The Animal Kingdom

Bio 100

Tri-County Technical College

Pendleton, S. C. 29670

General Features of Animals

• Movement of the entire animal or movement of a part of the animal.

• Heterotrophic mode of nutrition

• Soft Bodies

• Respond quickly and appropriately to changes in their environment

• Sexual reproduction

• Some few animals reproduce asexually and sexually.

• Eucaryotic cells

• No cell walls

• Multicellular forms organized into tissues, organs, and organ systems

Asexual vs. Sexual Reproduction

• Asexual reproduction– some part of the animal body detaches and

grows into an exact duplicate of the parent– no variation

• Sexual reproduction– union of egg and sperm results in an organism

that is similar to parents but not exactly like them

Temperature Regulation

• Ectotherms– body temperature varies– “cold-blooded”– reptiles

• Endotherms– maintain a constant body temperature– “warm-blooded”– mammals

Body Symmetry

• Asymmetry– no regular body form– sponges

• Radial symmetry– “pie” symmetry

• Bilateral symmetry– one plane divides the body into two halves that

are mirror images of each other

Tubular Bodies

• Most animals with bilateral symmetry– body structure composed of 3 layers– tube within a tube– outer tube

• muscles and nerves

– inner tube• digestive system with a mouth at one end and an

anus at the other

Coelomate vs. Acoelomate

• coelom– body cavity between the two tubes

• coelomate animals have a coelom– advanced animals: earthworms, insects,

reptiles, birds, and mammals

• acoelomate, pseudocoelomate– do not have coelom– simple animals: jellyfish and flatworms

Vertebrate vs. Invertebrate

• Invertebrate– don’t have a backbone– invertebrate phyla: Porifera, Cnidaria,

Platyhelminthes, Nematoda, Annelida, Arthropoda, Mollusca, Echinodermata

• Vertebrate– have a back bone (vertebral column– vertebrate phylum: Chordata (Vertebrata)

THE ANIMAL KINGDOM

Phylum Porifera

• the sponges

• water circulates through the body

• marine and freshwater forms

• adults are anchored to something– sessile pattern of existence

• most exhibit radial symmetrical

• no true tissues

Phylum Cnidaria

• hydras, jellyfish, sea anemones, and coral reef

• radial symmetry

• tentacles and stinging cells

• marine mostly

• incomplete digestive tract

Phylum Platyhelminthes

• flatworms--prefix “platy” means flat

• bilateral symmetry

• no body cavity

• incomplete digestive system

• planaria, tapeworms, and flukes

• some cause human disease: tapeworms and flukes

Phylum Nematoda

• roundworms

• cuticle covered body

• pseudocoelom

• complete digestive tract-mouth and anus

• some parasites and some free-living

• pinworm disease in humans

• plant root nematodes

Phylum Mollusca

• muscular foot for locomotion

• many have a calcium carbonate shell

• complete digestive tract

• have a true body cavity

• body is not segmented

• clams, squids, snails

• many use gills for respiration

Phylum Annelida

• segmented worms

• body segmentation

• complete digestive tract

• true body cavity

• bilateral symmetry

• earthworms and leeches

Phylum Arthropoda

• bilateral symmetry

• tough exoskeleton

• segmented: head, thorax, and abdomen

• joint-legged

• insects, spiders, crustaceans, centipedes, and millipedes

• tremendous numbers

Phylum Echinodermata

• spiny-skinned animals

• no body segmentation

• larval stages bilaterally symmetrical

• adults radially symmetrical

• water vascular system--tube feet

• endoskeleton under spiny skin

• starfish and sea urchins

Phylum Chordata

• bilateral symmetry

• segment body with endoskeleton

• well-developed body cavity

• single, dorsal nerve cord

• enlarged anterior end of nerve cord (brain)

• tail at some stage of development

• complete digestive system

Subphylum Vertebrata

• vertebral column to protect spinal cord

• movement by muscles attached to endoskeleton

• complete digestive system with large digestive glands

• ventral heart with 2-4 chambers

• blood with RBC’s and WBC’s

• well-developed body cavity

• paired kidneys with drainage to exterior

• general body plan– head– trunk– 2 pairs of appendages– postanal tail

Classes of Vertebrates

• Class Agnatha -- jawless fishes

• Class Chondrichthyes -- cartilaginous fishes

• Class Osteichthyes -- bony fishes

• Class Amphibia -- amphibians

• Class Reptilia -- reptiles

• Class Aves -- birds

• Class Mammalia: mammals

Class Agnatha

• “Jawless” fish

• Hagfish and lampreys

• Some are parasites that suck the blood out of host

Class Chondrichthyes

• cartilaginous skeleton

• sharks, rays, and skates

Class Osteichthyes

• skeleton made of bone similar to ours

• bony fishes

Class Amphibia

• frogs, newts, and salamanders

• made a partial break from water

Class Reptilia

• turtles, snakes, lizards

• made a complete break from water

• have lungs and water proofed skin

Class Aves

• birds

• only vertebrates with feathers

Class Mammalia

• have hair over most of the body

• have mammary glands that produce milk

• specialized teeth

• feed newborns with milk

• hair modified to spines in some mammals

• 4 chambered heart

Mammals, ctd.

• Monotremes are egg-laying mammals– Duck-bill platypus one of three existing species

– Females do not have nipples

• Marsupials are the pouched mammals– Kangaroos, koalas, opossums

– Deliver offspring that complete development in pouch

• Eutherians (placental mammals…but)– Deliver well-developed offspring