72 
Burr, Kuhajda, Dimmick, and Grady 
Life History 
Age, Maximum Size, and Weight-Length Regression. Specimens 
(32-99 mm SL; N = 10) aged from pectoral spines were 1 to 4 years old. 
Accurate readings of other pectoral-spine cross sections could not be 
made. The largest specimen aged was 99 mm SL and 4 years old. The 
largest male examined was 101 mm; the largest female 98 mm. Few 
individuals reach 85 mm. The largest specimen recorded by Taylor 
(1969) was 100 mm SL. 
Length-frequency histograms of 248 specimens were difficult to 
interpret, although several age classes appear to be represented (Fig. 5). 
Populations seem skewed towards younger age classes as would be 
expected in a healthy population experiencing normal recruitment. The 
relatively large number of individuals collected in May under 40 mm SL 
indicates that growth is slow in winter and early spring. In September 
(N = 92), age 0 fish ranged in SL from 17 to 47 mm, age 1 from 49 to 67 
mm, age 2 from 71 to 76 mm, and ages 3 to 4 from 79 to 86 mm. There 
was considerable overlap in length of older age classes. Lack of adequate 
sample sizes in most months precludes more meaningful comparisons of 
age classes and sexual differences in growth. 
Regression of body weight on length of specimens was similar for 
both sexes. The relationship between adjusted body weight in grams 
(W) and SL for males was Log W = -5.098 + 3.198 Log SL (r = 0.99; N = 
56) and for females was Log W = -4.631 + 2.918 Log SL (r = 0.99; N = 
77). 
Age and Size at Maturity. Females of N. furiosus reached 
reproductive maturity in a minimum of 2 years, although a vast ma- 
jority of gravid females were 3-year-olds (x = 3.1 years; Table 1). 
Other species of Noturus about the same size as N. furiosus reached 
reproductive maturity in 1 to 2 years (e.g., N. exilis, Mayden and Burr 
1981; N. miurus, Burr and Mayden 1982a; N. nocturnus , Burr and 
Mayden 1982b). Mature females ranged in SL from 61 to 98 mm (x = 
74.8; N = 16 for individuals 2 to 4 years old) and in adjusted body 
weight from 4.82 to 17.85 g (x = 7.60; N = 16). No females older than 4 
years or longer than 98 mm SL were seen. 
Age at first spawning for males was not ascertained, although all 
males found guarding nests or nest sites were 2 to 4 years old and longer 
than 60 mm SL. Adjusted body weights of all males in breeding 
condition ranged from 3.81 to 18.24 g (x= 8.46; N = 24). 
Reproductive Condition in Males. In gross appearance, testes were 
opaque white and fimbriate as in other ictalurids (see Sneed and 
Clemens 1963; Mayden and Burr 1981). Weight of testes was positively 
correlated with increasing body weight. For combined samples of 
immature and mature males, linear regression of testes weight in 
