The Animal Kingdom

Characteristics of Animals• Multicellular eukaryotes• Heterotrophic• Gametic Life Cycle

(dipoid/meiosis/gametes/fertilization/zygote/ embryo with 3 cell layers (not in all)• Are motile at some stage of development• Have no cell walls • Symmetry (body form) radial or bilateral• Cephalization in some (head end w/nerve

tissue)• Type of gut – sac-like with only mouth;

complete digestive tract

X

Animal Kingdom – Phylogenetic Tree

Phylum Phoronida• Phoronida - one of the smallest and

least familiar phyla; there are about twelve living species.

• Phoronids -- or "horseshoe worms," as they are sometimes called -- abundant in shallow marine sediments at certain localities.

• Phoronids are elongated and worm- shaped, but the gut loops and ends close to the mouth, instead of passing straight through the body as in annelids and many other wormlike organisms.

• The mouth is surrounded by the ciliated feeding structure known as a lophophore.

• Live in tubes created by worm – tube worms

Classification Criteria

• Embryology – development

• Biochemistry – metabolic “pathways” similarity

• Genetics – DNA analysis

Subkingdoms

• Parazoa – lacking tissues -not microscopic Sponges (Porifera)• Mesozoa – no tissues/organs…primitive parasites (small, worm-like, 20-50 cells, parasitize cephalopods, echinoderms, mollusks)

• Eumetazoa – true tissues in germ layers and organs (ectoderm, mesoderm, endoderm)

All other animal phyla

Possible Ancestors of Animals??

Codosiga – a protozoan – called a choanofagellate – has a structure similar to choanocytes in sponges

Proterospongia

This colonial protozoan is studied by zoologists because of intercellular signaling and adhesion

Sponges – Phylum Porifera

• Means pore-bearing• No true tissues –

specialized cells• Asymmetrical• Adults sessile; larvae

motile• “Zoophytes”• Types: Simple – Ascon Corrugated – Sycon Complex - Leucon

x

Ascon (simple sac type)

Osculum

Water flow

Cell Types of Sponges (no tissues)

• Epidermal – flattened -cover sponge surface - protection

• Choanocytes – collar cells – flagellated -trap food/engulf – line spongocoel

• Porocytes – cells on either side of incurrent pores

• Amoebocytes – amoeba like – digest food & distribute – in mesoglea layer

• Amoebocytes – also make silica based spicules and spongin (structural protein),

and function in reproduction

Sponge “Support”

• Body of sponge stiffened by:

1. Spicules (CaCO3, silica)

2. Tough protein fibers - spongin

Spicules

Other Significant Structures• Osculum – large opening – at top – water

flows out of sponge

• Ostia – aka incurrent pores

Reproductive Modes• Sexual Reproduction

1. Hermaphroditic – eggs/sperm produced on same animal 2. Gametes produced in mesenchyme layer – special amoebocytes 3. Some species x-fertilize; some self 4. Zygote grows by mitosis – larvae flagellated – swims then sessile• Asexual Reproduction Budding on parent; Gemmae internally

Sycon Sponges

Leucon Sponges - solitary

Leucon Sponges - Encrusting

Gemmules - Asexual

Cluster of amoebocytes w/ spicules

Radial vs. Bilateral Symmetry

Eumetazoa (true tissues)Phylum Cnidaria ( Coelenterates)

“Stinging celled animals”

• Class: Hydrozoa – Hydroids• Class: Scyphozoa - Jellyfish• Class: Anthozoa – Corals, Sea Anemone,

Sea Fans

Polyp and Medusa Forms

Cnidaria - Body Forms

Hydra

Structure of Hydra

Tissues – 2 true layers• Ectoderm

Epidermis –outer layer -protection (special cells – form ovary, testes- zygote forms flagellated larva –planula)

Asexual by buddingCnidoblasts – stinging cells -

Nematocysts are stingers• Mesoglea – gelatinous layer- not cellular;

has Nerve cells – form nerve network; in contact

w/ epidermis, gastrodermis Contractile fibers – movement

Cnidoblast/Nematocyst

• Endoderm Gastrodermis – for nutrition; lines the gastrovascular cavity – mouth at center of tentacles

Colonial Hydroid - Obelia

Obelia – Life Cycle (Hydroid Colony)

Colonial Hydroid - Portuguese Man-O-War

Individual animalslive above tentalces

Scyphozoa – Jelly Fish

Jellyfish Life Cycle

Planula

Sperm

Eggs

Aurelia

Anthozoans - Anemones

Anatomy of Anemones (“flower animals”)

Threads loadedwith nematocysts

Anthozoa - Corals

Coral Reef

Zooxanthellae/Zoochlorellae

Symbiotic relationship –algae reside in animals' gastrodermal cells- sea anemone benefits from algae's photosynthesis (oxygen, food) -algae in turn are assured a reliable exposure to sunlight and protection from micro-feeders,

Sea anemone tentacles

Phylum Ctenophora•Comb jellies (aka - sea gooseberries) are one of the most beautiful animals to inhabit the ocean – 90 species

• 2nd phylum of radially symmetrical animals

•Named for rows of comb-like cilia in bands on body

•Use tentacles to trap prey- do not sting prey

Protostome or Deuterostome?

