Presentation on theme: "INVERTEBRATE DIVERSITY. Animal diversity is very intense! Blue-ringed octopus – one of the deadliest animals in the ocean. Lives in shallow reefs and."— Presentation transcript:
Animal diversity is very intense! Blue-ringed octopus – one of the deadliest animals in the ocean. Lives in shallow reefs and tide pools from Japan to Australia.
Octopi are incredibly intelligent. They are masters of disguise, using camouflage as a defense mechanism. The blue-ringed octopus injects poison into its prey or into the vicinity of its prey. It also uses a different substance for self-defense that is 10,000 times more lethal than cyanide.
MIMIC OCTOPUS Can look like a venomous sea snake, a toxic flatfish, a sea anemone, or a jellyfish! Only a mimic octopus can mimic multiple toxic animals.
Animal cells lack cell walls that provide support to plants and fungi. Animals are held together by extracellular proteins. Most have muscle cells for movement and nerve cells for conducting impulses.
Most animals are diploid and reproduce sexually. Egg and sperm are the only haploid cells. (Ants, bees, and wasps have some males that develop from unfertilized eggs that are haploid)
Sperm and egg join to form a zygote. The zygote develops into a multicellular adult. The zygote divides repeatedly in half until there is a ball of cells called a blastula. One side of the ball of cells folds inwards forming a gastrula.
If the gastrula becomes an anus, the animal is a deuterostome (echinoderms and chordates). A mouth develops from a second opening later. If the gastrula becomes a mouth, the animal is a protostome.
Larva After gastrulation, many animals develop directly into adults. Others develop into one or more larva stages first. Larva undergo metamorphosis (major body change) in developing into an sexually reproducing adult.
Animals have been around for roughly a billion years. The fossil record shows a giant explosion of animal diversity in the Cambrian era (approx. 542 million years ago).
THERE IS NO “ONE” BEST ANIMAL Each form, each adaptation, and each body plan has advantages and disadvantages.
Phylogeny The evolutionary history of animals (where they come from). The phylums are on the far right. The branch points indicate a common ancestor between the two branches.
Animal body plans vary in symmetry, body cavity, and number of germ layers.
First branch: true tissues or no true tissues. If there are no true tissues, then the animal is a sponge. If there are true tissues, then the animal is a eumetazoan.
Next Division – Body Symmetry Radial SymmetryBilateral Symmetry
Radial Symmetry Example: Sea Anemone No matter where you cut through it, it will be the same on either side. Exampe: Cnidarians.
Radial Symmetry The animal has a top and a bottom but lacks front and back or right and left sides. Radial animals are sedentary or passive drifting.
Bilateral Symmetry If you cut the organism down the middle, there is a definite right side and a definite left side.
Bilateral Symmetry These animals have mirror-image right and left sides, a distinct head and tail, and a back (dorsal) and belly (ventral) surface. They also have a brain, sense organs and mouth located in the head. Facilitates mobility; the animals meets its environment head-first.
What does the gastrula become? If the gastrula becomes an anus, the animal is a deuterostome. If the gastrula becomes a mouth, the animal is a protostome.
Tissues Outer Layer – Ectoderm These are the outer coverings that become your skin or in some organisms becomes nerves and the brain
Endoderm The endoderm is in the middle and becomes the linings of the organs.
Mesoderm The mesoderm becomes the muscle and bones.
Animals body plans vary in organization of tissues.
Phylum Porifera means “pores” water moves through the pores flagella on the Inside driving he water through which is full of particulates. Purple Tube Sponge
Porifera - Sponges Sponges lack true tissues. In other animals, cell layers formed during gastrulation give rise to tissues and organs. Some animals have only ectoderm and endoderm, but most animals also have mesoderm.
Flatworms Example: Planaria Have simple eyespots. Mouth is located on their stomach. Can cut their head in half and it will generate two heads.
Tapeworms Tapeworm parasites are found in beef and pork and other animals. Tapeworm infections in humans are caused by eating raw or undercooked infected meat. The tapeworm larva develops in the human intestine and can grow up to 12 feet.
Tapeworm (cont’d) Scolex on the anterior end to attach to their host. They do not have a “true” digestive system. They absorb nutrients through their flat-bodied skin. THEY CAN BE DOZENS OF FEET LONG.
Nematode Worms Longitudinal muscles Over 500,000 species, many are parasitic. They have a true digestive system. Example: Heartworms in dogs.
Nematodes parasitic on Humans Ascarids (roundworms) Hookworms Pinworms
Molluscs All have a muscular foot. All have a visceral mass containing most of the internal organs. Their mantle may secrete a shell to enclose the visceral mass.
Gastropods – largest groups of mollusks and include snails and slugs.
Most snails are protected by a single, spiral shell. In land snails, the lining of the mantle cavity functions as a lung. Slugs have lost their mantel and shell and have long colorful projections that function as gills.