Animals • are multicellular eukaryotes. • have specialized cells that carry out specific functions. • are heterotrophs. • are capable of locomotion at some point in their life cycle. • have sense organs and can respond rapidly to stimuli in their environment. • reproduce sexually.
Sponges • Asymmetrical • An assemblage of different kinds of specialized cells • Adults sessile. • Skeleton lacking or made of spicules.
Hydras, corals, jellyfish, sea anemones • Two tissue layers with nerve and muscle tissues • Nematocysts- stinging cells • Radial symmetry • Two main life forms: freeswimming medusa or stationary polyp
Comb jellies • Radial symmetry • Two tissue layers with nerve and muscle tissues • Most have colloblasts and capture prey by squirting glue on them • Most have 8 strips of cilia called comb rows used for locomotion
Flatworms • Bilateral symmetry with a head and a tail • Centralized nervous system • Three tissue layers, but no coelom (body cavity) • Hermaphroditic • Body has only one opening serving as both a mouth and an anus • No circulatory system, body is flat to allow for oxygen diffusion
Rotifers-Commonly called â€œWheel Animalsâ€?
Microscopic or near microscopic psuedocoelomates Some sessile, some free-swimming Have bilateral symmetry with a head, trunk and foot Have a small brain and nervous system
Nematodes AKA Roundworms • Most diverse phylum of pseudocoelomates • Body has bilateral symmetry, head has radial symmetry • Tube within a tube body design, one-way digestive system with both a mouth and an anus • Also has a nervous, excretory and reproductive system, but no circulatory or respiratory system
Segmented Worms • Bilateral symmetry with true body cavity (Coelom) • Body wall made of circular and lengthwise muscles • Complete circulatory system • Continuous one-way gut
Bivalves, gastropods and cephalopods • Most have a calcium carbonate shell secreted by the mantle- a layer of tissue that surrounds the internal organs and gills • Muscular “foot” used to slide, dig, or jump • Some propel using their siphon as a water jet • Radula- feeding device like a toothed rasping tongue • Complete digestive tract with two ends- mouth and anus
Crustaceans, arachnids, insects, millipedes, centipedes • Hard exoskeleton made of chitin and protein • Jointed appendages and a segmented body • Must molt to grow • 80% of all animal species • Inhabit nearly every niche on Earth
Sea Stars, Sea Lilies, Sea Urchins, Sea Cucumbers, and Brittle Stars • Five part radial symmetry • Complete digestive tract with two ends • Hard but flexible bodies with an internal skeleton made of interlocking calcium plates under thin skin • Water vascular system operates tube feet used for locomotion and feeding and facilitates respiration
Includes Tunicates, Lancelets, and Vertebrates like Amphibians, Reptiles and Mammals • Bilateral symmetry • Complete, one-way, digestive tract • All have a notochord; most have a backbone • Most have an internal skeleton of bones • Increased complexity made possible by much more DNA