The Animal KingdomWhat are the factors that define an animal?• Animals are multicellular organisms.• Their cells lack a cell wall.• Animals cells are organized into complex organ-systems • Animals are heterotrophic - they must obtain carbon and energy by eating other organisms and absorbing the consumed organisms nourishment.• Animals require oxygen (for aerobic respiration)• Animals can either reproduce sexually or asexually (most are sexual).• Animal life cycles require a period of embryonic development.• Animals are typically mobile

PhylumEach Phylum has at least one characteristic that sets it apart from the others. This ppt will cover Porifera and Cnidaria

Porifera (sponges) – spicules

Cnidaria (nahy-dair-ee-uh)(hydra & jellyfish) nematocysts

Platyhelminthes (flatworms)

Annelida (oligochaetes/leeches)

Gastrotricha (gastrotrichs)

Nematoda (nematodes)

Mollusca (snails/bivalves)

Arthropoda (arthropods)

Major Aquatic Invertebrate Taxa

Monoecious

Diecious

Coelom

Mesoderm

Terms

Having both male and female reproductive organs; hermaphrodite

Having only one type of reproductive organ; separate and distinct sexes

A body cavity lined with a mesoderm

Middle layer of germ where organs will rise

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Phylum Porifera

From the Latin porus for pore and ferre to bear

Animal with pores

Phylum Porifera

About 5,000 species worldwide

About 25 species are freshwater

A Osculum-

B Collar cell or choanocyte-

C Amebocytes-

D Incurrent pores-

where the water leaves the sponge system

These cells are “totipotent”. They can change into all of the other types of cells. Ingest and digest food caught by choanocyte collars.

Where water enters the sponge

Vase-shaped cells with a collar of fibrils. Strains out the smallest food items from the water such as individual bacteria. A single flagellum extends and beats, driving the water currents that keep the sponge alive and healthy.

E Spicules-

F Mesenchyme-

G Covering cells or pinacocytes-

Importance to man:

A 10 cm sponge can filter 20 Liters of water a day; many animals live within the cavities of sponges

‘skin cells’, thin, leathery and tightly packed.

acellular gel layer between the outer and inner cell layers

non-living aggregates of a chemical nature, secreted and made from silica, calcium carbonate, or a protein matrix called spongin.

Common name SpongePhylum Porifera

Body PlanOrganization

LevelCell-level; not yet at tissues

Symmetry None; some radialCephalization NoneBody Cavity None

Segmentation None

Internal Systems

Movement Sessile, choanocytes do beat

Support Spicules

Body Covering Pinacocytes

Nutrition Filter feeder, bacteria, plankton, debris

Respiration Diffusion:(CO2) and (O2) from H2O

CirculationH2O moves through pores, Amoebocytes

transport O2 and food

Excretion Diffusion to H2O

Nervous None

Reproduction

Asexual – budding, fragmentation, gemmules

Sexual – amoebocytes make sperm and ova at different times.

ReproductionReproductionAll sponges can reproduce sexually

Generally monoecious and produce eggs and sperm at different times to prevent self-fertilization

Produce flagellated larva that exit via osculum

Larval motility is the principal dispersal mechanism

Larvae attach to substrate and begin growing

Sponges have great powers of regeneration

FeedingSponges feed on fine particulate material in the inflowing water.

Food particles generally range from 5- to 50 µm and are phagocytized by amoebocytes.

After digestion is complete, the wastes are expelled into the water.

Phylum CnidariaPhylum Cnidaria

Major Aquatic Invertebrate Taxa

PhylumPorifera (sponges)

CnidariaCnidaria (hydra & jellyfish) (hydra & jellyfish)

Platyhelminthes (flatworms)

Annelida (oligochaetes/leeches)

Gastropoda (gastropods)

Nematoda (nematodes)

Mollusca (snails/bivalves)

Arthropoda (arthropods)

Phylum Cnidaria

Over 10,000 species

Class Hydrozoa (only freshwater representatives)only 16 freshwater species, the rest of the 10,000 belong to Scyphozoa and Anthozoa

Class Scyphozoa (jellyfishes)Class Anthozoa (sea anemones and corals)

Cnidaria ClassificationCnidaria ClassificationKingdom AnimaliaPhylum Cnidaria

Class HydrozoaHydraPortuguese Man’o War

Class ScythozoaTrue jellyfish

Class AnthozoaCoralSea anemone

Hydra and JelliesHydra and Jellies

GastrodermisGastrovascular cavity

Mesoglea

Epidermis

Tentacle Tentacle

Mouth

Mouth

Hydra’s Three Hydra’s Three Cell Layers Cell Layers

A.Gastrovascular cavity

open space in interior of hydra

B. Gastrodermis circular muscle filaments, enzymatic

gland cells, neurons, and sensory cells

C. Mesoglea layer connecting gastrodermis and

epidermis

D. Nematocysts cells within cnidocysts that discharge a

toxic, sticky, or barbed filament; hydra is usually toxic

E. Epidermis

epithelial cells, nematocysts, sensory cells, germs cells, neurons

Common name Hydra HydraPhylum Cnidaria

Body PlanOrganization

LevelTissues

Symmetry RadialCephalization NoneBody Cavity None

Segmentation None

Internal Systems

Movement Sessile, locomotion by gliding or somersault

Support Hydrostatic (water exerting pressure)

Body Covering Epidermal cells

NutritionCarnivores. Protozoans, shrimp, water

fleas (Daphnia)

Respiration Diffusion:(CO2) and (O2) from H2O

Circulation Diffusion through epidermis

Excretion Diffusion through cells

Nervous Nerve net with cnidocytes

ReproductionAsexual – buddingSexual – Hermaphrodites; some dioecious

Cnidocytes Nematocysts

polyp medusa

Dimorphism in Cnidaria

This structure is an example of Budding!

Body Plan in AnimalsBody Plan in Animals

CoelomPronunciation: Coe-lom

(See-lum)

Body Cavity PlanBody Cavity Plan

Acoelomate

ectodermto gut

No body cavity presentOrgans are in direct contact with the epithelium Tissues hold organs in place Ex. Flatworms

endoderm

mesoderm

PseudocoelomatePossesses a coelom, but it is lined only on the body wall - not around the gut. Does not possess vascular systems or skeletons. Ex. Nematodes or roundworms mesoderm

ectoderm gut

pseudocoel

endoderm

Body Cavity PlanBody Cavity PlanCoelomPossesses a coelom in which both

the inside of the body wall and the gut is lined by mesoderm

Tissues called mesenteries suspend organs in the coelom and keep them in place.

Earthworms and higher animals