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Perch Family- 
                      Percidae 
  Eighteen species of percids in five genera are known from Wiscon- 
sin. This does not include the greenside darter (Etheostoma blennioides),
which has been incorrectly reported from southeastern Wisconsin. In 
the United States and Canada, 130 species in 5 genera are known 
(Robins et al. 1980). 
  The percidae appear to have originated in Europe from some basal 
percoid family during the Cenozoic, and to have spread to North 
America through at least two separate invasions. Percids have been 
known from the Upper Cretaceous and Oligocene of Europe, and from 
the Eocene of North America. 
  The darters, all of which are of North American origin, exhibit the 
greatest evolutionary development. The three genera, Percina (30 spe- 
cies), Ammocrypta (7 species), and Etheostoma (89 species), represent a 
cline from the primitive to the advanced. 
  By using 45 characters involving pigmentation, squamation, biochem- 
istry, counts, and measurements, Page (1974) was able to develop a phy- 
logeny for the genus Percina. Percina has a system of uninterrupted head
canals and a complete lateral line (Page 1977). Ammocrypta is similar to
Percina, but shows a reduction in some species in the number of pores in
the head canal system. In the most advanced Etheostoma, the pores have 
been lost and the canals have become interrupted in the head canal and 
lateral line systems. Bailey and Gosline (1955) demonstrated the value of
vertebral counts in the taxonomy of the Percidae and their utility in as-
sessing relationships and deciphering phylogeny. 
  Members of the perch family are widely spread throughout Wiscon- 
sin. These are advanced fishes with ctenoid scales, and with the pelvic 
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