Invertebrates Packet #77 Chapters 33 & 47

Introduction I

Introduction II

Invertebrates- Animals Without Backbones Ninety five percent of all known animals species are invertebrates. Ninety five percent of all known animals species are invertebrates. Invertebrates have a worldwide distribution ranging from deep sea hydrothermal vents to the polar deserts of Antartica. Invertebrates have a worldwide distribution ranging from deep sea hydrothermal vents to the polar deserts of Antartica.

Invertebrates II Invertebrates can be separated into multiple categories: Invertebrates can be separated into multiple categories: Aceolomates Aceolomates The Sponges The Sponges The Cnidarians The Cnidarians The Flatworm The Flatworm Protostomes (Blastopore = Mouth) Protostomes (Blastopore = Mouth) The Roundworms The Roundworms The Segmented Worms The Segmented Worms The Mollusks The Mollusks The Arthropods The Arthropods Deuterostomes (Blastopore = Anus) Deuterostomes (Blastopore = Anus) The Echinoderms The Echinoderms The Chordates The Chordates Tunicates Tunicates Lancelets Lancelets

ACEOLOMATES

The Sponges Phylum Porifera Phylum Porifera The Sponges The Sponges Hermaphrodite, sessile animals Hermaphrodite, sessile animals They have no nerve or muscle tissue but individual cells can react to environmental changes. They have no nerve or muscle tissue but individual cells can react to environmental changes.

The Cnidarians Phylum Cnidaria Phylum Cnidaria There are four classes of this phylum There are four classes of this phylum Hydrozoa—Hydra Hydrozoa—Hydra Cubozoa—Sea worms Cubozoa—Sea worms Scyphozoa—Jelly fish Scyphozoa—Jelly fish Anthozoa—Sea anemones Anthozoa—Sea anemones Organisms have cnidocytes Organisms have cnidocytes Organelles with stinging abilities Organelles with stinging abilities Organisms have nerve cells that are irregular and non- directional. Organisms have nerve cells that are irregular and non- directional. Occurs in two forms Occurs in two forms Polyps Polyps Medusa Medusa

The Flatworms Phylum Platyheminthes Phylum Platyheminthes Most are hermaphrodites that are free living or parasitic. Most are hermaphrodites that are free living or parasitic. Organisms have sense organs and a simple brain Organisms have sense organs and a simple brain Include tapeworms Include tapeworms

PROTOSTOMES

The Roundworms Phylum Nematoda Phylum Nematoda These organisms are normally associated with being parasitic or pests. These organisms are normally associated with being parasitic or pests. Parasites Parasites Hookworms Hookworms Pinworms Pinworms Agricultural pests Agricultural pests Attacking plant roots Attacking plant roots

The Segmented Worms Phylum Annelida Phylum Annelida Organisms have large compartmentalized coelom that serves as a hydrostatic skeleton. Organisms have large compartmentalized coelom that serves as a hydrostatic skeleton. Includes the leeches and earthworms. Includes the leeches and earthworms. Earthworms have setae which are bristles composed of chitin. Earthworms have setae which are bristles composed of chitin.

The Mollusks Phylum Mollusca Phylum Mollusca Soft bodied animals usually covered by a shell Soft bodied animals usually covered by a shell Organisms have a ventral foot, which is necessary for locomotion, and have rasplike radula which functions as a scraper in feeding. Organisms have a ventral foot, which is necessary for locomotion, and have rasplike radula which functions as a scraper in feeding. Include squids, octopus, snails and slugs. Include squids, octopus, snails and slugs.

The Arthropods Phylum Arthropoda Phylum Arthropoda These organisms are segmented animals with jointed specialized appendages. These organisms are segmented animals with jointed specialized appendages. The organisms have exoskeletons that are composed of protein and chitin. The organisms have exoskeletons that are composed of protein and chitin. Include the centipedes, millipedes, lobsters, crabs and insects. Include the centipedes, millipedes, lobsters, crabs and insects.

DEUTEROSTOMES

The Echinoderms Phylum Echinodermata Phylum Echinodermata These are sessile slow moving animals that have “spiny” skin. These are sessile slow moving animals that have “spiny” skin. Included are the sea lilies, sea stars, sea urchins, brittle stars and sea cucumbers. Included are the sea lilies, sea stars, sea urchins, brittle stars and sea cucumbers.

Phylum Chordata Subphylum Urochordata Tunicates Tunicates Suspension feeding, marine animals with tunics Suspension feeding, marine animals with tunics Larvae have typical chordate characteristics Larvae have typical chordate characteristics Free swimming Free swimming Adults of most groups are sessile suspension feeders Adults of most groups are sessile suspension feeders

Phylum Chordata Subphylum Cephalochordata Lancelets Lancelets Small segmented, fishlike animals that exhibit chordate characteristics Small segmented, fishlike animals that exhibit chordate characteristics

Characteristics of Common Animal Phyla PhylumSample Animal AcoelomatePseudo- coelomate CoelomateSymmetryNumber of Germ Layers PoriferaSpongeXRadial2 CnidariaHydraXRadial2 Platyhelminthe s PlanariaXBilateral3 NematodaRoundworm; Pinworm XBilateral3 AnnelidaEarthwormXBilateral3 MolluscaSlug; ClamXBilateral3 ArthropodaInsect; SpiderXBilateral3 Echinodermat a Starfish; Sea urchin XBilateral3

REVIEW

Review I Invertebrates Aceolmates Sponges Cnidarians Flatworms Protosomes Roundworms Earthworms Mollusks Arthropods Enchinoderms Deuterosomes Tunicates Lancelets