Phylogentic Relationships of Animals
Ancestral Protist
segmentation
true tissue
radial symmetry
bilateral symmetry
Deuterostomes:eucoelom
Protostome: schizocoelem
pseudocoelom
Porifera
Cnideria
Platyhelminthes
Nematoda
Mollusca
AnnelidaEchinodermata
ChordataArthropoda
no true tissues
acoelom
• Eukaryotic, multicellular organisms with cells organized into distinct tissues.
Heterotrophic nutrition
Most exhibit significant capacity for locomotion.
No cell walls; has a plasma membrane.
Includes sponges, sea anemones, snails, insects, sea stars, fish, reptiles, birds, and human beings.
Kingdom AnimaliaKingdom Animalia
Phylum Porifera
Class Desmospongiae
Class Calcarea
Class Hexactinellida
Class Sclerospongia
• No true tissues or organs• No symmetry• No nerves, muscles, mouth or
digestive system or • Sessile• Reproduce sexually and asexually• Skeletons composed of CaCO3 or
SiO2 spicules or spongin• Filter feeders
Phylum Porifera
5,000 species
Consists of organized cells supported by a skeleton of:
• spongin fibers• calcareous spicules• silica spicules• a combination of these, or perhaps no skeletal
structure at all
No GutSponges
Phylum PoriferaSponges
Phylum Porifera
• A few species of fish• seaslugs • hawks bill and loggerhead turtles
• Can use toxins to ward off predators
• Sponges provide habitat for wide variety of animals.
• As many as 16,000 different species of animals have been found in one loggerhead sponge.
• Most marine sponges (>80%)• All freshwater sponges• Leuconoid• Spongin and SiO2 spicules
• Contains all asconoid forms• Most syconoids• Generally small in stature• CaCO3 spicules
• Mostly deep sea forms • Glass-like lattice work• SiO2 spicules
• CaCO3 foundation with SiO2 spicules• Found in Pacific and West Indies
Asexual: • production of external buds that detach or remain to
form colonies • internal buds called gemmules that form during
unfavorable periods• fragmentation (regeneration)
Sexual (mostly hermaphroditic):• eggs are retained in the mesohyl and fertilized by
motile sperm that enter through the internal canals. Zygotes develop into flagellated larvae, which break loose and are carried away by water currents.
Phylum Cnidaria
Class Anthozoa
Class Hydrozoa
Class Scyphozoa
Class Cubozoa
CoralsAnemones
HydraPortuguese Man-Of-War
Stinging LimuFire Coral
True jellyfish Box jelliesSea wasps
Phylum Cnidaria
Stinging cells & 2 stages in life cycle
Radial symmetry
Tissues and organs
Diploblastic
Mouth and digestive cavity (blind sac gut)
9,000 species
Polyp Medusa
gastrovascular cavity
gastrovascular cavity
gastrodermis
mesoglea
epidermis
mouth/anus
mouth/anus
The Cnidarian Life Cycle
The Hydrozoan Life CycleThe Hydrozoan Life Cycle
Nematocysts
“Stinging Limu”
Class Hydrozoa
Hydrozoan Medusa
Close Up of a Portuguese Man-Of-War
Class Hydrozoa
Class Scyphozoa
Box Jellies
SeawaspClass Cubozoa
Subclass ZoanthariaOrder ActinariaSea Anemones
Class Anthozoa
Subclass HexacoralliaOrder Antipatheria
Black Coral & Wire Coral
Wire coral
Black coral
Class Anthozoa
“True” Stony Coralslobe
finger
mushroom
Porites rus
Class Anthozoa
Phylum Ctenophora
• Diploblastic• 8 rows or combs of cillia• Colloblasts- adhesive structures• Hydrostatic skeleton• Blind sack gut
Phylum Platyhelminthes
Class Turbellaria
Class Trematoda
Class Cestoda
Phylum Platyhelminthes
Flatworms
Blind digestive cavity
Bilaterally symmetrical
Thin, simple circulation
Sensory organs at front
Many parasitic
10,000 species
Fig. 33-10
Pharynx
Gastrovascularcavity
Mouth
Eyespots
Ganglia Ventral nerve cords
Class Turbellaria
Flatworm Anatomy
Pseudoceros dimidiatus
Pseudoceros cf. rubroanus
Pseudoceros ferrugineus
Pseudobiceros sp.
Planocera cf. oligoglena
Life History of a Blood FlukeClass Trematoda
Class Cestoda
• Bilaterally symmetrical and dorsoventrally flattened.• Body has more than two layers of cells with tissues and
organs. • Body has a through gut with a mouth and anus. • Body has no body cavity. • Has a blood system with blood vessels. • Has a well developed nervous system and a brain. • Has an eversible and retractable ectodermal proboscis.• Reproduction is by asexual fragmentation, or sexual,
when it is normally gonochoristic. • Most species are carnivorous and predatory. • Most are aquatic and marine, there are some terrestrial
and freshwater forms.
