Introduction to the Animal Kingdom
The animal kingdom is distinguished as multicellular organisms that ingest their food.
Animals have been categorized into different groups based primarily on their morphology
(form), though additional information from genetic studies have allowed biologists to
revise the relationships among and within groups. Currently, there are about 32 major
groups, called phyla, of animals. During the next several laboratories, you will have the
opportunity to study how different animal groups are similar and how they differ. During
the lab, study characteristics that allow you to identify each group (or subgroup).
There are two main objectives for the following laboratories: 1) determine how different
phyla are unique and identifiable and 2) observe the similarities that allow us to group
animals together. Each lab will include some information about the animal groups,
which might otherwise be difficult to observe in the specimens available to you. Your
primary assignment each week will be to describe and draw the organisms you see.
NOTE: I will deduct points if you are making drawings directly from the photographic
atlas or other two dimensional materials. Drawings should be made from original
specimens and slides.
Some factors to consider when constructing a comparative chart of the animal phyla:
1) Type of symmetry and number of embryonic tissues: Does the organism’s body
have symmetry? If so would you consider it radial or bilateral? Does the embryo have
none, two (diploblastic) or three tissues (triploblastic)?
2) Cephalization: Is there a head end?
3) Mobility: does the animal move? If so, how? Are there appendages to aid in
locomotion? Describe these appendages.
4) Type of gut: Is the gut sac-like with one opening? Tube within a tube? Simple tube
that is unmodified? Tube that has accessory organs associated with it?
5) Circulatory system: Does it have specialized vessels? Is it an open system (blood not
entirely enclosed in vessels or closed (blood enclosed within vessels)?
6) Type of Gas exchange: Does each cell take care of gas exchange independently? Are
there specialized organs? What type of organs?
7) Excretory system: How does the animal rid itself of nitrogenous wastes, excess water
or salts?
8) Nervous system: Does the animal have a nervous system? Does it have a brain?
9) Support system: What does the animal use to support its tissues and body?
Bi 102 Sponges & Cnidarians 1
