The Kingdom Animalia The movers and shakers Part I: Introduction to animals and the phyla Porifera and Cnidaria. Gulo gulo

What are animals? Animials are multicellular, eukaryotic heterotrophs. Animals are very responsive to their environment. All animals are capable of locomotion at some point in their lifecycle. Falco peregrinis

How do they move? All animals, at least during some point in their lifecycle possess contractile fibers. In higher animals, these contractile fibers are called muscles. All muscles are capable of doing is shortening and then relaxing.

The phyla of the Kingdom Animalia There are nine phyla in the Kingdom Animalia. Each phyla contains animals which share many characteristics with each other. 8 of the phyla are considered invertebrates (this means that a they lack a backbone. The 9th phylum are animals with a backbone.

The nine phyla of Kingdom Animalia 1. Porifera 2. Cnidaria 3. Platyhelminthes 4. Nematoda 5. Annelida 6. Arthropoda 7. Mollusca 8. Echinodermata 9. Chordata

Phylum Porifera Members of this phylum are commonly referred to as the sponges. Over 5,000 species, mostly marine but some live in fresh water. The very simplest of animals. As adults they are sessile, asymetrical filter-feeders

I thought all animals moved? Adult sponges don’t move, but as larvae they do. The larvae can swim around. Eventually they attach themselves to the ocean bottom and metamorphose into their adult form.

Reproduction Sponges are capable of sexual and asexual reproduction. In sexual reproduction a sperm cells swims to an egg cell and produces a motile larvae. Sponges can also reproduce by budding, when a piece of a sponge breaks off and skips the larval stage all together.

Cell layers Sponges only have two layers of cells (germ layers). Food is taken in by each individual cell. This limitation puts a size restraint on a sponge.

Feeding in Porifera Porifera feed by pumping water through it’s body and filtering out nutrients. The water is pumped by means of flagella which line the interior of the sponge. Oxygen is absorbed and wastes excreted during this process.

Phylum Cnidaria The second phylum are represented by such animals as Jellyfish and corals.

The Cnidarians Over 9,000 species, all of them are aquatic. Jellyfish are found in all of the worlds seas from the equator to the poles. Corals live in warm shallow waters only. Sea anenomies are marine predators which have stings like jellyfish. Hydra are small fresh water cnidarians.

Cnidarian body plan Cnidarians display radial symmetry. They have a central mouth surrounded by numerous tentacles that extend outward from the body. The simple digestive cavity is a two-way tract. Any materials which cannot be digested are passed out of the body through the mouth.

Jellyfish stings A characteristic of jellyfish that allows them to subdue and kill their prey are called nematocysts. Each nematocyst contains a small vesicle filled with toxins, an inner filament and an external sensory hair. When the hair is touched, it mechanically triggers the cell explosion, a harpoon-like structure which attaches to organisms that trigger it, and injects a dose of poison in the flesh of the aggressor or prey

Dangerous Jellies While most jellyfish stings are painful, only a few are considered life-threatening. Box Jellies and Irukanji, both found in Austrailian waters are the most dangerous. http://video.google.com/videosearch?client=safari&rls=en-us&q=jellyfish&oe=UTF-8um=1&ie=UTF-8&sa=N&hl=en&tab=wv

Jellyfish types There are several different families of Jellyfish. Some, like the portugese man-o-war do not swim, but float by means of a bladder that acts like a sail. Other jellyfish actively swim through the oceans.

Corals Corals reproduce sexually as both sperm and eggs are released into the surrounding water. Larval corals are free swimming organisms. They attach themselves to rock on the ocean bottom and metamorphose into adults.

Marine ecosystems Corals play a very important role in maintaining biodiversity. Coral reefs support some of the most diverse communities of plants and animals on earth. Rising water temperatures have a negative impact on coral reefs.