Chapter 11: INVERTEBRATES Copyright © by Holt, Rinehart and Winston. All rights reserved.

Chapter 11: INVERTEBRATES What is an animal? An organism’s structure: Study of how an organism functions: Levels of Organization: Copyright © by Holt, Rinehart and Winston. All rights reserved.

Functions of Animals Major functions of Animals: 1.Obtaining food and oxygen What do animals eat? How do animals get oxygen? 2.Keeping internal conditions stable Examples: 3.Moving Examples: 4.Reproducing (two types) Copyright © by Holt, Rinehart and Winston. All rights reserved.

Symmetry A balanced arrangement of body parts that is characteristic of many animals Bilateral: Radial: No symmetry: Copyright © by Holt, Rinehart and Winston. All rights reserved.

Symmetry Copyright © by Holt, Rinehart and Winston. All rights reserved.

Classification of Animals There are more than 1.5 million identified species Classifying animals helps biologists make sense of this diversity Scientists often correlate strength of relationship between species with the number of characteristics that they share Animals are classified according to similarities in: body structure body development similarity in DNA sequence 35 Phyla: 1 for vertebrates, the rest for invertebrates Copyright © by Holt, Rinehart and Winston. All rights reserved.

Invertebrates Chapter 15 Section 1: Simple Invertebrates Section 2: Mollusks and Annelid Worms Section 3: Arthropods Section 4: Echinoderms Copyright © by Holt, Rinehart and Winston. All rights reserved. End of Slide

Simple Invertebrates Section 1 Objectives Describe how sponges and cnidarians get food, move around, and reproduce. Explain what a larva is. Describe the two body plans of cnidarians.. Copyright © by Holt, Rinehart and Winston. All rights reserved. End of Slide

Simple Invertebrates Section 1 Video clip: sponges Copyright © by Holt, Rinehart and Winston. All rights reserved. End of Slide

Simple Invertebrates Section 1 Copyright © by Holt, Rinehart and Winston. All rights reserved. How Do Sponges Eat? Adult sponges stay in one place. A sponge sweeps water into its body through special cells called COLLAR cells. Reproduction Sexual reproduction: Each sponge produces BOTH eggs AND sperm!. Asexual reproduction: parent breaks off a chunk of cells that becomes another sponge Body structure Sponges have no symmetry, no body organs, no body tissues. They are just a collection of cells that work together. Sponges End of Slide

Simple Invertebrates Section 1 Cnidarians Two Body Forms A cnidarian body can have one of two forms— the medusa or the polyp form. MEDUSA: bowl shaped, swimming form POLYP: vase shaped, attached to a surface (non-swimming) Stinging Cells All cnidarians have tentacles covered with stinging cells. They are used for defense and to capture food. Eating Catch animal with stinging cells. Use tentacles to pull prey into mouth. Move prey into gut, where it is digested. Expel waste through mouth. Copyright © by Holt, Rinehart and Winston. All rights reserved. End of Slide

Simple Invertebrates Section 1 Cnidarians Movement Cnidarians have “nerve nets” that signal their cells to move (beating jellyfish, somersaulting hydra)beating jellyfishsomersaulting hydra Copyright © by Holt, Rinehart and Winston. All rights reserved. End of Slide

Simple Invertebrates Section 1 Cnidarians Copyright © by Holt, Rinehart and Winston. All rights reserved. End of Slide

Simple Invertebrates Section 1 BuddingBudding (Asexual Reproduction) Copyright © by Holt, Rinehart and Winston. All rights reserved. End of Slide

Simple Invertebrates Section 1 Worms have long, narrow bodies, and no legs 3 kinds: flatworms, round worms, segmented worms Phyla: Platyhelminthes, Nematoda, Annelida What kind of symmetry? They have tissues, organs, and organ systems Copyright © by Holt, Rinehart and Winston. All rights reserved. End of Slide

Simple Invertebrates Section 1 Worms Nervous system: simple brain and sense organs Reproduction: some do asexual reproduction Most species can reproduce sexually Male and female individuals Hermaphrodites Copyright © by Holt, Rinehart and Winston. All rights reserved. End of Slide

