NAME Per March 25, 2013

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1 NAME Per March 25, Approximately what percentage of animals are invertebrates? Approximately 97 percent of all animals are vertebrates. 2. What are invertebrates?invertebrates are animals which do not have a backbone. 3. Name the phyla of invertebrates and members of each phyla.there are nine phyla of invertebrates:porifera, Cnidaria, Platyhelminthes, Nematoda, Rotifera, Mollusca, Annelida, Arthropoda, and Echinodermata. Sponges 4. Sponges are in the phylum Porifera. There are about 800 different species and most of these are marine organisms found in oceans and seas. A few sponges are found in freshwater, but these are small and not brightly colored. 5. Sponges are filter feeders that trap food (plankton) from water as it flows through them. 6. Sponges have no basic body arrangement and are said to be asymmetrical. 7. Sponges live attached to one spot as adults so they are sessile. 8. The skeleton of sponges is made of a flexible protein called spongin and hard fibers called spicules which are composed of calcium carbonate or silicon dioxide. 9. Sponges are full of holes called pores through which water flows into their hollow bodies. 10. Sponges are the simplest animals and lack the tissue level of specialization like all other animals. Sponges do have some specialized cells in their bodies. 11. Special cells called choanocytes line the pores and have flagellum that spin to pull in water. 12. Collar cells at the base of choanocytes capture plankton from the water and start digesting it. 13. Amebocytes are special cells that carry this food to all other parts of the sponge. 14. Wastes and excess water leave a sponge through a large opening at the top called the osculum. 15. Sponges reproduce asexually by internal or external buds and by fragmentation whenever a piece of a sponge breaks off. This last method helps sponges form colonies. 1

2 16. Sponges reproduce sexually also and are hemaphrodites producing both eggs and sperm. Sponges exchange sperm with each other and do not fertilize their own eggs. 17. Internal buds or gemmules form if the freshwater supply evaporates and are release when the sponge dies and become active when freshwater returns. Cnidarians 17. The phylum Cnidaria includes what organisms? The phylum of Cnidaria includes sea anemones, hydra, corals and jellyfish 18. All cnidarians are marine organisms except for the hydra which is found in freshwater. 19. Cnidarians all have radial symmetry and tentacles or arms that have stinging cells called nematocysts or cnidocytes. These stinging cells shoot out like a harpoon and contain a poison (toxin) that can kill or paralyze their prey. 20. Cnidarians have two body layers; an inner gastrodermis and an outer epidermis. 21. Cnidarians have one opening into their hollow bodies called the mouth so food enters and wastes leave through this same opening. This is called a two-way digestive system. 22. The hollow cavity the mouth opens into is called the gastrovascular cavity (GVC). 23. Cnidarians have two body forms. Polyp forms have the mouth and tentacles located at the top like Hydra, corals, and sea anemones. Medusa forms like the jellyfish have their tentacles and mouth located at the bottom. 24. Some cnidarians like the jellyfish go through both polyp and medusa forms in their life cycle. 25. Cnidarians have a simple nerve net and can reproduce both asexually by budding and sexually by producing fertilized eggs whenever males release sperm and females release eggs into the water. 26. Corals build limestone cases that make underwater reefs. Flatworms 27. Flatworms are in the phylum Platyhelminthes and are flattened dorsoventrally with bilateral symmetry. 28. Flatworms are said to be acoelomate because of their solid body. 29. Flukes and tapeworms are parasitic flatworms having only one body opening called the mouth. 2