Phylum Nemertea
Phylum Nemertea
Ribbon worm
Phylum Rotifera• Bilaterally symmetrical. • Body has more than two cell layers, tissues and organs. • Body cavity is a pseudocoelom. • Body possesses a through gut with an anus. • Body covered in an external layer of chitin called a lorica.• Has a nervous system with a brain and paired nerves. • Has no circulatory or respiratory organs. • Reproduction mostly parthenogenetic, otherwise sexual
and gonochoristic. • Feed on bacteria, and protista, or are parasitic. • All live in aquatic environments either free swimming or
attached
Phylum Rotifera
Phylum NematodaRoundworms
Primitive body cavity
Gut & Anus
No circulatory system
Nervous system
Very successful- well adapted to every ecosystem
Many are parasites500,000? species
Phylum Nematoda
Phylum Mollusca
Class Polyplacophora
Class Gastropoda
Class Bivalvia
Class Cephalopoda
More than 500,000 known species
chitons Snailsnudibranchs
clams SquidOctopusCuttlefishNautilus
Phylum Mollusca
Well developed circulatory system
Nervous system with brain
Some with good eyes
Three main parts:
• Muscular foot- for movement• Visceral mass- contains most of the
internal organs
• Mantle cavity- houses gills
mantle
foot
visceral mass
• Grazers (radula- scraping tongue)
• Filter feeding
• Egg eaters
• Active predation
Class Polyplacophora
Spanish Dancer (nudibranch) & egg mass
Class GastropodaSubclass Opisthobranchia
Cone shell
Triton’s trumpet
Cowery Opihi
periwinkle
Class GastropodaSubclass Prosobranchia
Class Cephalopoda
Day octopus
Class Cephalopoda
Class Cephalopoda
Octopus Intelligence
Mimic octopus from Indonesia
flatfish
lionfish
Sea snake
Blue-ringed octopus
Highly venomous
Phylum Annelida
Class Oligochaeta
Class Polychaeta
Class Hirudinia
earthworm leachesMarine worms
Phylum Annelida
Segmented worms, earthworms, leeches
Marine = polychaetes
True body cavity
Long tubular body
Muscles
9,000 species
Class Oligochaeta
Class Polychaeta
Class Hirudinia
• Segmentation (metameric body plan)• Eucoelomate• 15,000 species• Closed circulatory system, but no heart• Hydrostatic skeleton• Excretion- protonephridia, metanephridia, diffusion or gills• Simple gut• Respiration- diffusion or gills• Central nervous system- brain and nerve cord• Reproduction- asexual or sexual (many gonochoric)• Sensory system of tactile organs, taste buds, statocysts,
photoreceptor cells, and eyes with lenses.
FEEDING MODES- very diverse • Raptors• Herbivores• Browsers/grazers• Omnivores• Direct deposit feeders• Indirect deposit feeders• Suspension feeders
Phylum Arthropoda
Subphylum Trilobitomorpha
SubphylumCheliceriformes
Subphylum Uniramia
Subphylum Crustacea
trilobites spidersticksscorpions
insectscentipedesmillipedes
crabslobstersshrimpbarnacles
Phylogeny of Arthropods
Arthropoda
Worm-likeAncestor
Trilobites(extinct)
Annelids(worms)
Onychophorans(worms w/legs)
Chelicerates(spiders)
Crustaceans(lobsters)
Insects(butterflies)
Insects, crabs, spiders, barnacles
Most species; 80% are insects
Hard chitin exoskeleton (must shed to grow)
Circulatory system with blood, heart
10,000,000? species
Phylum Arthropoda
Subphylum Trilobitomorpha
Extinct Existed: 543-248 mya
Fig. 33-30
SubphylumCheliceriformes
Subphylum Uniramia
Koa Bug
(a) Larva (caterpillar)(b) Pupa
(c) Later-stage pupa (d) Emerging
adult
(e) Adult
Metamorphosis of a Butterfly
Banded coral shrimp
Spiny lobster Hawaiian cleaner shrimpYellow spotted guard crab
Anemone carrying hermit crab
Subphylum Crustacea
Phylum Echinodermata
Class Astroidae
Class Ophiuroidae
Class Echinoidae
Class Holothuroidae
Class Crinoidae
Sea stars Brittle stars
Crinoids
Sea urchins Sea cucumbers
Phylum Echinodermata
No circulatory system
No respiratory system
Excretion (N elimination) by diffusion
Simple nervous system, no brain
Water-vascular system
Sea Star Anatomy
Phylum Echinodermata
Tube feet & associated plumbing
Used for walking, clinging to substrate & holding food
Water Vascular System
Linckia sp.
Acanthaster planci
Class Astroidae
Class Ophiuroidae
Class Crinoidae
Echinometra mathaei
Colobocentrotus atratus
Echinothrix calamaris
Slate pencil urchin
Collector urchin
Class Echinoidae
Holothuria atra
Polyplectana kerfersteninii
Class Holothuroidae
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