Simple Invertebrates Section 1 Flatworms Planarians Planarians are free-living. They live in freshwater lakes and streams. Most planarians are predators and scavengers. They insert a “feeding tube” into their prey. They have eyespots.Planarians Flukes Flukes are parasites. A parasite is an organism that invades and feeds on the body of a host. Most flukes live and reproduce inside the bodies of other animals.Flukes Tapeworms Tapeworms are parasites. They often have more than one host in their lifetime.Tapeworms All flatworms have ONE body opening! Mouth = anus Copyright © by Holt, Rinehart and Winston. All rights reserved.

Simple Invertebrates Section 1 Roundworms Roundworms have bodies that are long, slim, and round, like spaghetti. They have a digestive system that is a tube, open at both ends. (mouth is NOT the anus) Copyright © by Holt, Rinehart and Winston. All rights reserved. End of Slide

Mollusks and Annelid Worms Section 2 Annelid Worms (Segmented worms) Earthworms Earthworms are the most common annelid worms. Each earthworm has 100 to 175 segments. Other segmented worms: leeches, sea-floor worms Have a one-way digestive system with mouth and anus Well-developed organ system Closed circulatory system: blood is held in blood vessels, can be pumped around the body Copyright © by Holt, Rinehart and Winston. All rights reserved. End of Slide

Mollusks and Annelid Worms Section 2 Mollusks Body structure: Soft, unsegmented body. Sometimes has a shell. Mantle: Thin tissue that covers internal organs Foot: Muscular organ Symmetry: Bilateral Digestive system: Two openings (mouth AND anus) Copyright © by Holt, Rinehart and Winston. All rights reserved. End of Slide

Mollusks and Annelid Worms Section 2 Mollusks Circulatory system: OPEN! (not like earthworms) Blood sloshes around the body cavity Gills: Allow oxygen from the water to enter the body 3 major groups of mollusks: gastropods, bivalves, cephalopods Copyright © by Holt, Rinehart and Winston. All rights reserved.

Gastropods The gastropods are the largest group of mollusks Have ONE external shell OR NO shell at all Examples: Snails, slugs Copyright © by Holt, Rinehart and Winston. All rights reserved.

Ocean gastropods: video Copyright © by Holt, Rinehart and Winston. All rights reserved.

Bivalves Have two shells held together by hinges and strong muscles Examples: clams, oysters, scallops, mussels Giant clam: video Copyright © by Holt, Rinehart and Winston. All rights reserved.

Cephalopods Ocean Dwelling Foot is adapted to form tentacles around mouth Carnivorous Examples: Octopuses, cuttlefish, nautiluses, squids Camouflage defense: video Copyright © by Holt, Rinehart and Winston. All rights reserved. End of Slide

Arthropods Characteristics of Arthropods Copyright © by Holt, Rinehart and Winston. All rights reserved. Segmented and Specialized: Like annelid worms, arthropods are segmented. Jointed Limbs called APPENDAGES: Legs or other body parts that bend at the joints. An External Skeleton: The hard, external structure that covers the outside of the body is an exoskeleton. Major Groups: Crustaceans, arachnids, centipedes and millipedes, insects End of Slide

Arthropods Kinds of Arthropods Copyright © by Holt, Rinehart and Winston. All rights reserved. Other details: bilateral symmetry Open circulatory system Digestive system with TWO openings Sexual reproduction End of Slide

Arthropods Exoskeleton Copyright © by Holt, Rinehart and Winston. All rights reserved. Waxy: protects the animal, prevents evaporation Molting: Process of shedding exoskeleton End of Slide

Arthropods Crustaceans Copyright © by Holt, Rinehart and Winston. All rights reserved. 2 or 3 body sections 5 or more pairs of legs 2 pairs of antennae Have gills Metamorphosis: change from larva form to adult form End of Slide

