The Animal Kingdom

1. The Animal Kingdom

2. Animal Characteristics • Animals are many-celled, eukaryotic organisms that must find and digest food. • Most can move from place to place. • There are 9 animal phyla: • Phylum Porifera—sponges • Phylum Cnidaria—jellyfish, corals, sea anemones • Phylum Platyhelminthes—flatworms • Phylum Nematoda—roundworms • Phylum Annelida—segmented worms • Phylum Mollusca—snails, clams, octopus, squid • Phylum Echinodermata—starfish, sea urchin • Phylum Arthropoda—insects, crabs, spiders • Phylum Chordata—vertebrates

3. Vertebrates and Invertebrates • The first eight phyla in the animal kingdom are invertebrates—animals without backbones. 95% of all animals are invertebrates. • The chordate phylum represents the only group of vertebrates—animals with a backbone and inside skeleton (endoskeleton).

4. Phylum Porifera: Sponges • Characteristics: • Simplest animals. • Porifera means “pore-bearer” in Latin. • Bodies covered with pores and are made of different types of cells but no tissues. • Over 5000 species of all shapes and colors. • All live in water—mostly salt water. • Asymmetrical—no definite shape. • Evolved over 600 million years ago. Sponges don’t wear square pants!!!!

5. Body structure • Hollow, sac-like body with a large opening at the top called an osculum and many small openings on the side called pores. • Sponges are filter-feeders • Water enters through the pores and leaves through the osculum. • Collar cells filter and digest bacteria, algae and protists.

6. Sponges reproduce in two ways: • Asexually—budding or regeneration • Sexually—produce sperm and egg cells. • Sponges are hermaphrodites (produce both sperm and egg cells): However, they cannot fertilize their own eggs. • Sperm cells from one sponge enter another and are taken by amoebocytes to the egg cells. A fertilized egg develops into a free-swimming larva. The larva attaches to a rock and becomes an adult sponge.

7. Sponge Variety Tropical Sponges Commercial sponge

8. Phylum Cnidaria: Jellyfish, Corals, Sea Anemones and Hydra • Characteristics: • Tentacles with stinging cells called, cnidocysts. • “Cnidos” is Greek for “stinging nettle”. • Over 9,000 species ranging in size from microscopic to 70m long. • Live in water—mostly salt water. • Radial symmetry. • Bodies have tissues but no organs. • Feed as predators, killing prey with their stinging tentacles. • Evolved 600 million years ago.

9. The stinging cells (cnidocysts) come equipped with harpoon-like stingers called nematocysts. The stings of some jellyfish can be quite painful, causing reactions ranging from a mild rash to death. The Australian Box Jelly is the most poisonous—killing victims in under 5 min.

10. Australian Box Jellyfish Close-up showing eye spot

11. Wounds from the sting of a box jelly

12. Cnidarians come in two shapes: • Polyp—vase-shaped, sessile cnidarians. • Medusa—umbrella-shaped mobile cnidarians. Medusa Polyp

13. Examples of Cnidarians: • Jellyfish—live as both a polyp and medusa (mostly as a free-swimming medusa). • Reproduce Sexually as sperm and egg cells are released into the water where they unite. • Fertilized eggs develop into a larva that attaches to a rock. • A larva becomes a sessile planula, which grows a mouth and tentacles and is now called a polyp. • The polyp divides into a stack of saucer-like structures that swim away as adult medusas.

14. Hydra—small polyps attached to rocks in freshwater streams and ponds. Can reproduce asexually by budding. • Corals and Sea Anemones—polyps that live attached to rocks on the ocean floor or in large colonies called reefs. Adult hydra with bud Sea anemone Coral Skeletons

15. Coral Reefs • A coral reef is made of billions of skeletons of dead corals that are covered by a layer of living coral polyps. • Largest = Great Barrier Reef of Australia (1200 miles long and 48 miles wide). • Very diverse habitats (home to 35,000 to 60,000 different species). • All are located between 300 N and 300 S latitude.

16. Types of Coral Reefs • Fringing reef—forms close to the shoreline of islands or continents. • Barrier reef—located farther out. Separated from land by a lagoon. • Atoll—formed when fringing reef shrinks—sometimes at the top of a mid-ocean volcano. Fringing reef Atoll Barrier reef

17. Importance of the Coral Reef: • Help protect the shoreline from storms. • Important source of food and shelter for many other marine organisms. • Easily damaged by pollution, careless boaters and careless divers. • Reef balls are used to repair damage reefs.

