Lab Report: Vertebrates I
Lab day and time: ____________ Name ________________________
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Objectives
Recognize the characteristics that all vertebrates share
Understand the diversification of the vertebrates
Learn the four major groups of fishes and their characteristics
Be able to describe the major adaptations of fishes
Understand the theory for the water-land transition of vertebrates
Describe the diversity of amphibians
Introduction to the Subphylum Craniata
Vertebrates are a group of animals that share characteristics with other chordates: notochord,
dorsal hollow nerve cord, pharyngeal slits and a post-anal muscular tail. All four chordate
features are usually not present in the adult stage of the vertebrates, but are found in the
embryonic stages. Vertebrates, however, have a major innovation not shown at any stage in other
chordates (the Urochordata and Cephalochordata), the brain case or cranium. This structure
encloses a brain in cartilage or bone. While the group is named for the vertebral column
enclosing the nerve cord, some vertebrates do not show this trait (e.g. hagfish and lampreys). In
addition to an endoskeleton of cartilage or bone which provides structural support, vertebrates
also have various sensory organs at the head end, a muscular pharynx for pumping water (in
fishes), and a closed circulatory system with a pumping organ, the heart, which has two to four
chambers. The classes of Vertebrates are: Myxini (hagfishes), Petromyzoniformes (lampreys;
these two classes make up the superclass Agnatha), Chondrichthyes (cartilaginous fishes),
Osteichthyes (boney fishes), Amphibia (frogs & salamanders), Reptilia (turtles, lizards, snakes &
crocodilians), Aves (birds), Mammalia (mammals). We will look at the fishes and amphibians
today.
Activities
Shape of Life: Bones, Brawn and Brains
What adaptations did fish evolve to become dominant in the seas?
What feature allowed fish brains to become larger?
Bi102 Vertebrates I: Fishes 1