Arthropods Arachnids Copyright © by Holt, Rinehart and Winston. All rights reserved. 2 body sections 1: head + midsection 2: abdomen (reproductive organs, some digestive organs) 4 or more pairs of legs no antennae End of Slide

Arthropods Centipedes, millipedes Copyright © by Holt, Rinehart and Winston. All rights reserved. 2 body sections Numerous pairs of legs Centipedes: one pair of legs per segment Millipedes: two pairs of legs per segment Video clip End of Slide

Arthropods Insects Copyright © by Holt, Rinehart and Winston. All rights reserved. 3 body sections 1: Head 2: Thorax – legs and wings attach to this section 3: Abdomen – contains internal organs 6 legs Insects go through complete metamorphosis OR gradual metamorphosis End of Slide

Arthropods Complete Metamorphosis Copyright © by Holt, Rinehart and Winston. All rights reserved. Egg  Larva  Pupa (enclosed in case)  Adult Example: Butterflies End of Slide Gradual Metamorphosis Egg  Nymph (looks like a miniature adult)  Adult Example: Grasshoppers and cockroaches

Stages of Complete Metamorphosis Copyright © by Holt, Rinehart and Winston. All rights reserved.

Stages of Incomplete Metamorphosis Copyright © by Holt, Rinehart and Winston. All rights reserved.

Echinoderms Section 4 Bellringer Echinoderms include marine animals such as sea stars, sea urchins, and sea cucumbers. All these organisms are slow moving animals that live on the ocean floor. How do you think they protect themselves from predators? Write your response in your science journal. Copyright © by Holt, Rinehart and Winston. All rights reserved.

Echinoderms Section 4 Objectives Copyright © by Holt, Rinehart and Winston. All rights reserved. Describe the endoskeleton, nervous system, and water vascular system of echinoderms. Explain how an echinoderm’s body symmetry changes with age. Describe five classes of echinoderms. End of Slide

Echinoderms Section 4 Spiny Skinned Copyright © by Holt, Rinehart and Winston. All rights reserved. Endoskeleton The name echinoderm means “ spiny skinned.” An echinoderm’s internal skeleton is called an endoskeleton. Bilateral and Radial? Adults vs.. Larvae Adult echinoderms have radial symmetry. But they develop from larvae that have bilateral symmetry. End of Slide

Echinoderms Section 4 The Nervous System Copyright © by Holt, Rinehart and Winston. All rights reserved. Endoskeleton All echinoderms have a simple nervous system similar to that of a jellyfish. Around the mouth is a circle of nerve fibers called the nerve ring. Water Vascular System Fluid-Filled Canals The water vascular system is a system of canals filled with fluid. A water vascular system is illustrated on the next slide. End of Slide

A Water Vascular System Section 4 Copyright © by Holt, Rinehart and Winston. All rights reserved.

Echinoderms Section 4 Kinds of Echinoderms Copyright © by Holt, Rinehart and Winston. All rights reserved. Brittle Stars and Basket Stars Brittle stars and basket stars look like sea stars. But these echinoderms have long, slim arms and are often smaller than sea stars. Sea Urchins and Sand Dollars Sea urchins and sand dollars are round. Their endoskeletons form a solid, shell- like structure. End of Slide

Echinoderms Section 4 Kinds of Echinoderms continued Copyright © by Holt, Rinehart and Winston. All rights reserved. Sea Lilies and Feather Stars Sea lilies and feather stars have 5 to 200 feathery arms. Sea Cucumbers Like sea urchins and sand dollars, sea cucumbers have no arms. A sea cucumber has a soft, leathery body. End of Slide

Invertebrates Chapter 15 Concept Map Copyright © by Holt, Rinehart and Winston. All rights reserved. Use the following terms to complete the concept map on the next slide: cnidarians, symmetry, invertebrates, mollusks, annelid worms, snails, bilateral, sponges, coral, asymmetry.

Concept Map Chapter 15 Copyright © by Holt, Rinehart and Winston. All rights reserved.

Concept Map Chapter 15 Copyright © by Holt, Rinehart and Winston. All rights reserved.