Coelom Evolution

Cleavage Comparison

Protostome Worms

Phylum Platyhelminthes(Flatworms)

• Flattened dorsoventrally

• Acoelomate• 3 distinct tissue

layers• Turbellaria – Free

living flatworms – Planaria

• Trematoda – Liver flukes and Blood Flukes

• Cestoda - Tapeworms

Class: Turbellaria - Planaria

•Sac-like gut•Bilateral symmetry•Cephalization with eyespots, ganglia, nerve cords•Acoelomate•3 tissue layers (ecto,meso,endo)•Cell to cell diffusion•Primitive kidney – protonephridia with flame cells•Hermaphroditic – cross fertilize•Regeneration studies•Systems: Digestive Nervous Reproductive Excretory

Organ Systems of Planaria

Other Turbellarians

Class: Trematoda Liver Flukes

Human Liver

Fluke – Life Cycle

Trematodes – Blood Fluke (Schistosoma)

•Causes “Swimmers itch”•Requires 2 hosts – one for reproduction, one for development

Cestoda - Tapeworm

Tapeworm Anatomy

Proglottid

Scolex

ROSTRUM SUCKERS

Beef Tape Worm – Life Cycle

(measley beef – encysted larvae))

gravidproglottids

Phylum Nemertea – Ribbon Worms

proboscis

Ribbon Worms

• Aquatic,sandy areas• One way gut-

mouth,anus• Proboscis – fires out –

lined with nail shaped spines –wrap around prey

• Can be 3 x body length

• Separate sexes• Eat small

invertebrates or scavenge

Ribbon Worm Anatomy

Protostome Worms

Phyla

Phylum Nematoda (roundworms)•25,000 species•Parasitic & some free living•Habitats – aquatic, terrestrial, parasitic•Cuticle covers body (note striations)-protects•Digestive tract with mouth,anus•Pseudocoel – hydrostatic skeleton•Nervous system – nerve ring, dorsal & ventral nerve cords•Respiration - diffusion•Dioecious –separate sexes •200,000 eggs/day

Nematode Anatomy

Ascaris Infestation

Can cause intestinal blockage

Dirofilaria immitis (dog heartworm)

Filiaria worm in bloodstream

HeartwormLife Cycle

Worms, Worms, and More Worms…

Guinea Worm – Dracunculus mediensisAfrica – adult female 3 feet long – comes through skin;

Water flea has larvae – man drinks water w/fleas;Natives wind on a stick until it comes out

And more….

•Filaria worms – Wuchereria sp.

•Elephantiasis

•Hosts – mosquito, man

•Worms – 1/1000 of an inch block lymphatic system causing severe edema (swelling)

•Tropical areas

And more…

•Loa loa worm

•Worm migrates through subdermal tissue – can go across eye

•West Africa

Ancylostoma duodenale or Necator americanus

•Buccal cavity with hooks•Hook to intestinal wall – causes anemia, bleeding

Trichina (pork worm) – “Trichinosis”

Worm encysted in muscle tissue – undercooked pork products

Acanthocephala – Spiny Headed Worms•Retractable proboscis armed w/curved hooks

•Parasites in vertebrates (1000 in seal’s gut)

•No digestive tract-diffusion through cuticle

•Dioecious

Phylum Rotifera“wheel animals”

•Cilia beating around mouth –looks like wheel rotating

•Tail-like foot - attaches

•Dioecious

•Digestive tract with mouth and cloaca (important !)

•Excretory system-flame cells – bladder/water balance organ also

•Important food chain members

COELOMATES

Highly developed invertebrates & vertebrateshave a internal body cavity outside intestinal

tract.

• Allows organs to develop & work more freely - not pushing against muscles

• Can provide hydrostatic skeleton

(fluid –filled coelom works with muscles

to change body shape)

• Provides protected space for production of sperm and ova

Coelom Advantages

Protostomes vs Deuterostomes

• Coelomate Protostomes:

Annelids (segmented worms)

Mollusks (soft bodied animals)

Arthropods (jointed appendages)

Coelomate Deuterostomes Echinoderms (spiny skin) Chordates (vertebrates &

notochord animals)

Protostomes vs Deuterostomes

Phylum Mollusca (Latin – molluscus -soft-bodied)

