Cottus Life History in Delaware 



77 



160- 



140 



120- 



« 100 



LU 



CO 



s 



D 



Z 80- 



< 

 > 

 O 



601- 



40- 



20- 



10 20 30 40 



STANDARD LENGTH (mm) 



50 



Fig. 3. Relationship between number of mature ova and standard length of 

 Cottus bairdi from Butler Mill Branch, Sussex County, Delaware. 



between two sampling periods, in which there also was no significant 

 difference in size of adults. 



Hann (1927) generalized that fecundity in C. bairdi is approximately 

 proportional to the cube of the female's length. This is in agreement with 

 relationship, Log F = -2.738 + 2.962 Log SL, observed by Ludwig and 

 Norden (1969) in Wisconsin. Their fecundity-length relationship is higher 

 than that observed by us for all Butler Mill Branch females examined: 

 LogF= -2.129 + 2.608 Log SL. 



The regression equation for the relationship of ova number (Y) to 