3 30. Specialized flame cells remove wastes. 31. The planarian is the most common free living flatworm. It is found in water or moist places. 32. Planarians produce both eggs and sperm and are said to be hermaphrodites; however, they exchange sperm with other planarians. Planarians also reproduce asexually by fragmentation 33. Flukes and tapeworms usually live in their host's digestive tract resistant to digestive enzymes of the host. allowing the host to digest their food. 34. Tapeworms are divided into sections called proglottids with complete reproductive structures which produce fertilized eggs. The head is called the scolex and has both hookers and suckers to attach to the host. 35. Tapeworms are hermaprhodites and fertilize their own eggs which pass out of the host's body in ripe proglottids along with feces. 36. Humans get tapeworms from eating infected, undercooked pork, beef. or fish, while children pick up tapeworm eggs from the feces found in cat litter boxes. 3 Nematodes 37. Roundworms are in the phylum Nematoda and are cylindrical in shape and tapered at both ends. 38. Roundworms are pseudocoelomate because their body cavity or pseudocel is not fully lined. The body cavity is filled with fluid giving them a hydrostatic skeleton against which muscles can contract. 39. Roundworms have a complete gut with both a mouth and an anus giving them a one-way digestive tract digestive tract. 40. Roundworms have no blood and no heart but can digest food. Nutrients are distributed by a non-blood fluid which is not pumped. 41. Most roundworms are parasites with bilateral symmetry and no segments (i.e., unsegmented). They are found in all habitats. 42. A protective cuticle covers them and must be. 43. Roundworms reproduce sexually. 44. The roundworm called Trichinella causes the disease trichinosis and is picked up when someone eats infected, undercooked pork. This disease affects the heart and skeletal muscles. 45. The roundworm Ascaris parasitizes human lungs. Hookworms and pinworms are common parasites of humans, and the Filaria worm attacks the lymphatic system causing great swelling.

4 Rotifers 46. Rotifers are microscopic worms found in terrestrial and aquatic habitats. 47. Rotifers have a crown of cilia surrounding their mouth for movement and feeding. Their bodies are covered with an external layer of chitin. 48. Rotifers have separate sexes, but some species reproduce by parthenogenesis. 49. Describe parthenogenesis. Parthenogenesis is reproduction without fertilization: a form of reproductionin which a female gamete develops into a new individual without fertilization by a male gamete Mollusks 50. Name several organisms in the phylum Mollusca. The phylum Mollusca contains snails and slugs, bivalves, octopus, squid, and the chambered nautilus. 51.Mollusks have a durable shell made of limestone and are found in all habitats. 52. List several economic importance's of this group. The economic advantages of this group include: sources for human food, pearl and shell production, crop and flower damage, destruction to submerged wooden structures, and intermediate hosts for some parasitic diseases. 53. Name the two largest invertebrates. The two largest invertebrates are the giant squid and the giant clam. 54. Mollusks have bilateral symmetry and a visceral mass containing their body organs. Mollusks also have a muscular foot for movement which can be modified into arms or tentacles. 55. Mollusks breathe through gills or lungs located below a protective layer called the mantle. This layer can also form an external shell. 56. The radula is a rough tongue for scraping food. 57. Mollusks have a three-chambered heart and an open-flowing circulatory system (Exception: octopus and squid) 58. Mollusks reproduce sexually and go through a free swimming larval stage called the trochopore. 4

5 59. Gastropod mollusks have a muscular foot on their belly and include the shelled snail and the unshelled slug. 60. Bi-valved (Bivalvia) mollusks have a two part hinged shell that is opened and closed by adductor muscles. They move by jet propulsion or by extending their muscular foot, and they respire through siphons. 61. Name some bivalve mollusks. Bi-valve Mollusks include: clams, oysters, mussels, and scallops 62. Cephalopod mollusks are head-foot mollusks that have a beaks and jaws, arms or tentacles, and use their siphons to move by jet propulsion. 63. Name some cephalopod mollusks. Cephalopod mollusks include: the octopus, squid and nautilus 64. What is the only shelled cephalopod? The nautilus is the only cephalopod mollusk with an external shell. 65. Cephalopods breathe through gills. 66. Cephalopods are the most intelligent mollusks. 67. The octopus and squid can secrete an inky substance into the water to escape predators and have an internal shell. The giant squid is the largest cephalopod. 68. Annelids are segmented worms found in all habitats. Annelids 69. External segments correspond to internal segments called septa. (External segments are characterized by ringlike structures called metameres along the body, and corresponding internal segments are called septa.) 70. Give two ways that segmentation is an advantage for an organism. Segmentation gives worms more flexibility in movement. If one segment is damaged, it isn't usually fatal to the animal because their organs are duplicated in other segments. 71. Annelids have a tube within a tube body plan called the coelom where the body organs are located. This tube runs from the mouth to the anus and is fully lined. 72. Annelids show cephalization by having bilateral symmetry with an anterior head where most sense organs are found. 73. Coelomic fluid gives annelids a hydrostatic skeleton. 74. The best known member of this group is the earthworm which moves by external bristles called setae on each body segment. These bristles are made of chitin. Earthworms respire through their moist skin and have a closed circulatory system and five pairs of hearts oraortic arches. 5