• 2nd largest phylum• Bilateral symmetry• Type of shell & foot used to classify• Torsion in Gastropods – 180 °• Mantle- makes shell• Mantle cavity – encloses gills or lungs • Visceral mass – digestive, excretory, reproductive• Foot – muscular for movement; can be modified into

tentacles• Radula – rasping tongue with microscope teeth –

tears, shreds, bores holes in mollusk shells• Trochophore and Veliger larval stages in some

Classes of Mollusca

• Aplacophora – Chaetoderma

• Monoplacophora - Neopilina

• Polyplacophora – Chitons

• Scaphopoda – Tooth shells

• Gastropoda – Snails, slugs, whelks

• Bivalvia – Clams, mussels, oysters, scallops

• Cephalopoda – Squid, octopus, nautilus

Gastropoda Respiration•Aquatic snails – gills•Terrestrial snails – mantle cavity

Snail “Tongue”

Radula – Snail Tongue

Gastropoda

Bivalvia

Muscular Foot

•Used for movement•May be modified into tentacles

Larval Forms of Mollusks

Trochophore

Veliger

Aplacophora

•No shell•Reduced foot•Move w/cilia•Benthic(bottom)•Deep water•5cm–30 cm•Epidermis secretes calcareous spicules

Monoplacophora Neopilina

•“single-plate bearer”•1952 rediscovered•Costa Rica•3,590 meters

Polyplacophora Chitons

•Ancient class•Notable – 8 dorsal plates•Herbivores

Scaphopoda – Tooth Shells (Tusk Shell)

•Elongated shell •Sticky tentacles – catch prey•Marine – sandy bottom

Gastropoda

Featuring - Gastropoda

• Snails, conchs, abalones, slugs, nudibranches (poisonous), limpet, etc.• Stomach-footed• Univalve – most• Respiration – gills or mantle cavity• Snails – eyes on tentacles (light, touch)• Radula (food shredding tongue)• Only mollusk to invade land

Bivalvia

Cockles Giant clam

Oyster

Mussel

Scallop

Here-s-s-s….Bivalvia

• Formerly called Pelecypoda (hatchet-foot)• 2 shells• Marine & freshwater• Filter feeders (incurrent siphon, labial palps

funnel to mouth)• Gills• Shells – CaC03 – mother of pearl buttons• Open circulatory system• Dioecious• Mussels, oysters are sessile as adults• Scallops swim by “clapping action” of shells

Cephalopoda

BAD

SQUID

Cephalopoda Talk About a Big Head…

• Squid, octopus, cuttlefish, chambered Nautilus• Predators• Can swim, crawl, jet propulsion (siphons)• Tentacles (modified foot) – suckers• Well developed eyes, nervous system• Defense – “inky spray” – foul tasting• Chromatophores –change color to match environment• Shells – octopus (none), squid – internal pen, cuttlefish – coiled, flat, plate-like… Pet bird cuttlebone

Mollusk “Claim to Fame”

• Important food sources – man

• Research – snails – cancer free

• Pollution indicators

• Snails/slugs – crop damage

• Shipworms – damage docks, boats

• Filter feeders – can concentrate toxins – human consume – sick/die

• Octopus – beak; also learning & memory

Segmented Worms

Phylum Annelida ~ Characteristics

• True coelom - coelomate

• Hydrostatic skeleton

• Segmentation (metameres)

• Closed blood vascular system

Oligochaeta - Earthworms

•Nephridia – tubules remove liquid wastes•Digestive system –mouth-pharynx-crop- gizzard- intestine- anus•Circulatory system – closed – 1st distribution tissue•Respiration – moist skin – diffusion•Nervous system – cerebral ganglia, nerve cord•Reproduction – hermaphrodite – cross fertilize; clitellum•Muscular system – circular & longitudinal•Environmental benefit – castings fertilize soil, aeration of soil

•Segmented body•Metameres – adaptation for burrowing•Setae for movement

Earthworm Anatomy

Polychaetes - Marine – Sand & Tube Worms

Hirudinea - Leeches

I Am Stuck on YOU !!!

• Ectoparasites –sanguivorus – blood sucker

• Sacculated intestine – stores blood – several months between feedings

• Hirudin – anticoagulant

• Anterior/posterior suckers

• Sense light/temperature changes, vibrations

• Sensory cells – smell; may have eyes

Phylum Onychophora – Velvet Worms

• Phylum means “claw-bearers”•Terrestrial, tropical, moist habitats•Antennae & clawed legs•Carnivores•Papillae on surface give velvety appearance•May be “missing link” between annelids and arthropods

