What is an Animal Chapter 24 Animal Movie

What is an Animal? Chapter 24 Animal Movie (15 min)

24 -1 Animal Characteristics • • Eukaryotic Multicellular Heterotrophic Mobile at some stage

Support • Support – Invertebrates – lack backbones • May have external skeleton- exoskeleton • May have internal skeleton – endoskeleton – Vertebrates – have backbones & endoskeleton

Animal Development • Most have Sexual Reproduction • Egg + Sperm = Fertilization – Can be internal or external fertilization – Forms a single celled zygote – Undergoes cell division during cleavage to form two cells – Hermaphrodites – have both male and female reproductive parts

Cell Division • Once it is two cells, now called an embryo • Cells keep dividing to form a hollow ball called a blastula • Cells begin to fold inward to form a gastrula, this forms an outer layer (ectoderm) and an inner layer (endoderm) • Ectoderm develops into skin and nervous tissue • Endoderm develops into digestive track and organs associated with digestion

Cell Division

Gastrulation

Tissue Development • Endoderm – inner layer that develops into digestive organs and the lining of digestive tract • Mesoderm - middle layer that develops into muscles, circulatory system, excretory system, and in some respiratory system • Ectoderm – outer layer that develops into nervous tissue and skin • Sea Urchin - Blastula

Germ Layer Development

24 -2 Animal Body Plans

See Page 699!

Symmetry View of the left side of a bilaterally symmetrical animal. Drawing by John Norton.

Symmetry • Asymmetry – no symmetry – Ex. Sponges

Radial Symmetry • Radial – can be divided along any plane through a central axis – Examples: Hydra and Jellyfish

Bilateral Symmetry • Bilateral – can be divided down its length into mirror images • Examples: Humans and dogs

Body Plans • Acoelomate – has three body layers, but no cavity • Example – Flatworm

Acoelomate

Pseudocoelomate • Pseudocoelomate – have three body layers, with a fluid-filled body cavity between the endoderm and mesoderm layers • Example: Roundworms

Pseudocoelomate

Coelomate • Coelomate – have three body layers, with a fluid-filled body cavity within the mesoderm layer • Examples – earthworms, insects, fish

Coelomate

Protostome vs. Deuterostome • Protostome animals develop the mouth first – Examples include earthworms and insects • Deuterostome animals develop the anus first – Examples include echinoderms and vertebrates

Chapter 24. 3 Sponges, Cnidarians

Phylum Porifera Sponges: • Invertebrates • Sponges can live to be 100+ years old. Yellow Tube Sponge

Porifera Body Structure • Asymmetrical • No Tissues (ecto-, endo-, mesoderm) • Just two layers of cells with a jelly-like substance in between • Porus

Porifera Body Structure • Pore cells: These surround the pores on the outside of the sponge. The pores are where water and food enter the sponge • Epithelial cells: These are the outer ‘skin’ of a sponge. These cells can contract to close the pores, if needed • Collar cells: These line the inside of the sponge. These cells have flagella that cause the current of water

Sponge Anatomy http: //lcmrschooldistrict. com/roth/Biology_animate/Ch 26/Active. Art/

Porifera Body Strurcture Spicules: Between sponge cells – Not cells – Make up the ‘skeleton’ support system – Sponge structure video - sponge movie

Porifera Support • Archaeocytes cells – Can move and change shape – Involved in digestion – Make egg and sperm – Make spicules (small needle-like structures)

Porifera Support • Some freshwater sponges can produce gemmules, a seedlike unit that can survive cold temperatures. • Spicules provide support. – Can be sharp (made of calcium carbonate matter) – Can be made out of silica – Can be more flexible (like the fibrous protein spongin)

Porifera Motility • Larvae: Free-swimming • Adult Sponge: sessile, usually on the sea floor

Porifera Feeding and Digestion • Filter feeder - food particles pass through the pores. - Particles cling to cells - Cells digest food individually.

