Zoology 511
Lab 2
Lab 2 - Fish Evolution
Goals:
 To understand phylogenetic and morphological trends in fish evolution.
 To identify major groups of extant fishes and to recognize their characteristics.
 To identify Wisconsin fishes to the family level.
Readings
Gilbert, C.R. 1993. Evolution and Phylogeny. In The Physiology of Fishes (D.H. Evans, Ed.). pages 1-35
Comparative Anatomy:
Examine the following specimens for the traits described in the lecture that mark major advances in fish
evolution:
sea lamprey (Petromyzontiformes, Petromyzontidae, Petromyzon marinus)
lake sturgeon (Acipenseriformes, Acipenseridae, Acipenser fulvescens)
longnose gar (Lepisosteiformes, Lepisosteidae, Lepisosteus osseus)
bowfin (Amiiformes, Amiidae, Amia calva)
alewife (Clupeiformes, Clupeidae, Alosa pseudoharengus)
brook trout (Salmoniformes, Salmonidae, Salvelinus fontinalis)
largemouth bass (Perciformes, Centrarchidae, Micropterus salmoides)
List the major differences in external anatomy between the following pairs of fish.
sea lamprey-lake sturgeon:
lake sturgeon-longnose gar:
longnose gar-bowfin:
bowfin-alewife
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Zoology 511
Lab 2
alewife-brook trout:
brook trout-largemouth bass:
Wisconsin Fish Families:
Using the Becker key provided, practice identifying fish to the Family level. You will use this
information for Assignment #1, described below.
QUESTIONS: Answer the following and turn in next week
1. Which is the derived character state, lungs or swimbladder?
2. Although the majority of water on earth (97%) is oceanic water, salt-water species only comprise
roughly 58% of all fish species. Speculate why this is so.
3. Riddle: How can a fish “tell” you what it eats?
Assignment #1.
Due at the beginning of class on Feb 14/15
The Becker key can be laborious to go through. This is mostly because it is a dichotomous key, i.e. for
every key feature there are only two branches. A simpler key can have multiple branches at every point.
For example, a good starting point might be: 1) soft-rayed fishes without adipose fin, 2) soft-rayed fishes
with adipose fin, 3) spiny-rayed fishes.
For this assignment, create your own family key. Make use of the basic morphological differences between
families (e.g. fins, spines, scales, tails, mouths, snouts, etc.) to design your key. You can have as many
branches at each point as you wish, but keep in mind that the goal of this exercise is to make keying fish
families easier. Full credit will be given to a key is correct, and is not a blatent plagiarization of Becker's
key.
In your key, include the 26 families that we will work with this semester. The families are:
Petromyzontidae, Acipenseridae, Polyodontidae, Lepisosteidae, Amiidae, Clupeidae, Anguillidae,
Hiodontidae, Cyprinidae, Catostomidae, Ictaluridae, Salmonidae, Esocidae, Umbridae, Osmeridae,
Percopsidae, Aphredoderidae, Lotidae, Fundulidae, Atherinidae, Gasterosteidae, Cottidae, Moronidae,
Centrarchidae, Percidae, and Sciaenidae.
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