Biology 1120 - Lab 22

1120 Lab 22 - Introduction to Invertebrates

Feature	Porifera (Sponges)	Cnidaria (Jellyfish, hydras, anemones)	Platyhementhes (Flatworms)	Nematoda (Roundworms)	Rotifera (Rotifers)
Symetry	Asymmetrical or radial	Radial	Bilateral	Bilateral	Bilateral
Organization	Cellular	Tissue-- epidermis gastrodermis (endodermis)	Organ (mesoderm)-- sex organs nerves eyespots (Planarian)	Organ Systems-- digestive and reproductive	Organ Sytems
Digestion	Intracellular	Extracellular-- gastrovascular cavity	Extracellular-- in planarians	Complete "tube within a tube" (mouth and anus)	Complete
Body Cavity	Acoelomate	Acoelomate	Acoelomate	Pseudocoelomate-- partially lined body cavity	Pseudocoelomate
Sex	Hermaphroditic	Hermaphroditic	Hermaphroditic	Separate sexes	Separate sexes
Factoids	Sessile	Polyp (sessile) Medusa (motile)	Free-living - Planarians Eye spots, Head ganglia, Pharynx	Head (brain, mouth)	Head, Ciliated corona
	Spicules, Osculum	Cnidocytes (nematocysts)	Parasitic - tapeworms Head-like scolex No gastrovascular cavity sex organs in progottids		Cement gland in toe

General characteristics (level of organization, symmetry, body plan, etc) of organisms in each of the five phyla covered in this lab (sponges, cnidaria, flatworms, roundworms, and rotifers).
General characteristics of sponges ? no tissues usually covers it, the function of the osculum, and identification of sponge spicules.
The two morphological types (polyp and medusa, fig 22.4) of cnidaria, and which morphological shape the hydra (fig 22.5) has.
How the cnidaria paralyze their prey.
Which type of flatworm (free-living or parasitic) a planarian represents and how you can identify it as a free-living flatworm and not a parasitic one.
Identification of the eyespots, pharynx, gastrovascular cavity, cilia, ventral/lateral nerve cord(s), testis, ovary, and excretory pore of on the planarian model. See fig 22.8.
Identification of the intestine (and other organs your instructor may have indicated) of the dissected roundworm (model).
What the rotifers and roundworms have in common and what makes them more complex than animals in the sponge, cnidarian or flatworm phyla.
How each of these phyla's animals take in food and digest it.