The Sponges – Phylum Porifera

Porifera – the sponges

Porus (pore) + Fera (bearing) Abundant marine grp w 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.

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 thru 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 thru 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

Sponge Sex – ewww!

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.

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.

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! !

Nematocysts

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

tentacles3.Penetrate and anchor in prey and poison

it.

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.

Clown fish live in anemones, and coral

and they’re immune to stings!

Fire Coral and Tube Anemone

Reproductive Characteristics

Asexual reproduction by budding (in polyps)

Sexual reproduction by gametes (in all medusae and some polyps).

Sexual forms monoecious or dioecious; primitive gonads; ciliated free-swimming larva in life cycle of most