The Animal Kingdom

Unifying Animal Concepts: 1. They are classified according to body plan, symmetry, number of germ layers, & level of organization. 2. There is an increase in complexity when groups are arranged in order from first evolved to most recent. 3. Animals are adapted to their way of life. (Active vs. inactive, aquatic vs. terrestrial)

Animal Characteristics Heterotrophic- have to take in food Generally have an active lifestyle Multicellular Organized cells into tissues, tissues into organs

2 Groups of Animals 1. Invertebrates: lack a dorsal backbone

2. Vertebrates: have a backbone made up of vertebrae

Animal Body Plans 1. Sac Plan: One opening for food intake and waste excretion. 2. Tube within a tube: one entrance for food, another exit for waste.

Animal Symmetry Asymmetry: No Particular Symmetry Radial Symmetry: Animal is organized circularly (like a wheel). Tend to be sessile. Why? –Can reach food in all directions around them! Bilateral Symmetry: definate left and right halves.

Animal Germ Layers Ectoderm: Outer Endoderm: Inner These 2 form tissue level organization. Mesoderm: Middle Animals with all 3 have organ level organization.

Internal Body Cavities Acoelomate: NO open space in which internal organs are located Coelomate: have a true Coelom - open space

Primitive Invertebrates Sponges Cnidarians Flatworms Roundworms

Classification Common Name: Sponge Scientific Name: Grantia Phylum: Porifera Class: Calcarea Other: 5,000 species; 150 species live in fresh water

SPONGES Phylum: Porifera “Pore Bearer” Body Plan: Sac; 2 cell layers with jellylike mesophyll in between Body Cavity: Acoelomate, hollow cylinder Symmetry: Asymmetry Cell Specialization: Collar Cells (Choanocytes) & Amoebocytes; cell recognition Other: most are marine, abundant in warm coastal waters

Sponge Life Processes Absorption: Collar cells with tiny flagella draw water & food (plankton) into pores, digested by food vacuoles in cells Feeding: Sessile filter feeders Digestion: food vacuoles in cells Respiration: Water flowing through pores

Sponge Life Processes Circulation: Amoebocyte cells transport nutrients from cell to cell, physically move (crawl) within the body wall Excretion: Carbon dioxide & waste diffuse into water; Osculum = large opening on the top Secretion: Amoebocytes produce spicules and sex cells

Spicules Light Microscope Electron Microscope

Sponge Life Processes Response: None, no nervous system Movement: Adult = none; Larvae = ciliated and free swimming Reproduction: Hermaphrodite; Sexual - fertilization to form a zygote in the water (NO self fertilization!) = Ciliated Larvae Asexual - budding (gemmule formation during harsh conditions) & regeneration

Sponge Life Processes Support: Spicules = calcium carbonate & silica; very hard. Spongin = Protein; soft

Ecological Relationships Mostly Marine Food for snails, fish, starfish

Body Systems Compared to Humans Fertilization: Separate sperm and egg cells

Sponge Diagram

Question: How much deeper would the oceans be if sponges didn’t live there? Sponges drink about 64 glasses of water a day and some species filter almost 20,000 times their volume in a day.

Worlds largest Sponge: Barrel Shaped Loggerhead Sponge = 4 ft. high; 3 ft. diam. Found in the West Indies & off of Florida Largest ever found = Wool Sponge 6 ft. in circumference Deepest Sponges = found at depths of up to 18,500 ft.

In 1994, a “predatory” sponge was discovered in a Mediterranean cave near Marseilles, France, this sponge actually covers the prey and then consumes it. If part of a sponge breaks off, it can actually become a separate, thriving sponge.