Review of the Animal Kingdom

Identify and define the two major divisions of the Animal Kingdom:

Invertebrates – animals that lack a backbone

Vertebrates – animals that have a backbone

List four general characteristics of the Kingdom Animalia:

Multicellular Eukaryotic Heterotrophic Cells lack cell walls

Name and describe four evolutionary trends in the Kingdom Animalia:

1) cell specialization and levels of organization – specialized cells, tissues, early development

2) body symmetry – asymmetry, radial, bilateral symmetry

3) cephalization – concentration of sense organs at the anterior of body

4) body cavity formation – fluid-filled space for internal organs

List and define seven essential functions in animals:

1) feeding 2) respiration 3) circulation 4) excretion 5) response 6) movement 7) reproduction

The Sponges – Phylum Porifera

Porifera – the sponges

Porus (pore) + Fera (bearing) Abundant marine group with some fresh water (f.w.) species. Can range in size from small crusts or growths or simple vases few mm high to 1-2 meters. Sponges are multicellular,

heterotrophic, have no cell walls, and contain a few specialized cells

ClassificationKingdom Animalia (animals)Phylum Porifera (sponges)Classes: 1. Calcarea (calcerous sponges - having spicules)

2. Demosponginae (horn sponges, like the bath sponge)

3. Scleropongiae (coralline or tropical reef sponges)

4. Hexactinellida (glass sponges).

Definition Porifera are asymmetrical or radially

symmetrical animals without1. Organs, mouth, digestive system or

nervous tissue. 2. Their bodies are porous, with canals

and chambers through which a water current flows,

3. One to many internal cavities lined with choanocytes.

Symmetry Explained

Bilateral Symmetry - Right side of body is mirror image of the left side

Radial Symmetry - One slide (like pie) is the mirror image of another slice.

 ASymmetry

Asymmetry. No slice through the body will divide it into two like halves. Most sponges. Asymmetrical animals are plant-like and display irregular growth.

Radial Symmetry Radial symmetry. The body has the

general form of a short or tall cylinder with one main longitudinal axis around and along which parts are arranged.

Any plane through this longitudinal axis divides the body into 2 like halves.

Examples: Some of the sponges which are vase-shaped, the Cnidaria and the echinoderms.

Bilateral Symmetry

 Bilateral symmetry. one plane of symmetry which divides an animal into left and right halves which are comparatively the same.

Most animals.

More Defining Characters

No mouth organs, systems, digestive tract, anus, nerve cells.

Surface perforated by numerous pores. Incurrent openings are small and

numerous Excurrent - few and large

More Defining Characters

Internal cavities. Interior is hollow or permeated by

numerous channels. Some or all interior spaces are lined

by specialized cells called choanocytes.

Sponge Anatomy 101

Feeding Sponges are filter feeders that sift

microscopic food particles from the water

Digestion is intracellular (takes place inside cells)

Choanocytes trap and engulf food from water passing through the sponge, then archaeocytes complete the digestive process

Respiration, Circulation, and Excretion

Sponges rely on water being passed through its body cavity for respiration, circulation, and excretion

Oxygen from the water diffuses into the cells of the sponge body, and ammonia and other wastes diffuse from the body into the water

Response

Sponges don’t have nervous systems

They can produce toxins to protect them from potential predators

Reproduction Sponges can reproduce asexually and

sexually Sexual reproduction:

A single sponge produces egg and sperm, each released at different times

Eggs produced by one sponge is carried through the water to another sponge and fertilized in the sponge’s body internal fertilization

Fertilization zygote larva (immature stage)

Sponge Reproduction…

Reproduction (cont’d)

Asexual reproduction: Sponges can reproduce asexually by:

Budding – part of sponge breaks off of the parent and grows into a new sponge on the sea floor

Sponges can produce gemmules – groups of archeocytes surrounded by spicules; gemmules can survive harsh conditions and grow into a new sponge in favorable conditions

Cool Stuff – Regeneration! Tremendous ability to repair and

restore lost parts. Can also reconstitute selves if

totally disintegrated. Sponge tissue has some similarity

to human connective tissue. Could lead to aid in tissue transplantation.

Importance of Sponges

1. Reefs provide habitat for many animals

2. Vacuums of the sea -- clean up the sea floor/oceans

3. Sponges are a commercial venture4. Several medicinal compounds,

including antibiotics, antivirual drugs, and drugs for leukemia come from sponges.

Cnidarians

Jellyfish, Corals Anemones and Hydroids

Cnidarians eat by stinging

their prey so it becomes

paralyzed, and then they bring the food into their stomach.

Cnidarians eat mussels, fish, plankton, and worms.

Phylum Cnidaria1. Soft bodied animals with stinging tentacles

arranged in circles around the mouth2. Radial Symmetry3. Specialized cells and tissues, including nervous

sys4. Lifecycles often include two different stages:

polyp and medusa5. 3 Body layers: Ectoderm, Mesoderm, Endoderm6. Nematocysts – stingers7. Only one internal cavity, the digestive cavity,

with a mouth, but no anus.

Cnidarians

Definition: Cnidarians are soft-bodied, carnivorous

animals that have stinging tentacles arranged in circles around their mouths

Have body symmetry and specialized tissues

Name comes from cnidocytes, or stinging cells, found in their tentacles.

Body Plan

Cnidarians are radially symmetrical Have a life cycle that includes 2

different—looking stages: a polyp and a medusa

Life Cycle & Polymorphism Two basic

types of individuals: polyps and medusae.

