For dissection purposes, the anatomical directions of the body must be known:

• Anterior: toward the head or top– Also called cranial

• Posterior: opposite the head, toward the tail/anus– Also called Caudal

• Ventral: at the front of, in front • Dorsal: behind, in the back of• Lateral: away from the center

of the body

Details of Phyla

• Fill in the defining characteristics into your chart– Specialization- are cells specialized for different

jobs?– Symmetry- is it radial or bilateral? Is there

symmetry at all?– Body Cavity- do they have a true coelom?

Pseudocoelom? No body cavity at all?– Protostome/Deuterostome- does the blastopore

become the mouth or the anus?

Details of Phyla

• Fill in the defining characteristics into your chart– Digestion- Do they digest inside the cells or

outside the cells? How many openings does the digestive tract have?

– Segmentation- are there divisions along the body specialized for different purposes?

– Skeleton- internal, external, or hydrostatic?– Examples- what do animals in this phylum look

like?

Skeleton- do you mean like bones?

• Skeleton refers to a support system- remember that animals do not have cell walls- so what holds animals into shape and prevents them from being a giant blob of cells?

• Hydrostatic skeleton- fluid pressing against muscles, no hard parts

• External skeleton- tough outer covering of chitin• Internal skeleton- this is what YOU have- internal HARD

substances like BONES

Phylum Porifera• Cell Specialization:

Yes (few)

• Symmetry: None (asymmetrical)

• Body Cavity: No Digestive Tract

• Protostome or Deuterostome: N/A

Phylum Porifera

• Digestion: Filter feeder Intracellular

• Segmentation: No

• Skeleton: Silica

• Example: Sponges

Phylum Porifera• Respiration, Circulation, and

Excretion:– occur via diffusion of gases and

wastes between water and cells

• Reproduction:– asexual (budding) or sexual

(internal fertilization)

• Response– Produce toxins to ward off

predators (sea slugs)

Phylum Cnidaria• Cell Specialization: Yes

• Symmetry: Radial

• Body Cavity: Gastro-vascular cavity (one opening) for feedingand gas exchange

• Protostome or Deuterostome: N/A

Phylum Cnidaria

• Digestion: Extracellular in the Gastrovascular cavity

• Segmentation: No

• Skeleton: Hydrostatic (two muscle layers and fluid)

• Examples: Jellyfish, coral, Portuguese man of war

Phylum Cnidaria• Respiration, Circulation, and Excretion:

– occur via diffusion of gases and wastes between water and cells, or cell to cell

• Reproduction:– Asexual (budding) or sexual (external fertilization)

• Response:– Nerve net– Stinging cells called cnidocytes on tentacles

Ctenophora• Cell Specialization: Yes

• Symmetry: Radial

• Body Cavity: Gastro-vascular cavity with 2 openings:mouth and anal pore

• Protostome or Deuterostome: N/A

Ctenophora• Digestion: Extracellular in the

Gastrovascular cavity

• Segmentation: No

• Skeleton: Hydrostatic (two muscle layers and fluid)

• Examples: Jellyfish, coral, Portuguese man of war

Ctenophora• Respiration, Circulation, and Excretion:– occur via diffusion of gases and wastes between water and

cells

• Reproduction:– hermaphroditic

• Response:– Nerve net– No stinging cells, but have sticky cells called colloblasts

used to capture prey– bioluminescent

Phylum Platyhelminthes

• Cell Specialization: Yes

• Symmetry: Bilateral

• Body Cavity: Acoelomate (have a digestive tract but no body cavity)

• Protostome or Deuterostome: Protostome

Phylum Platyhelminthes• Digestion: Extracellular in the

gastrovascular cavity one opening- mouth/anus

• Segmentation: No

• Skeleton: Hydrostatic

• Examples: Tapeworms, Flukes

Phylum Platyhelminthes• Respiration, circulation and excretion:

– Diffusion exchanges gas and excretes waste through body walls

• Response:– Ganglia in head region (groups of nerve cells)– Eyespots (detect light)

• Reproduction:– Sexual

• Hermaphrodites (produce both egg and sperm cells)• Two worms can exchange sperm

– Asexual• fission

Rotifera• Cell Specialization: Yes

• Symmetry: Bilateral

• Body Cavity: Pseudocoelomate(lined partially with mesoderm)

• Protostome or Deuterostome: Protostome

Cilia covered corona

Rotifera

• Digestion: Extracellular

• Segmentation: No

• Skeleton: Hydrostatic

• Example: rotifers (seenin your pond water lab)

Rotifera

• Parthenogenetic reproduction (eggs are diploid) and only in certain conditions are males formed.

