Kingdom Animalia Multicellular Heterotrophs Lack cell walls Embryology Blastula stage

Animal diversity Simple, cellular level of organization to complex Invertebrates to vertebrates Most animals (>95%) are inverts Aside from very successful insects, most animals are marine Diverse morphologies, habitats, and adaptations

Phylum Porifera Sponges Habitat Body plan = asymmetry Mostly marine, few freshwater sessile Body plan = asymmetry Suspension filter feeders Cellular level (lacks true tissues and organs)

Cells with specific functions Porocytes: water canal Pinacocytes: flat protective cells Choanocytes: “collar cells” capture food (plankton) Amebocytes: transport food; differentiate into other cells Spicules: siliceous or calcareous skeletal structures

Diverse types & habitats Reproduction Asexual budding Sexual broadcast spawn Diverse types & habitats Tropical to temperate encrusting Subtropical bath sponges Deep water glass sponge

Phylum Cnidaria (nigh-dare-ia) Jellyfish, sea anemones, coral Nearly all marine Radial symmetry Two forms: medusa (swimming) and polyp Tissue level Reproduction Sexual and budding Stinging cells cnidocytes

Tissue layer: 2 layers Epidermis and gastrodermis Mesoglea is middle jelly layer rather than a true tissue

Class Hydrozoa Individual polyps or colonies of specialized polyps Feeding, reproductive, defense Sessile colonies Drifting colonies

Class Scyphozoa Dominant medusae stage Close relative Examples Sea Nettle Moon Jelly Upside-down Jelly Close relative Class Cubozoa Tropical Potent toxins

Class Anthozoa Solitary or colonial polyps w/out medusae stage Sea anemones Some with zooxanthellae symbionts Photosynthesizing protists Corals CaCO3 skeletons Environmentally valuable reefs Extremely susceptible to negative impacts Pollution, increased temp., etc

Phylum Ctenophora Comb jellies All marine Swim with 8 rows of ciliary combs or ctenes Use tentacles with colloblasts to capture prey Adhesive, non-stinging cells

Phylum Platyhelminthes Flatworms Bilateral symmetry Organ level Cerebral ganglia Simple brain Reproduction: hermaphrodites Asexual and Sexual Many parasitic

Incomplete gut Three tissue layers

Opisthorchis sinensis, Chinese liver fluke

Opisthorchis lifecycle

Cestoda

Similar to this mammal tapeworm example, are the marine parasitic tapeworms, “…as dense as seaweed forests, that live in the guts of sharks.”

Cestoda scolexes

Cestode proglottid 2 Testes Ovary Yolk gland

Phylum Nemertea Ribbon worms Circulatory system Complete gut Eversible proboscis

Phylum Nematoda Roundworms All environments Marine sediments (feed on bacteria) Parasitic to most marine animals Complete gut Reproduction Always sexual One of the biggest marine parasites measures 13 meters and is two centimeters in diameter …found in the placenta of the sperm whale.

Phylum Mollusca Very diverse Will discuss in more detail…

Phylum Annelida Segmented worms Repetitive body parts Earthworms Leeches Polychaetes Repetitive body parts Hydrostatic skeleton Flexibility and strength Longitudinal & circular muscles Coelomates Closed circulatory system Excretory organs Marine, moist land, and some freshwater Bilateral symmetry Some parasitic

Nereis Class Polychaeta Adaptations to predatory lifestyle Coelom Eyes, tentacles, jaws, etc Coelom Protective gut cavity Parapodia w/setae Respiratory, nervous, and locomotion