes Annelida Mollusca Nematoda
Tardigrada Onychophora
Arthropoda
DEUTEROSTOMES Echinodermata
Hemichordata
Xenoturbellida Deuterostome development Chordata (includes vertebrates) Porifera
ANIMALS Ctenophora Echinodermata Cnidaria Acoela
PROTOSTOMES • Symmetry?! Rotifera Platyhelminthes • Three germ layers Annelida Mollusca • Coelomate Nematoda • digestive tract with Tardigrada Onychophora 2 openings
Arthropoda
DEUTEROSTOMES Echinodermata
Hemichordata
Xenoturbellida Deuterostome development Chordata (includes vertebrates) 40 The Puzzling Echinoderms
• Why puzzling? • bilateral larvae (usually) • radially symmetrical Anus adults Spines
Tube feet
Stomach
TUBE FEET
CANALS 41 Echinoderm diversity
42 Porifera
ANIMALS Ctenophora Chordates Cnidaria Acoela
PROTOSTOMES • Symmetry?! Rotifera Platyhelminthes • Three germ layers Annelida Mollusca • Coelomate Nematoda • digestive tract with Tardigrada Onychophora 2 openings
Arthropoda
DEUTEROSTOMES Echinodermata
Hemichordata
Xenoturbellida Deuterostome development Chordata (includes vertebrates) 43 Features of Chordates
• A notochord
• A tubular dorsal nerve chord
• Embryos have distinctive silts in wall of pharynx, a muscularized tube
• A tail forms in embryos and extends past anus
mammals
birds
reptiles
amphibians
bony fishes
cartilaginous Invertebrate Chordates
chordate ancestral fishes jawless fishes
lancelets no vertebrae 45 Subphylum: tunicates
a. Larval form nerve cord notochord
intestine
b. Larval metamorphosis oral opening
atrial opening (exit of water) pharynx with gill slits
46 Subphylum: lancelets
DORSAL, TUBULAR TAIL EXTENDING NERVE CORD PHARYNX WITH PAST ANUS NOTOCHORD GILL SLITS
aorta anus epidermis gonad hindgut pore of segmented midgut tentacles atrial cavity around muscles mouth
• Unlike Tunicates, have a closed circulatory system, • but not red blood cells •Filter47 feeders mammals
birds reptiles amphibians vertebrae bony fishes Subphylum: Vertebrae cartilaginous fishes jawless fishes
tunicates
lancelets 48 Vertebrate developments
• Living Endoskeleton • includes a skull • backbone is composed of vertebrae Backbone
• Paired limbs
• High degree of cephalization
• Efficient respiration & excretion
• Closed circulatory system
49 Vertebrate developments
supporting structures • Most vertebrates have Jaws Early jawless fish (an Agnathan) gill slit
Early jawed fish (a Placoderm) jaw spiracle (small gill slit) jaw support
Modern jawed fish (a shark) jaw
50