• Males are formedfrom unfertilized haploid eggs– Fertilize other

haploid eggs and create a dormant fertilized eggthat under the right conditions will become a parthenogenetic female.

Phylum Nematoda

• Cell Specialization: Yes

• Symmetry: Bilateral

• Body Cavity: Pseudocoelomate(lined partially with mesoderm)

• Protostome or Deuterostome: Protostome

Phylum Nematoda• Digestion: Extracellular

• Segmentation: No

• Skeleton: Hydrostatic

• Example: Hookworms, Filarial worms, pinworms, heartworms

Phylum Nematoda• Respiration, circulation and excretion:– Diffusion transports nutrients and gases– Flame cells remove excess water from the body

• Response:– Several ganglia in head region (groups of nerve cells)– Several nerve extend the length of the body

• Reproduction:– Sexual: separate sexes, internal fertilization

Phylum Annelida• Cell Specialization: Yes

• Symmetry: Bilateral

• Body Cavity: Coelomate(lined with mesoderm)

• Protostome or Deuterostome: Protostome

Phylum Annelida• Digestion: Extracellular

• Segmentation: Yes

• Skeleton: Hydrostatic

• Example: Leeches, earthworms, meal worms

Phylum Annelida• Respiration, circulation and excretion:

– Breathe using gills (aquatic) or use diffusion (terrestrial)– Closed circulatory system– Nephridia are specialized excretory organs that filter fluid

• Response:– Brain and several nerve cords– Sensory tentacles, chemical receptors

• Reproduction:– Sexual: separate sexes, external fertilization– Some annelids are hermaphrodites

Mollusca

• Cell Specialization: Yes

• Symmetry: Bilateral

• Body Cavity: Coelomate

• Protostome or Deuterostome: Protostome

Mollusca

• Digestion: Extracellular

• Segmentation: Yes

• Skeleton: Hydrostatic

• Examples: Snails, clams, squids, octopi

Phylum Mollusca• Respiration, circulation and excretion:

– Breathe using gills (aquatic) or use diffusion (terrestrial)– Open circulatory system– Nephridia are specialized excretory organs that filter fluid

• Response:– Simple nervous system (small ganglia, few nerve cords, simple

sense organs) (ex: clams)– Well-developed brains (ex: octopi)

• Reproduction:– Sexual:

• external or internal fertilization• Hermaphrodites or separate sexes

Phylum Arthropoda

• Cell Specialization: Yes

• Symmetry: Bilateral

• Body Cavity: Coelomate

• Protostome or Deuterostome: Protostome

Phylum Arthropoda

• Digestion: Extracellular

• Segmentation: Yes

• Skeleton: Exoskeleton

• Examples: Crustaceans, Arachnids, Insects

Phylum Arthropoda• Respiration, circulation and excretion:

– Trachael tubes or book lungs– Open circulatory system– Malphigian tubules extract waste from the blood and add it to

digestive waste

• Response:– Several ganglia in head region (groups of nerve cells)– Several nerve extend the length of the body

• Reproduction:– Sexual: separate sexes, internal fertilization

Phylum Echinodermata

• Cell Specialization: Yes

• Symmetry: Radial

• Body Cavity: Coelomate

• Protostome or Deuterostome: Deuterostome

Phylum Echinodermata • Digestion: Extracellular

• Segmentation: Yes

• Skeleton: Endoskeleton

• Examples: Sea stars, Brittle stars, sand dollars

Phylum Echinodermata• Respiration, circulation and excretion:– Diffusion through tube feet– Circulation through water vascular system

• Response:– Nerve ring that surrounds the mouth has radial nerves that

connect to body sections

• Reproduction:– Sexual: separate sexes, external fertilization

Phylum Chordata• Cell Specialization: Yes

• Symmetry: Bilateral

• Body Cavity: Coelomate

• Protostome or Deuterostome: Deuterostome

• Digestion: Extracellular

• Segmentation: Yes

• Skeleton: Endoskeleton

• Example: Lancelet, sea squirts

Nonvertebrate chordates

• Cell Specialization: Yes

• Symmetry: Bilateral

• Body Cavity: Coelomate

• Protostome or Deuterostome: Deuterostome

Nonvertebrate Chordata • Digestion: Extracellular

• Segmentation: Yes

• Skeleton: Endoskeleton

• Example: Lancelet, sea squirts