18. Phylum Platyhelminthes: Flatworms • All have flat, legless bodies with no internal body cavity. • Some are free-living and feed as predators of other small organisms, some are parasites. • All have bilateral symmetry. • Three examples: tapeworms, flukes, and turbellarians.

19. Tapeworms—parasitic flatworms that live in the intestines of a host animal. • Feed on the host’s digested food. • Size: 6-12 meters. • Humans can catch a tapeworm from eating undercooked beef, pork or fish. • Flukes—parasitic flatworms that live inside the bodies of humans and animals. • Shistosoma is a blood fluke found in polluted water. It kills 200 million people a year by blocking arteries of infected people.

20. Turbellarians—free-living flatworms. • Most live in the ocean. • The planarian is a fresh-water turbellarian. It swims using cilia and can reproduce both asexually, by regeneration, and sexually. It has two eyespots on the anterior end that respond to light. Ocean turbellarian Planarian

21. Phylum Nematoda: Roundworms • Long, tapered bodies with a true body cavity between their layers of tissue. • All have a complete, one-way digestive tract. • Most are free-living and feed on organic material in the soil, however, some are serious human parasites. • Reproduce sexually

22. Hookworm • Parasitic roundworms include: • Hookworms—caught by walking barefoot in tropical soil. Larva travel to the intestines, lungs or brain. • Trichina—caught by eating undercooked pork. Causes muscle pain and breathing problems. • Ascaris—caught by eating ascaris eggs found in contaminated food. Worms live in intestines of host. Common in puppies and kittens. Trichina Ascaris

23. Pinworms—caught by ingesting pinworm eggs. Causes an “itchy bum”. It is the most common human intestinal parasite. • Heartworm—roundworm parasite of dogs only. Transmitted by mosquitoes. Easily prevented but difficult to treat once diagnosed. Pinworm Heartworm

24. Phylum Annelida: Segmented Worms • Tube-shaped bodies with segments. • “Annelid” means “little rings”. • Some are free-living and feed on organic material in the soil, saltwater or freshwater. Others are parasites. • Reproduce both asexually as hermaphrodites or by fragmentation; or sexually. • Three classes: marine worms, earthworms, and leeches.

25. Marine Worms—over 6,000 species of segmented worms that live in the ocean. • Move using parapodia • Include: giant tube worms, sand worms, bristle worms, and feather-dusters. • Leeches—external parasites that feed on the blood of a host. • Formerly used in blood-letting. • Currently used in microsurgery.

26. Earthworms—free-living annelids found in the soil. • Have complete body systems: circulatory, respiratory, digestive, nervous, and reproductive.

27. Phylum Mollusca: Snails, Clams, Octopus • All have soft bodies and bilateral symmetry. • The Latin word, “mollis” means “soft”. • Most secret hard, calcium carbonate shells to protect themselves. • Most reproduce sexually • Three basic body parts: • Head: containing the mouth • Muscular foot: for crawling, digging, or swimming. • Visceral mass: location of main body organs. It is surrounded by a layer of tissue called the mantle. The mantle secretes the shell.

28. Classes of mollusks include: • Gastropoda (stomach-foot) —snails, slugs, and sea slugs. They carry one shell (univalve) and live in the water or on land. Most of the world’s most beautiful sea shells are made by gastropods. Some feed on plants, others are predators • Bivalvia—two-shelled mollusks including; clams, oysters, scallops and mussels. Economically important as food and for the production of pearls. All are filter feeders.

29. Cephalopoda (head-foot) —octopus, squid, cuttlefish, and chambered nautilus. Muscular foot is divided into tentacles for swimming. They are very complex and intelligent. Range in size from 1-60 feet. Most are predators of other small invertebrates. Octopus Squid Chambered nautilus

30. Phylum Echinodermata: Seastars • 6,000 species of spiny-skinned animals with radial symmetry. • “Echinoderm” means “spiny-skin”. • Have an internal skeleton made of spines that extend out through the body. • All live in the ocean and reproduce sexually. • Move using a water-vascular system and tube feet. • Most can regenerate lost body parts and can occasionally reproduce this way as a type of asexual reproduction.

