Today's Class: Animal Classification Invertebrates CONTENTS • • • • • • • • Sponges Cnidarians Flatworms Roundworms Segmented Worms Mollusks Echinoderms Arthropods Invertebrates (animals without backbones) • make up roughly 97% of all animals on Earth, while vertebrates make up only 3% • thrives in all kinds of environment • may be free-living or parasitic Sponges Cnidarians Flatworms Roundworms Segmented Worms Invertebrates (animals without backbones) • some are so small that they cannot be seen with the naked eye, while some are larger than most animals • diverse and comes in all forms, sizes, shapes, colors and roles in ecosystem Echinoderms Arthropods Mollusks Sponge Sponges • called as poriferans • have pores or openings all over the their bodies • mostly marine animals, few can be found in freshwater Invertebrates (animals without backbones) Sponge Sponges • simple animals and are sessile • have spicules, made of hard minerals that provide the sponges with rigidity and protection Invertebrates (animals without backbones) Sponge Sponges • sponges that do not have spicules are supported by a network of tough fibers • not productive hunters, but filter feeders • collar cells obtain food • water leaves through osculum Invertebrates (animals without backbones) Cnidarians • known as coelenterates • there are over 10,000 kinds of these • mostly found in in oceans, few are found in freshwater Invertebrates (animals without backbones) Jellyfish Jellyfish Cnidarians • classified into three groups: hydras, jellyfishes, corals and sea anemones • corals live in colonies • secrete a skeleton made of limestone that becomes coral reefs Invertebrates (animals without backbones) Cnidarians • have stinging cells called nematocysts • cells are barbed threads tipped with poison • have 6-10 tentacles surrounding the mouth that help in capturing food Invertebrates (animals without backbones) Cnidarians • they lack anus, waste are discharged through the same opening Invertebrates (animals without backbones) Flatworms • also called as platyhelminthes • have flat and ribbonlike bodies • do not have body cavities that contain developed circulatory or respiratory organs Inertebrates (animals without backbones) Planari a Flatworms • instead, they absorb oxygen and nutrients via diffusion • digestive cavity has only one opening for taking in food and excreting waste, so digestion does not continuously happen Inertebrates (animals without backbones) Flatworms • most known among flatworms are parasitic ones (tapeworms, flukes) • tapeworm's body is a series of segments (proglottids) • hermaphroditic • get nourishment from their host Inertebrates (animals without backbones) Flatworms • planaria - nonparasitic flatworms • found in lakes and ponds • feed on small organisms (dead or alive) • able to regenerate lost parts of their bodies Inertebrates (animals without backbones) Ascaris Roundwoms • called as nematodes • have long, smooth, rounded bodies that have bristles, rings, ridges • found in water. soil, in plants, other animals • most are big to be seen Invertebrates (animals without backbones) Ascaris Roundwoms • first organisms to have digestive system • mouth - take food, anus excrete wastes • passage of food is aided by the worm's wavelike movement Invertebrates (animals without backbones) Ascaris Roundwoms • some are parasitic to humans (hookworms, pinworms, Ascaris, filarial worms, Trichina worms) • Ascaris, hookworms, and pinworms can enter stomach and intestine and cause damage Invertebrates (animals without backbones) Ascaris Roundwoms • Trichina worms infest tongue and diaphragm causing injury to humans • filarial worms can infest the body and make legs and feet swell known as elephantiasis Invertebrates (animals without backbones) Segmented Worms • called annelids • have long, segmented bodies • bodies allow them to burrow into the soil or swim in water easily • can be found on land, freshwater, and saltwater Invertebrates (animals without backbones) Annelids Segmented Worms • their body are identical • have developed digestive and open circulatory system • breathe through the skin • example: earthworm - lives under rocks or burrow into soil; useful in maintaining aeration and hydration of soil Invertebrates (animals without backbones) Segmented Worms • some live in other plants or animals like leeches • attached themselves and feed on host's blood through their suckers • sometimes used in medicine to lessen swelling and prevent blood clotting Invertebrates (animals without backbones) Mollusks • came from Latin word mollis which means soft • occupy a vast range of aquatic and terrestrial habitats • include shellfish you eat and snails you see in garden • most have shells that protect their soft bodies Invertebrates (animals without backbones) Snail Mollusks • univalves such as snails have only one shell • bivalves - clams, oysters, scallops, and mussels have two shells • some like octopus and squid have shell-like structures called pen • some do not have shells like sea and graden slugs Invertebrates (animals without backbones) Squid Clams Mollusks • sensory and motor organs are found in the head-foot region • internal organs are found in the middle part or visceral mass • oyster and clam can produce pearls which are formed when sand gets in between the mantle and shell Invertebrates (animals without backbones) Mollusks • have relatively advanced digestive, circulatory and nervous system • have radula (tonguelike structure with many rows of chinitous teeth), used to scrape food material attached to rocks and surfaces as well as to filter food from water Invertebrates (animals without backbones) Mollusks • possess tentacles that help catch live prey and help them move through water by propulsion Invertebrates (animals without backbones) Echinoderms • include the spiny-skinned aquatic creature • include the starfish, sand dollar, and sea urchin • all live in a marine environment Invertebrates (animals without backbones) Echinoderms • most of them prefer staying at the bottom of the sea • some are free floating • have no head or tail region • radially symmetrical • have tube feet for locomotion Invertebrates (animals without backbones) Echinoderms • have water vascular system - a network of fluid-filled canals connected through a coelom or body cavity • acts like a hydraulic device, used for feeding, moving and sensing environment Invertebrates (animals without backbones) Echinoderms • have a simple digestive system that differs depending on what they eat • sometimes, stomach can sleep out and digest food outside the body Invertebrates (animals without backbones) Spider Arthropods • form the largest group of any organisms • thrive in all habitats • have hard outer body covered by exoskeleton, jointed legs, segmented body, compound eyes and specialized body parts Invertebrates (animals without backbones) Grasshoppe r Crab Spider Arthropods • undergo metamorphosis • their exoskeleton is replaced (molting) in order to grow larger • exoskeleton serves as protection, for feeding and locomotion • four types: crustaceans, arachnids, myriapods, insects Invertebrates (animals without backbones) Grasshoppe r Crab Crustaceans Arthropods • group of arthropods with two pairs of antennae • their bodies are divided into two regions: cephalothorax and abdomen • have gills for breathing • exoskeletons are very hard • shrimps, crabs, lobsters Invertebrates (animals without backbones) Arachnids Arthropods live on land have two body regions have four pair of legs breathe through their trachea or book lungs • spiders, mites, ticks and scorpions • • • • Invertebrates (animals without backbones) Arthropods • segmented animals • centipede - each segment has pair of legs; carnivorous and have poisonous fangs in their mouth, thus, sting are painful • millipede - has two pairs; detritivores, thus feed on dead plant and animal • both live hidden in soil, underneath rocks and dead logs Invertebrates (animals without backbones) Myriapods Arthropods • insects - largest group in arachnids • their body has three regions head, thorax and abdomen • thorax is divided into three segments, each containing a pair of legs • may have one to two pair of wings Invertebrates (animals without backbones) Insects Insects Arthropods • breathe through tracheae, which opens to thorax and abdomen • have antennae for chemical perception Invertebrates (animals without backbones) THANK YOU For Attending! 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