6 75. Describe how an earthworm feeds and tell how this helps the environment. Earthworms feed on decomposing vegetation causing it to decompose faster. A pharynx sucks in the organic debris which the muscular gizzard grinds. Earthworms bring the nutrients from the subsoil to the top soil, thereby helping plants to grow. 76. What are castings and where can they be found? Castings are undigested materials and they left outside the earthworm burrow. 77. Leeches are annelids with suckers at both the anterior and posterior end.anterior suckers are used to suck blood from the host, while posterior suckers help to latch on to the host. 78. Most leeches are scavengers or predators, but blood sucking leeches are collected for anticoagulant. 79. Both leeches and earthworms produce eggs and sperm and are called hermaphrodites; however, leeches lack setae and are flattened dorsoventrally. 80. Polychaetes are marine annelids whose setae are modified into paddle like parapodia for movement and more area for gas exchange. 81. Polychaetes live commensally with what other organisms? Polychaetes often live commensally with sponges, mollusks, echinoderms, and crustaceans. 82. Arthropod means jointed appendages. 83. Give 5 characteristics of all arthropods. Arthropods have these characteristics: Arthropods a. hard exoskeleton which is usually composed of substance called chitin b. go through periodic ecdysis (molting) as they shed or molt their exoskeleton c. they have specialized body segments (head, thorax, cephalothorax, & abdomen) d. jointed appendages such as legs, antenna, and mouthparts. e. open circulatory system (blood is pumped out of blood vessels into the body) 84. What is ecdysis and why is it necessary? Ecdysis is the shedding or regular molting of an outer layer by arthropods such as insects and crustaceans. Ecdysis is necessary because as the arthropod grows it needs more room in the exoskeleton and sheds the small shell in order to grow a larger size. 6

7 85. What is the exoskeleton of arthropods composed of? The exoskeleton of arthropods is composed of chitin. 86. What is meant by an open circulatory system? An open-circulatory system is when blood is pumped out of blood vessels into the body 87. Arthropods are divided on the type of appendages they have. Chelicerata have chelicerae or fangs and no antenna. Crustaceans have pincers called chelipeds, and Mandibulata have mandibles or jaws. 88. Trilobita are extinct, marine arthropods with ahead and segmented trunk with a pair of legs on each section. 89. Terrestrial arthropods like insects, centipedes, and millipedes breathe through hollow air tubes called trachae;aquatic chelicerates like the horseshoe crab have book gills to breathe; spiders, ticks, and scorpions use book lungs to get air; and crustaceans breathe through gills. 90. Terrestrial mandibulates are uniraimous with one-branched appendages; while aquatic crustaceans are biraimous with two-branched appendages. 91. Arthropods have a nervous system with an anterior brain and sensory organs that include compound eyes or simple eyes called ocelli; tympanic membranes for hearing; and antenna for smelling, feeling, or tasting. 92. Malpighian tubules filter nitrogen wastes in arthropods. 93. The subphylum Chelicerarta contains the class Xiphosura with the horseshoe Crab and the class Arachnida with spiders, ticks, scorpions, and mites. Both classes have body regions, the cephalothorax and abdomen, no antenna, 4 pairs of walking legs, and chelicera or fangs. 94. Appendages on the head of chelicerates called pedipalps are used for sensing the environment and getting food into the mouth. 95. Spiders have posterior glands called spinnerets that help make their silken webs to get prey. Spiders detect movement whenever their prey gets caught in their webs and by sensory hairs on their body. Spiders produce poison to kill their prey and are beneficial because they feed mainly on insects. 96. Spiders are unlike insects in that they have eight legs not six legs, only simple eyes and not compound, and two body regions(cephalothorax and abdomen) and not three (head, thorax, and abdomen). 97. Name the body regions of insects and spiders. 98. The black widow and brown recluse are two poisonous spiders in our area. 99. The class Crustacea is in the subphylum mandibulata and includes crabs, shrimp, lobster, crayfish, and barnacles and the terrestrial pillbugs and sowbugs Crustaceans have a pair of sensory antenna and a pair of shorter attennules for balance. The head also contains three types of mouthparts -mandibules, maxilla, and maxillipeds. They also have pincers called chelipeds to help catch and eat food. 7