• finger or eyed sponge • bright yellow sponge

Porifera Reproduction • Sexually – Most sponges are hermaphrodites, have both sexes, which help insure fertilization with sessile animals. – Most sponges are fertilized internally. – Sperm that is carried by water currents. – The larvae can swim for a few days until they attach to a surface. • Asexually – fragmentation – budding

3 Classes/Types of Sponges • Demospongiae – spongin • Calcarea – calcium • Hexactinellida – silica

Sponge Review System Type Sponges System Muscular-Skeletal A sponge is a hollow tube with many pores or openings. The skeleton is made of calcium carbonate, silicon or spongin spicules. Digestion A sponge takes in food via the water that flows through the pores. Nervous A sponge has a very low level reaction to the world around it and does not have a brain per se. Circulation A sponge has water flow in through the pores. The water contains the food and oxygen the sponge needs. Respiration A sponge takes in water through its pores, and then canals that move the water all throughout the sponge. Then the oxygen from the water is used. Reproduction A sponge reproduces by budding, fragmentation and also sexually. Excretion A sponge has carbon dioxide and other wastes removed as the water moves in and out through the pores. Symmetry A sponge is asymmetrical or has radial symmetry. Coloration A sponge is white, red, orange, green, yellow, brown, purple, black

Cnidarians Jellyfish and Sea Anemones

Jellyfish

Cnidarian Features • Mostly marine organisms • Radial symmetry • Two cell layers with only one body opening • Tissues made of ectoderm and endoderm • Simple nervous system called the nerve net • Obtain oxygen by diffusion

New Scyphozoan Jellyfish Discovered (May 2003) Tiburonia granrojo (Big Red) was taken during a remotely operated vehicle (ROV) dive on the Gumdrop Seamount off the coast of California. Can be up to 1 m in diameter. Lives between 650 -1500 m deep.

Sea Anemones Coral Polyps

Cnidarian Digestion • Cnidocytes – Stinging cells on tentacles that capture prey – Comprised of nematocysts • • A capsule A coiled, threadlike tube Poison Barbs, sharp enough to penetrate a crab shell

It only takes 3/1000 ths of a second for the nematocyst to discharge

Cnidarian Reproduction • Asexual is through budding • Sexual reproduction is through fertilization of eggs and sperm • Can be internal or external fertilization

Cnidarian Reproduction Two life stages of Cnidaria: 1. Medusa- floating 2. Polyp- sessile

Life Cycle of a Jellyfish

Cnidarian Classes/Types Class Hydrozoa • Have both the polyp and medusa stages of life • Can form colonies • Two kinds: 1. Hydroids – hydra 2. Siphonophores – colonies of hydra ex. Portuguese Man of War

Colony of Hydra

Siphonophores

Portuguese Man of War A Violet Snail eating a siphonophore

Cnidaria Types Class Scyphozoa- (jellyfish) • Transparent • Medusa is dominant • Some jellyfish have fatal stings.

Cnidaria Types Class Anthozoa • Polyp stage is dominant • Live in colonies • Build protective calcium shelters • Symbiotic with a photosynthetic protist • Use tentacles to feed 1. Corals- live in colonies 2. Sea Anemone-Live individually

the phylum of stinging animals video http: //www. lophelia. org/movies_reefs. htm movie on coral reef

Mutualistic Cnidaria • Crab + Sea anemone= sea anemone grows on crab’s shell to protect crab and collect food scraps

Commensalism Cnidaria • Clown fish + Sea anemone = Anemone stings predators of clown fish but not the clown fish

Human Bone Surgery • Coral contains Hydroxyapatite which has the same composition as human bone. • The coral can be grafted onto human bones during: – Face reconstruction – Jaw reconstruction – Arm and leg surgery Knee Surgery

Ctenophora • Comb jellies – are jelly-like with radial symmetrical bodies • They have no stinging cells with which to stun their prey, but they are voracious filter feeders • Eight rows of combs made of cilia for motion • Reminds me of the movie – The Abyss

Characteristics of Ctenophora 1. Radial symmetry 2. Multicellular, few tissues, some organs and organelles. 3. Body contains an internal cavity, a mouth, and anal pores. 4. Swims by means of plates of cilia (the combs) 5. Reproduction mostly sexual as hermaphrodites, occasionally asexual. 6. Has a well developed nerve net. 7. Has a distinct larval stage which is planktonic. 8. Lives in marine environments. 9. All are carnivorous.

Colloblasts – Sticky threads used in prey capture

Data Analysis Lab Page 714