Dominance of Medusa or Polyp lifecycle varies species to species.

Polyp = adapted for sedentary or sessile life. Tubular body w/ mouth at one end surrounded by tentacles.

May live singly or in colonies.

Polyp Stage of Life Cycle

Colonial polyps

Medusa Medusa = jellyfish form, free swimming and

sexually mature form, bell-shaped or umbrella-shaped bodies, radial symmetry mouth centered on concave side, tentacles and one

or more types of sense organs borne on rim of umbrella.

Medusa provides dispersal mechanism so don't compete with parents. Mesoglea much thicker than in polyp - constitutes bulk of animal - makes it buoyant = "jelly" of jellyfish.

Medusa

CNIDARIANS have no bones, are hollow with 3 layers of cells.

They live in salt or fresh water.

When a cnidarian reproduces, the young hatch into the mother stomach, then, She spits them out.

Feeding Inside the cnidocytes of the tentacles

are nematocysts, poison-filled stinging structure with a dart, that can sense prey, then release the dart into the prey, paralyzing/killing them

Prey is then taken into the cnidarian’s gastrovascular cavity, a digestive chamber with one opening

Digestion is extracellular (takes place outside of cells)

Nematocysts

1.Hold prey2.Sticky -- aid in locomotion by attaching

tentacles3.Penetrate and anchor in prey and poison

it.

Nematocysts video:

Nematocysts firing:http://www.youtube.com/watch?v=6zJiBc_N1Zk&feature=related

Nematocysts can be Pretty

Nematocyst poison Most dangerous to man is Cubozoan jellyfish,

the sea wasp (Chironex fleckeri).   Caused more human suffering and death off Australian coasts than Physalia (Portuguese man-of-war) has in any of its home waters.

Symptoms range from:1. burning pain at site of contact 2. lesions and eruptions of various sorts, often

severe enough to leave scars, 3. great pain, fever, and respiratory

interference.4. severe reactions due to shock & allergies 5. "Sting" of most is imperceptible to humans.

Problems usually occur only when repeatedly stung.

Respiration, Circulation, and Excretion

Nutrients transported throughout body by diffusion

Respiration and excretion also by diffusion through body walls

Response Cnidarians have specialized sensory cells Nerve net – a loosely organized network

of nerve cells that allow the organism to detect stimuli Nerve net usually distributed evenly

throughout the body, but in some cases are concentrated around the mouth or in rings

Statocysts – sensory cells that determine direction of gravity

Ocelli, or eyespots, that detect light

Movement

Different ways of moving Hydrostatic skeleton – circular and

longitudinal muscles (sea anemones) Jet propulsion – muscles contract,

pushing water out and the organism forward (medusas)

Reproduction

Asexual – budding Sexual

External fertilization – female cnidarian releases eggs into water, male cnidarian releases sperm fertilization in water zygote free-swimming larva polyp medusa

Video:

Sea anemone reproductionhttp://www.youtube.com/watch?v=u8LGZaezpV8&feature=related

Classification of Cnidarians Classes: Scyphozoa, Cubozoa

and Anthozoa

1. Jellyfishes (Classes Scyphozoa and Cubozoa) are predominantly medusae w/ polyp stage very reduced or completely absent.

2. Corals and anemones (Class Anthozoa) are entirely polyps, no medusa.

The Portuguese Man o War wasn’t just a Ship

Physalia from Jamaica

Portuguese Man O

War

A tenacious hunter with a taste for

fish and the poison to

render most prey

helpless

Yikes!

           

Portuguese Man 'O War   

Physalia physaliaSize: to 1 ft (float) and 50 ft (tentacles)Habitat: floats at the surfaceNotes: dangerousFortunately, this creature, with its powerful battery of stinging tentacles, is more common in bays and protected waters than in the open ocean. The sting of the Man'O'War can vary from extremely painful to incapacitating to fatal, depending on the severity and the victim's reaction.

When a cnidarian reproduces, the young

hatch into the mother’s

stomach, then, she spits them

out

Jellyfish sting to defend themselves.

The Man of War is poisonous to humans.

Other Dangerous Jellyfish

           

Moon Jellyfish / Red Jellyfish ( Lion's Mane )   

 Aurelia aurita / Cyanea capillata

Habitat: anywhereNotes: Jellyfishes are free-swimming relatives of  corals, anemones, and hydroids. In fact, in many cases they are the same animal, just in a different stage of life ! Not all medusas ( as jellyfishes are called ) have a corresponding polyp stage, and likewise not all polyps have a corresponding medusa stage, but most conform to this life cycle. Small jellies ( up to 1" across ) are most likely the medusa stage of some hydroid, while large jellies are usually the dominant stage of a species in which the polyp stage is almost absent.Translucent Moon Jellies are harmless and quite common. Red Jellies have a painful wasp-like sting, but are usually much less common. And try as you might to avoid it, sooner or later every northern diver will get a stray tentacle draped across the face and lips - the only places exposed to attack.

Moon Jellyfish

Beached Moon Jellies: the surf has stripped away all the tentacles, leaving just a harmless dying blob of goo.

Red or Lion's Mane

Jelly

Avoid these.

Swim away – swim away

NOW! !

Clown fish live in anemones, and coral and they’re immune to stings!

Fire Coral and Tube Anemone

Videos!

Jellyfish:http://www.youtube.com/watch?v=HqfCm58SB6Yhttp://www.youtube.com/watch?v=pCVADKwqwnc