8 101. Aquatic crustaceans have an external shell or carapace that must be molted, and they are used by man for food The class Chilopoda contains predators called centipedes with fangs, venom glands, posterior pincers, and a single pairs of legs per body segment The class Dilopoda contains millipedes which are vegitarians (herbivores) with two pairs of legs per body segment The largest and most successful group of arthropods are the insects Insects have three body regions, six legs, a pair of sensory antenna, and a pair of wings for flight. Termites and silverfish are wingless insects, while flies have their second pair of wings modified into balancing organs called halteres Insects have 4 mouthparts which include the jaw or mandible, the maxilla, the lower lip or labia, and the upper lip or labrum Insect mouthparts are modified according to their food source. Butterflies have siphoning mouthparts, flies have spongy mouthparts, mosquitoes have sucking mouthparts, and grasshoppers have chewing mouthparts Wings and legs are both attached to the midsection or thorax on insects, and some female insects have an egg laying tube or ovipositor on the end of their abdomen Name two ways insects communicate. Insects communicate by producing sounds and by making chemicals called pheromones Insects detect sound by tymphanic membranes on the abdomen and sensory sensory that cover their body Spiracles along the abdomen of insects open into their breathing tubes or trachea Insects with complete metamorphosis go through egg, larva, pupa, and adult stages; while those with incomplete metamorphosis go through egg, nymph, and adult stages Give examples of insects with complete and incomplete metamorphosis. Butterflies, bees, flies, and beetles go through complete metamorphosis, while dragonflies and grasshoppers go through incomplete metamorphosis. Insects such as silverfish and fleas do not go through metamorphosis Hormones control metamorphosis (and molting). Echinoderms 115. Give some examples of echinoderms. The phylum Echinodermata include the starfish, sea urchins and sea cucumbers 8

