Animal Kingdom

Phylum Porifera

Phylum Cnidaria

Biology 112

Phylum Porifera (sponges)

Phylum Porifera – SPONGES

There are about 10,000 species of the phylum Porifera (sponges), all of which are aquatic or marine

Only phylum in the subkingdom Parazoa (multicellular / not very specialized!)

Sponges are the simplest of multi-cellular animals

Sponges…

Sponge bodies are very diverse in form

Most are asymmetrical

Do not have a mesoderm

No organs, can produce toxins

A sponge is a bottom-dwelling creature which attaches itself to something solid in a place where it can, hopefully, receive enough food to grow. (larval stage is motile)

Sponges…

The scientific term for sponges is Porifera which literally means "pore-bearing."

A sponge is covered with tiny pores, called ostia, which lead internally to a system of canals and eventually out to one or more larger holes, called oscula

Sponges… In canals of sponges are specialized

choanocytes, commonly known as collar cells. They are sticky, funnel shapes with flagellum.

Functions of choanocytes (collar cells):1. Beating flagellum forces water into the

sponge (bringing nutrients and oxygen & carrying out waste

2. sticky collars of the collar cells pick up tiny bits of food brought in with the water

Sponges..

Another type of cell is an archaeocyte, also called an amebocyte, takes the food to other cells within the sponge

How do you think these cells move?

Amebocytes are very effective feeders eating a wide size range of food particles and transport digested food throughout the sponge.

Sponge Skeletons

The skeleton is made of tiny needle like splinters called spicules (hard), a mesh of protein called spongin (soft), or a combination of both!

Your bath sponge is actually dried skeletons composed of the protein material spongin. (The living remains of the sponge is gone)

Cross Section of a Sponge:

Sponge filtering - http://www.youtube.com/watch?v=T7E1rq7zHLc&feature=fvw

Sponge Sex….

Most are hermaphroditic, but produce only one type of gamete per spawn.Asexually – regenerationSexually – sperm and eggs

The sperm is released into the water column by the "male" sponge and finds its way to the "female" sponges, where fertilization occurs internally

Ecological Importance

Provide habitats for marine animals such as snails, shrimp, and shrimp

Spicules can redirect sunlight to photosynthetic organisms below

Phylum Cnidaria (jellyfish, coral and other stingers…)

Phylum Cnidaria

Class Scyphozoa (cup animals)Jellyfish

Class HydrozoaHydras

Class Anthozoa (flower animals)Sea Anemones, Coral

Phylum Cnidarian

There are about 10,000 species of the phylum Cnidaria, almost all of which are marine. (less than 50 are freshwater)

They represent the next highest level of organization in animals

They possess true tissues

Most radially symmetric

Soft-bodied

Carnivorous animals that have stinging tentacles.

Cnidarians…

The name Cnidaria comes from the Greek word "cnidos," which means stinging nettle.

Cnidaria have cnidocytes, stinging cells located on along tentacles.

Each cnidocyte contains a nematocyst, a poison filled structure that has a coiled dart.

Cnidocytes are arranged around their mouths

Casually touching many cnidarians will make it clear how they got their name when their nematocysts eject barbed threads tipped with poison.

Cnidarians…

They are diploblastic, meaning they develop from two embryonic germ layers, endoderm and ectoderm.

The layer in the middle is a jellylike layer called a mesoglea

Life Stages of Cnidarian

Two different types of life cycles

Polyp is usually sessile

Medusa is motile

Two Basic Body Forms of Cnidaria

Cnidarians…

Reproduction• Most cnidarians reproduce both sexually and

asexually.

• Polyps can reproduce asexually by budding.

• In most cnidarians, sexual reproduction takes place with external fertilization. External fertilization takes place outside the female's and male’s body.

Class Hydrozoa Portuguese man o’ war

Varadero, Cuba

Class Hydrozoa Portuguese man o’ war

National Geographic - http://www.youtube.com/watch?v=RBdCpcapB0s

Brought up on the beach by wind.