Age, Growth, Food Habits, and Reproduction of the 



Redline Darter Etheostoma rufilineatum (Cope) 



(Perciformes: Percidae) 



in Virginia 



James C. Widlak and Richard J. Neves 



Virginia Cooperative Fishery Research Unit 1 , 



Department of Fisheries and Wildlife Sciences, 



Virginia Polytechnic Institute and State University 



Blacksburg, Virginia 24061 



ABSTRACT. — Life history aspects of Etheostoma rufilineatum, the 

 redline darter, were investigated from May 1981 to May 1982 in the 

 North Fork Holston River, Virginia. Analysis of scale samples indi- 

 cated that males and females grew at approximately the same rate, but 

 males reached a greater maximum length. Estimated annual survival 

 rate for age II and older males was 0.28 and for females 0.03. Aquatic 

 insect larvae were the major food items, and dipterans predominated 

 numerically (68-87%) year-round. Feeding over a 24-hour period 

 peaked from early to late afternoon (1600-2000 hr). The sex ratio 

 favored males throughout the year (2.5:1) and was attributed to differ- 

 ential survival and distribution. Age I fish more than 42 mm long, of 

 both sexes, were sexually mature. Ripe males were first collected in 

 March, although spawning coloration was evident in December. Female 

 ovaries began maturing in late February, and spawning occurred from 

 mid-May to mid-August. 



INTRODUCTION 



The darters are small members of the family Percidae and consti- 

 tute a diverse group of North American fishes, with 145 species in 3 

 genera and 28 subgenera (Collette 1967; Page 1983). They reach maxi- 

 mum lengths of 35-200 mm and differ widely in morphological charac- 

 teristics, habitat preference, and behaviors. A comprehensive review of 

 the biology and ecology of darters was published by Page (1983). 



The redline darter, Etheostoma rufilineatum (Cope), is one of 13 

 species in the subgenus Nothonotus, one of the more gaudy groups of 

 darters. Nothonotus species exhibit strong sexual dimorphism. Males of 

 most species display brilliant coloration during most of the year. The 

 species occur in riffle habitats of clear upland streams. Most occupy the 



'The Unit is jointly supported by the U. S. Fish and Wildlife Service, the 

 Virginia Commission of Game and Inland Fisheries, -and Virginia Polytechnic Insti- 

 tute and State University. 



Brimleyana No. 11:69-80. October 1985 69 



