Phyla Cnidaria and Ctenophora Radial or biradial symmetry

Contents Phylum Cnidaria Phylum Ctenophora Unique characteristics Systems 1 (Integumentary, skeletal, muscle and digestive) 2 (Excretory, respiratory, circulatory and nervous) 3 (Endocrine and reproductive) Taxonomy Phylum Ctenophora Comparison to Cnidaria

Phylum Cnidaria Some unique characteristics Nematocysts Alternation of generations (polyp and medusa body forms) Planula larva Mesoglea

Cnidaria Systems 1 Integumentary Skeletal Muscle Digestive One cell layer (epidermis) Skeletal Hydrostatic or some with endoskeletons and/or exoskeleton of calcium carbonate (Anthozoa) Muscle None; epith-muscle cells (fibers from cells into mesoglea) Anthozoa may have muscles Digestive Incomplete

Cnidaria Systems 2 Excretory Respiratory Circulatory Nervous Isotonic in marine; some freshwater forms use contractile vacuoles) Respiratory No system , use cellular diffusion Circulatory No system, use cellular diffusion and mesoglea Nervous Nerve net (ring around the bell of medusa)

Cnidaria Systems 3 Endocrine Reproductive Have hormones, secreted by nervous system Reproductive Alternation of generations, vary as to dominant stage Medusa is the sexual body plan Polyp is the asexual body plan Planula larva Dioecious or monoecious

Cnidaria Taxonomy Class Hydrozoa (hi-dro-zo-ah) Hydra, Obelia, Gonionemus, Physalia Class Scyphozoa (sky-fo-zo-ah) Aurelia Class Anthozoa (an-tho-zo-ah) Metridium Tubipora Gorgonia Other anthozoan coral Class Cubozoa (ku-bo-zo-ah) No specimens

Class Hydrozoa Alternation of generation with polyp as the dominant body plan Incomplete digestive with an unbranched gut. Mesoglea thin Medusa with a velum

Class Hydrozoa Genus— Hydra CS through hydra

Class Hydrozoa Genus— Obelia

Class Hydrozoa Genus— Gonionemus

Class Hydrozoa Genus— Physalia

Class Scyphozoa Alternation of generation with medusa the dominant body plan Incomplete digestive with four branches Mesoglea thick with some cells Medusa without velum

Class Scyphozoa Genus— Aurelia

Class Anthozoa No alternation of generation - polyps only Incomplete digestive with 6 to 8 branches (septia) Nematocyst in the gut (acontia) Mesoglea thick and with muscle tissue Coral Reefs

Class Anthozoa Genus — Metridium

Class Anthozoa Genus — Tubipora

Class Anthozoa Genus — Gorgonia Sea fan String coral

Other Anthozoan Coral Astrangia Fungia Brain coral Sea pansy Lettuce coral

Coral Reefs Fringing reef Barrier reef Atolls Close to land mass none or a narrow lagoon between land and shore. Barrier reef Has a wide and deep lagoon between reef and shore line. Atolls Reefs that encircle a lagoon, but there is no island

Phylum Ctenophora Unique Characteristics Comb plates Medusa only Luminescence common Position of paired tentacles changes symmetry to biradial

Comparison Ctenophora to Ctenophora Differences No alternation of generations (medusa only) No nematocysts Biradial symmetry, two tentacles Combs Complete digestive system May be triploblastin Similarities Aboral-oral axis Nerve net Lack of organ systems

Taxonomy Phylum Ctenophora Class Tentaculata (ten-tack-u-la-ta) Pleurobrachia

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