Porifera: latin porus (pore) and Greek fera (bearing) Sponges ◦ Greater than 9,000 species of sponges ◦ All aquatic, most marine species ◦ Pigmentation can be due to symbiotic algae ◦ Suspension feeders ◦ Adults are stationary, larvae are motile ◦ Asymmetrical, body organized as a collection of specialized cells
Jellyfish, Sea Anemones, Corals ~10000 species All aquatic-most marine One opening digestive system Exhibit radial symmetry ◦ Body parts arranged around an imaginary axis 2 distinct body forms ◦ Polyp-stationary, example: sea anemones ◦ Medusa-free-floating, example: jellyfish ◦ Some species exist as both forms in a lifetime Carnivorous: ◦ Stinging cells called cnidocytes ◦ Used for capturing prey and protection
Aurelia Jellyfish Cnidaria Fact: Praya (a deep sea hydrozoa) can reach lengths of 120 feet!
Flatworms Includes ~20000 species Two general categories: ◦ Free living and parasitic All have flattened bodies & exhibit bilateral symmetry with a head and a tail Centralized nervous system One opening digestive system Platyhelminthes Fact: The longest flatworm ever found was 90 foot long tapeworm.
Roundworms Currently ~90000 identified species, could be close to half a million Bilaterally symmetrical Can be free-living or parasitic ◦ Free living: Can eat other nematodes, microorganisms, or decaying organic material ◦ Parasitic: Can feed on animals (including humans) or plants
Segmented worms ~15000 species Marine, freshwater, and terrestrial Body consists of head, segmented body, and terminal portion Common groups: ◦ Polychaetes: largest group, marine ◦ Leeches: carnivorous or parasitic ◦ Earthworms: feed on decaying organic matter
~ identified species Mollusks are organized into three classes: ◦ Gastropods: snails, slugs ◦ Cephalopods: squids, octopus ◦ Bivalve: clams, oysters Many different ways of acquiring food ◦ Fast swimming predators, passive suspension feeders, herbivores, parasites All mollusks possess a soft body, a foot (for movement), gills, mouth, and anus. Most have a grasping organ called a radula.
Over 1.1 Million species, most species rich phylum ◦ 85% of all animals are arthropods ◦ 75% of all animals are insects. Exoskeleton comprised of chitin: ◦ Tough, flexible polysaccharide provides protection and prevents dehydration ◦ Exoskeleton cannot grow, must be shed and a larger one is grown, “molting” Arthropoda refers to “jointed appendages” Members of this phyla: crustaceans, arachnids, and insects
6000 species All marine and are have radial symmetry as adults Examples: Sea stars, brittle stars, sand dollars, sea urchins, sea cucumbers, sea apples Locomotion by water vascular system ◦ Water pressure is varied causing ‘tube feet’ to extend or retract Many are carnivorous: ◦ Will feed on stationary or slowly moving invertebrates
A few invertebrates and all vertebrates All possess: ◦ A hollow, dorsal nerve chord, notochord, gill structures, post-anal tail, segmented muscles Vertebrate chordates: ◦ Fish ◦ Amphibians ◦ Reptiles ◦ Birds ◦ Mammals Chordata Fact: Less than 5% of the animals that have ever lived on Earth have backbones.
Structures to identify: External: body segments, wings, leg parts, cuticle, exoskeleton, sclerites, tympanum, spiracles, cercus, ocellus, labrum, palps, maxilla, mandible, determine if male or female Internal: brain, crop, intestine, rectum, anus, ovary, heart, hemocoel, hemolymph