Becker, George C. / Fishes of Wisconsin
Keys to the fishes of Wisconsin, pp. 63-170 PDF (22.5 MB)
Keys to the Fishes of Wisconsin Structure and Use of the Keys Taxonomic keys are artificial devices. Species did not evolve from keys; rather, keys are man-made constructions designed to help in the identification of dif- ferent species or forms. The keys in this book are dichotomous; that is, the characteristics are grouped in pairs or couplets of contrasting statements. The user of the key chooses the statement which applies to the fish being identified, and then proceeds to the next couplet indicated. As inapplicable statements are progressively elimi- nated, it will eventually be possible to give the correct species label to the speci- men. The first of the keys that follow is the Key to the Families. Ten species in Wisconsin are the sole representatives of their families in the state. For these fishes, the family name is given, and a reference to the page in the book where the main species account is found. The families for which this occurs are the following: Paddlefishes, Bowfins, Freshwater Eels, Smelts, Mudminnows, Pi- rate Perches, Trout-perches, Codfishes, Silversides, and Drums. As an example, if the specimen keys out at 12a (PIRATE PERCHES, Aphredoderidae), the user of the key is referred directly to the pirate perch account on page 733 in the main text. All other families of Wisconsin fishes are represented in the state by more than one species. For fishes in these 16 families, the family name is given, and a reference to a separate key to that family. These keys follow the Key to the Families. For instance, if the fish that is being keyed out is a minnow, the user of the key will be directed at 21a in the Key to the Families to a separate key- Key to the Minnows and Carps (page 107). In this key the 45 known species of Wisconsin minnows and carps are separated out and identified to species, and after careful searching it should be possible to arrive at the common and scien- tific names for the minnow specimen and the page number for that species 63
http://rightsstatements.org/vocab/InC/1.0/| Copyright 1983. The entirety of this book is available for viewing by the public as an Open Access text through the cooperative efforts of George Becker, the University of Wisconsin Press, and the UWDCC. This Work is copyrighted to the Board of Regents of the University of Wisconsin System. Any use of this material falling outside the purview of "Fair Use" requires the permission of the University of Wisconsin Press.