Kingdom Animalia

Characteristics of All Animals Heterotrophic, multicellular eukaryotes. Lack cell walls. Use oxygen for aerobic respiration. Primarily sexual reproduction. *Specialized nervous and muscle tissue.

Body Plan Used to classify animals. Features: –Body symmetry. –Degree of cell organization. –Presence of a coelom (internal body cavity).

Body Symmetry Bilateral Radial Asymmetric

Cell Organization

Presence of a Coelom Body cavity that contains internal organs.

Ancestor? It is believed that animals descended from colonial flagellated protists. E.g., choanoflagellates…resembles cells in modern sponges

Phylum Porifera & Phylum Cnidaria

Phylum Porifera “The Sponges” Most primitive animals. All aquatic and mostly marine. Sessile. Watch This!!!

Phylum Porifera Invertebrate. Asymmetrical. No mouth, digestive cavity, muscles and nervous system. Flagellated cells line a central cavity.

Phylum Porifera Absorbs water through tiny pores (ostia). Expels water through larger pores (oscula). Watch This!!!

Phylum Porifera Reproduction 1.Reproduce Sexually: Many are hermaphrodites. 2.Reproduce Asexually: Budding. Watch This!!! And This!!!

Phylum Cnidaria Invertebrate. Radial symmetry. Cells organized into tissues. e.g., jellyfish, sea anemones and corals. Watch This!!!

Phylum Cnidaria All cnidarians have stinging structures within their tentacles. Toxic substances paralyze prey. Mouth/anus leads to gastrovascular cavity. Where digestion, circulation and gas exchange occur.

Phylum Cnidaria Lifecycle for most alternates between asexual sessile polyps and sexual free-swimming medusas.

Phylum Cnidaria Portuguese Man-of-War Tentacles may be up to 50 m in length. Watch This!!!