31. Examples of echinoderms: • Sea stars and brittle stars: have 5 or more arms lined with tube feet. Feed as predators on clams by inserting their stomach into the clam and digesting it inside the shell. • Sea urchins and sand dollars: do not have arms. Covered with movable spines used for defense and movement. Most feed as grazers on plants and algae. • Sea cucumbers: leathery skin with no spines. Expels its internal organs to confuse predators. Also feed as grazers on plants.

32. Phylum Arthropoda: Jointed Legs • Characteristics: • Largest group of animals with over 1 million species known. That number may be as high as 10 million. • Jointed appendages (legs, antenna, pinchers and claws) • Segmented bodies • Exoskeleton made of chitin. Must be shed from time to time in a process called molting. • Open circulatory system • Dorsal heart and ventral nervous system. • Most reproduces sexually • Five classes: Arachnida, Crustacea, Chilopoda, Diplopoda, Insecta

33. Arachnids: spiders, scorpions, mites and ticks. • Most have two body regions: abdomen and cephalothorax. Simple eyes and 4 pair of legs attached to the cephalothorax Poison glands, fangs or stingers to capture prey.

34. Spiders are found everywhere. They spin webs using spinnerets in their abdomen. • Scorpions are found in tropical areas and hunt insects and spiders. • Ticks are external parasites that feed on the blood of a host. Some transmit Lyme disease and Rocky Mountain Spotted Fever. • Mites are found mostly in dust and are harmless.

35. Crustaceans: crabs, lobsters, crayfish, shrimp and pill bugs. • Most have two body regions: cephalothorax and abdomen. • Five pairs of appendages including large pinchers on most. • Most have two pair of antenna

36. Chilopoda: centipedes • Long, flat bodies with one pair of legs per body segment. • Carnivores: eat snails, slugs and worms and can bite humans. • Diplopoda: millipedes • Long, rounded bodies with two pairs of legs per body segment. • Plant eaters: will not bite humans

37. Insects: largest group of arthropods • Three body segments: head, thorax and abdomen. • Three pairs of legs attached to the thorax. • One pair of antenna. • Some have one or two pairs of wings; some have no wings. • Large, compound eyes; some also have simple eyes. • Open circulatory system. • Two types of metamorphosis: Incomplete and Complete.

38. Stages of Incomplete Metamorphosis: • Egg, Nymph, Adult • Stages of Complete Metamorphosis: • Egg, Larva, Pupa, Adult

39. Phylum Chordata: Vertebrates • All chordates have the following three characteristics at some time in their lives: • Notochord: soft, flexible rod of cartilage. It develops into the vertebrae in most chordates. • Nerve cord: develops into the brain and spinal cord. • Gill slits: paired openings in the throat. Develop into gills in some chordates. • All reproduce sexually • Feed as either herbivores, carnivores, or omnivores • Most chordates are also known as vertebrates.

40. Agnatha: Jawless fish: They have eel- like bodies and sucker-shaped mouths. They are external parasites of other fish. Ex: Lamprey and Hagfish • Seven classes of vertebrates: Chondrichthyes: Cartilage fish: Skeletons made of cartilage only. They have uncovered gills and no swim bladder Ex: Sharks, skates and rays

41. Osteichthyes: Bony fish: Skeletons made of bone. All have Covered gills and swim bladders. Includes 95% of all fish. Ex: lungfish, lobe-finned fish, and ray-finned fish Amphibia: Amphibians: Live a double-life: larva (tadpole) that breaths through gills and adult that breaths through lungs. Most have moist, smooth skin. All must lay eggs in water. Ex: frogs, toads, salamanders and newts. Reptilia: Reptiles First animals to lay amniotic eggs. All have dry-scaly skin. All breath through lungs. First truly successful land animals. Ex: turtles and tortoises, alligators and crocs, snakes and lizards.

42. Aves: Birds Endothermic (warm blooded) animals with a body temp. of 104-108o. All have feathers, thin-hollow bones, 4-chambered hearts, and specialized body systems to make them capable of flight. They lay amniotic eggs in groups called clutches. Ex: eagle, chicken, parrot, robin Mammalia: Mammals Endothermic animals with hair or blubber to keep warm. All have a 4-chambered heart and a diaphragm to assist in breathing. All produce milk from mammary glands to feed their young. Includes over 20 different orders. Ex; egg-laying mammals, marsupials, and placental mammals (including humans).