Trilobites

•Extinct ancient arthropods•Mass Extinction 250 mya

Phylum Arthropoda

• Most successful group of animals…species diversity, distribution, vast numbers

• Segmentation in body• Hard exoskeleton (chitin and protein) – molt to grow

– muscles attach; prevents desiccation• Jointed appendages (feeding, movement, mating,

defense, mating)• Extensive cephalization & sensory organs• Open circulatory system – hemolymph• Gas exchange – varies from gills/tracheal

tubes/book lungs

Phylum Arthropoda Subphylum ChelicerataClass Meristomata

Horseshoe Crab

Phylum Arthropoda Subphylum ChelicerataClass Arachnida

Have chelicerae – claw like appendage for feeding – fangsin spiders

Phylum Arthropoda Subphylum CrustaceaClass Malacostraca

Crayfish External Anatomy

Crayfish – Internal Anatomy

Phylum Arthropoda Subphylum CrustaceaClass Maxillopoda

Phylum Arthropoda Subphylum Uniramia Class Chilopoda

Centipedes – 1 pr legs/segment; carnivores; poison claws

Phylum Arthropoda Subphylum UniramiaClass Diplopoda

Millipedes – 2 prs legs/segment; vegetarians

• More known species than all other groups• Body regions – head, thorax, abdomen• Mouthparts very diverse – biting, sucking, chewing,

piercing,etc.• 1 pr antennae; pr of compound eyes• Complete digestive tract• Nervous system – cerebral ganglia with nerve cords• Malpighian tubules – excretion of liquid wastes• Tracheal tubes from spiracles for respiration• Ovipositor for laying eggs• Wings/flight –major adaptation for success of insects• Incomplete metamorphosis; complete metamorphosis

Phylum Arthropoda Subphylum UniramiaClass Insecta – 32 orders

Insect Anatomy

Compound Eye

Especially good for detecting motion…

x Metamorphosis

Incomplete – young are smaller versions of adult

Complete – egg to larvae – eats/grows – pupates -adult

Thysanura - silverfish

Odonata – Dragonfly and Damselfly

Orthoptera – Grasshopper and Cricket

Blattaria - Cockroach

Isoptera - Termite

Anoplura - Louse

Hemiptera – true bugs

Homoptera – Aphid, Leafhopper, Cicada, Scale Insect

Lepidoptera – Moths, Butterflies

Diptera – Flies and Mosquitoes

Siphonaptera - Flea

Coleoptera - Beetles

Hymenoptera – Ants, Bees, and Wasps

Deuterostomes

X Phylum - Echinodermata

• Asteroidea – Sea Stars

• Crinoidea – Sea Lilies

• Echinoidea – Sand Dollars and Sea Urchins

• Ophiuroidea – Brittle Stars

• Holothuroidea – Sea Cucumbers

Echinoderm Characteristics

• Bilateral bipinnaria larval stage to pentaradial adults

• Spiny skin – subcutaneous calcareous plates (endoskeleton)

• Water vascular system –hydraulic canals control tube feet

• Stomach everts through mouth to feed in starfish

• Dermal Branchia for respiration

Bipinnaria LarvaMouth

Esophagus

Stomach

Asteriodea - Sea Stars (Star Fish)

Water Vascular System

Dermal Branchiae

Pedicellariae

CrinoideaCrinoidea – Sea Lily

Echinoidea – sand dollars, sea Echinoidea – sand dollars, sea biscuits, sea urchinsbiscuits, sea urchins

Ophiuroidea

HolothuroideaHolothuroidea

Phylum - Hemichordata

• Enteropneusta (acorn worms)

• Graptolithina (graptolites) extinct

• Pterobranchia (pterobranchs) 20 sp.

Acorn Worms - to 8 ft

Tornaria Larva

Pterobranchs – Rhabdopleura – 1 mm

Phylum Chordata3 subphyla

• Cephalochordata - Amphioxus

• Urochordata – Sea squirts

• Vertebrata – Animals with vertebrae

here

Chordate Characteristics

• Notochord -cartilage rod (endoskeleton)

• Dorsal Hollow Nerve Cord

• Myotomes – segmented muscle bundles

• Pharyngeal gill slits – gill basket

• Post-anal tail

Cephalochordates – Amphioxus

Urochordates – Tunicates (sea squirts)

Ostracoderms

Phylum - Chordata Subphylum - Vertebrata Class - Agnatha

Hagfish

Evolution of Jaws

Placoderms

Class Chondrichthyes

Lobe-finned Lung Fish

Class Osteichthyes – boney fishes

Class Amphibia

Class Reptilia

Class Aves

Class Mammalia

3 subclasses

Monotremata – Platypus and Echidna

Marsupiales – Marsupials

Placentals – Mammals that have placenta

Monotremes

Peleomaps

Marsupials

Placental Mammals – 19 Orders

Insectivora

Chiroptera

Carnivora

XenarthraXenarthra

RodentiaRodentia

LagomorphaLagomorpha

Pika

PerissodactylaPerissodactyla

ArtiodactylaArtiodactyla

Proboscidea

SireniaSirenia

CetaceaCetacea

PinnipediaPinnipedia

PrimatesPrimates

Tarsier