9 116. What does echinoderm mean? The echinoderm means spiny skin Why are echinoderms considered to be the most advanced invertebrates? Echinoderms are the most advanced invertebrates because all other invertebrates are protostomes in which the blastopore (first opening in embryo) in their development becomes the mouth while Echinoderms are deuterostomes in which the blastopore becomes the anus. Echinoderms have an endoskeleton composed of movable or fixed calcium plates called ossicles. The members of this phylum have radial symmetry with a five part body plan (pentaradial). Adults have no head or brain and move by extendable tube feet. Echinoderms also possess a water vascular system made up of a system of canals that help the organism feed and move All invertebrates, except echinoderms, are considered to be deuterosomes because their blastopore becomes their anus Echinoderms have an endoskeleton made of movable or fixed calcium plates called ossicles, radial symmetry with a five part part body plan (pentaradial), no head or brain as adults, and extendable tube feet for movement Echinoderms have a water vascular system composed of canals. Water enters a pore called the madreporite and goes through a short stone canal to the ring canal. radial canals connect to the ring canal and determine the five part body plan How do starfish use their water vascular system when feeding? Starfish consume clams by turning their stomach inside out and sticking it into the clam shell to digest the clam. Their hydraulic water system is strong enough to help starfish open clam shells Skin gills are used for respiration and waste removal Echinoderms reproduce asexually by fragmentation or sexually with external fertilization Starfish are in the class Asteroidea and are active marine predators with five arms attached to a central disk. Their mouth is located on the underside or oral surface. Bivalve mollusks are favorite food of starfish. They can eject their stomach into the clam and digest it Sea Urchins and sand dollars are in the class Echinoidea and they lack distinct arms. They do have five rows of protruding tube feet which they use along with external skeleton for movement. Triangular teeth around the mouth help them scrape or crush their food. They graze on algae, coral, and dead fish The class Crinoidea contains sea lilies and feather stars Crinoids have upright, highly branching arms around their mouth which they use for filter feeding. Sea lilies are attached by a stalk, while feather stars are able to detach and move about Brittle stars are in the class Ophiuroidea and have slender arms that easily break off to escape predators Holothuroidea contains sea cucumbers that are soft, slug-like marine creatures with leathery outer skin. They usually lie on their sides and can eject part of their intestines to scare away predators. They move with tube feet or by wiggling their entire body. Some of these are hermaphroditic which is unusual for echinoderms. 9

10 Level of Organization Cellular- Each cell is essentially an independent, self-sufficient unit that can perform all of the functions needed to sustain the organism and reproduce. Example: Unicellular organisms Tissue- Multicellular organisms that have groups of cells that act together to do special jobs. Example: cnidarians Organ Multicellular organisms that have their tissues organized in to structures known as organs that carry out specific functions. Organ Systems Multicellular organisms that have their organs organized to act together to perform various functions. Example: molluscs Individual/Colonial/Both Individual- Each organism essentially is an independent, self-sufficient unit that can perform all of the functions needed to sustain itself and reproduce. Example: Jellies, flatworms, tube worms, snails, lobster, people Colonial Group of organisms of the same species that share tissues and that share resources (such as food) and jobs (such as defense). Example: Portuguese Man of War, some corals, some anemones Modes of Feeding (How Animals Eat) Suspension Feeders- Suspended food particles (bacteria, phytoplankton, zooplankton, or detritus) are removed from the surrounding water by using a capture or filtering mechanism. Deposit Feeders- Nutrients are obtained from the sediments of soft bottom habitats such as sand. Quantities of sediment are swallowed, organic material is digested, and the remaining material is passed along as waste. Example: sea cucumber Grazer- Organisms search and harvest live plant and algal material. Example: sea urchins, some snails, parrotfish Absorption- Digestion may occur outside of the body; the products of digestion are then absorbed either through specialized organs, or across the body wall. Example: sea stars. Predation- The organism, or predator, eats another animal or prey. Example: squid, octopus, lumpy claw crab, fireworm, sea star, sharks, sea otter, dolphin Scavenging- The organism feeds on dead organic matter. Example: hermit crab, fiddler crab, some brittlestars Symmetry Spherical symmetry the simplest form of symmetry, body is spherical in shape and has no polarity (a clear definition which allows one to determine which side is up or down), lacks a clear axis line. Example: certain Protozoa Asymmetrical having no symmetry, lacking an axis, and having no specific shape. Example: sponges. Bilateral symmetry having a right and left side which are mirror images of one another. Example: flatworms Radial symmetry shaped like a cylinder with body parts arranged equally in every direction around it; an axis line will divide the body like a cake. Radial symmetry can be further classified according to the number of planes the organism can be divided with. They include: a) Biradial symmetry portions of the body are specialized, two planes divide the animal into similar halves. Example: sea anemones. b) Pentameral symmetry (also referred to as pentamerous radial symmetry) having the basic radial body plan with five additional appendages. Example: most sea stars. c) Multiradial symmetry having the basic radial plan with numerous arms. Example: Sun stars such as Heliaster (sea stars with multiple arms). 10