Animal Diversity: Poriferans, Cnidarians, Helminths

Cambrian Explosion

Major adaptive radiation of animal phyla 540 mya

Poriferans

Invertebrate group including sponges

Cnidarians

Invertebrate group including jellyfish and corals

Helminths

Invertebrate group including flatworms and roundworms

Lancet fluke

Parasite that manipulates ants to help itself

Jasper Lawrence

Person who relieved allergies through a method

Parasites

Organisms that help the immune system

Animal Evolution

How animals have changed and diversified over time

Animal Phyla

Over a dozen groups including sponges, jellyfish, flatworms, roundworms, snails, earthworms, crustaceans, insects, sea stars, and chordates

Cells → tissues → organs → organ systems

Progression of organization in animals

Diploblastic

Animals with two germ layers (endoderm and ectoderm)

Acoelomate → Psuedocoelomate → Coelomate

Progression of body cavity development

Asymmetry

Lack of symmetry (seen in sponges)

Radial symmetry

Body parts arranged around a central axis (seen in starfish)

Bilateral symmetry

Body parts divided into similar halves (seen in cats)

Metazoa

Monophyletic grouping of all animals

Parazoa

Grouping of animals including sponges with no true tissue type

Eumetazoans

Grouping of animals with tissues (excluding sponges)

Symmetry

Division between animals with different types of symmetry

Germ Layers

Endoderm, mesoderm, and ectoderm in animals

Diploblastic

Animals with two germ layers (endoderm and ectoderm)

Triploblastic

Animals with three germ layers (endoderm, mesoderm, and ectoderm)

Acoelomate

Animals without a body cavity

Pseudocoelomate

Animals with a body cavity lined on one side

Coelomate

Animals with a body cavity lined on both sides

Protostomia

Group of animals with specific developmental characteristics

Deuterostomia

Group of animals with specific developmental characteristics

Ecdysozoa

Group of animals that molt a cuticle as they grow

Lophotrochozoa

Group of animals with lophophores and/or trochophore larvae

Complete Gut

Animals with two openings in their digestive system

Cephalization

Development of a head region

Segmentation

Division of body into segments

Porifera

Primitive animal group including sponges

True Tissues

Tissues found in animals excluding sponges

Eumetazoans

Animals with true tissues

Cnidaria

Eumetazoans with two germ layers and a gastrovascular cavity

Hydrostatic Skeleton

Skeleton based on a gastrovascular cavity

Medusa

Body form of cnidarians for reproduction and dispersal

Polyp

Body form of cnidarians for feeding

Cnidocytes

Cells in cnidarians with specialized stinging organelles

Flatworms

Bilateral animals with three germ layers and cephalization

Helminths

Parasitic worms including flatworms and roundworms

Planarian

Free-living flatworm

Trematodes

Parasitic flatworms with suckers for attachment

Cestodes

Parasitic flatworms with a modified head region

Nematodes

Roundworms with a complete gut

Helminths

Parasitic worms including flatworms and roundworms

Coelom

Body cavity that is an important evolutionary advancement

Sponges

Feed by filtering water through pores and canals

Spicules

Structures in sponges made of calcium carbonate or silica

Choanocytes

Specialized feeding cells in sponges

Osculum

Large opening at the top of a sponge

Amoebocytes

Cells in sponges that transport nutrients

Polyp and Medusa

Body forms of cnidarians

Cnidocytes

Cells in cnidarians with specialized stinging organelles

Flatworms

Bilateral animals with three germ layers and cephalization

Roundworms

Nematodes with a complete gut

Helminths

Parasitic worms including flatworms and roundworms

Cestode Adaptations

Specialized features for parasitism in tapeworms

Trematodes and Nematodes

Parasitic flatworms and roundworms and the infections they cause

Heartworm

Deadly roundworm infection in cats and dogs

Coelom

Important evolutionary advancement in animals

Sponges

Filter water through pores and canals for feeding

Spicules

Structures in sponges made of calcium carbonate or silica

Choanocytes

Specialized feeding cells in sponges

Osculum

Large opening at the top of a sponge

Amoebocytes

Cells in sponges that transport nutrients

Cephalization

Development of a head region

Spicules

Structures in sponges made of calcium carbonate or silica

Choanocytes

Specialized feeding cells in sponges

Osculum

Large opening at the top of a sponge

Epidermis

Outer layer of cells in sponges

Amoebocytes

Cells in sponges that transport nutrients

Ostia

Pores in sponges where water enters

Cestode Adaptations

Specialized features for parasitism in tapeworms

Trematodes and Nematodes

Parasitic flatworms and roundworms and the infections they cause

Planaria

Free-living flatworm

Liver Flukes

Parasitic flatworms that infect the liver

Tapeworm

Parasitic flatworm with a modified head region

Roundworm

Nematode with a complete gut

Dog Hookworm

Roundworm that is a concern for pet owners

Heartworm

Deadly roundworm infection in cats and dogs

Coelom

Body cavity that is an important evolutionary advancement

Sponges

Filter water through pores and canals for feeding

Spicules

Structures in sponges made of calcium carbonate or silica

Choanocytes

Specialized feeding cells in sponges

Osculum

Large opening at the top of a sponge

Amoebocytes

Cells in sponges that transport nutrients

Polyp and Medusa

Body forms of cnidarians

Cnidocytes

Cells in cnidarians with specialized stinging organelles

Flatworms

Bilateral animals with three germ layers and cephalization

Roundworms

Nematodes with a complete gut

Helminths

Parasitic worms including flatworms and roundworms

Cestode Adaptations

Specialized features for parasitism in tapeworms

Trematodes and Nematodes

Parasitic flatworms and roundworms and the infections they cause

Heartworm

Deadly roundworm infection in cats and dogs

Coelom

Important evolutionary advancement in animals

Sponges

Filter water through pores and canals for feeding

Spicules

Structures in sponges made of calcium carbonate or silica

Choanocytes

Specialized feeding cells in sponges