Invertebrates Animals without a backbone

Phylum Porifiera: Sponges Filter Feeders Move fluid and bodies by Choanocytes Spines called spicules Asymmetrical Asexual and Sexual –Hermaphrodites; produce eggs and sperm at different times

Phylum Cnidarians: Jellyfish, Hydras, Coral, Sea Anemone Radial Symmetry Two body Types Medusa and Polyp –Medusa: Jellyfish Polyp: Hydra or Sea Anemone Cnidocytes: Harpooning cells to sting prey Only one body cavity for digestion.

Phylum Platyhelminthes: Flat Worms. Bilateral Symmetry Flat bodies allows for diffusion of food and gases. No circulatory or digestive system. Class Turbellaria: Marine flatworms Class Cestoda: Tape worms Class Trematoda: Flukes cause schitsomiasis

Phylum Nematoda: Roundworms Bilateral Symmetry One way digestive system!!!!! Pseudocoelum Whip-like movement: muscles push against body cavity. Trichinella- from uncooked pork Heart worm -Dogs Pin Worm – itchy anus

Phylum Molluska: Snails, slugs, oysters, clams, octopus, and squid Bilateral Symmetry True Coelum –Allows for circulatory, respiratory, etc. systems Mantle surrounds body Most have a Radula-Rasping tongue Others have Beaks One way digestive system

Phylum Molluska: continued All have sexual reproduction Gastropods: Snails and slugs Bi-Valves: Oysters, Muscles, and Clams (Filter Feeders). Cephalopods: Nautilus (only one with shell), Squids, Octopus, and cuttlefish –Hightly Intelegent: well developed brain –1 st closed circulatory system found in Octopus and Squid. –Giant Squid 15 inch eyes

Phylum Annelida: Earthworms and Leeches 1 st segmented Animals. Body is ring shaped Coelmates: True body cavities with two way digestive systems Primitive brain = cerebral ganglia Nerve chord and blood vessels Light sensitive organs at both ends 5 hearts. Digestive system: Mouth to Esophagus to Crop (storage) to Gizzard (grinding) intestine (absorbing) to anus (out)

Phylum Echinodermata: Starfish, Sea cucumbers, Sea Urchins Found in Oceans Spines cover body: sharp projections Tube feet use water to create suction and move. Starfish: Mouth that is pushed out of the body and liquefies prey. Can regenerate arms or Rays of Starfish.

Phylum Arthorpoda: Lobsters, Spiders, and Ants Animals with jointed appendages. Exoskeleton: Outgrow they Molt Two or three body sections Crustaceans: Lobsters, shrimp, crab. 2 body sections, 10 legs. Breath with gills. Arachnids: Spiders, scorpions, ticks. Eat garden pests: 2 body sections, 8 legs. Insects: Wasp, Ant, Grasshopper. 3 body sections and 6 legs. Bad for crops. Good for honey and silk. Food source for many

Economic importance of Invertebrates Earthworms: Decomposers, make good dirt. Ladybugs: Voracious Predators Crustaceans and Mollusks: Food Source Insects can be pollinators or destructive to crops. Round and Flat worms: can be parasitic to animals and plants- crop damage.

Ask about the Guinea Worm