12 



MINNOWS GAMBUSIA AFFINIS AND CYPRINODON VARIEGATUS. 



is less than 3 months old or not until the fish is 1 year old; it may 

 appear when the fish is 13 mm. in length, or be delayed until a length 

 of 23 mm. is attained. 



9. The proportion of males to females appears to be about 1 to 8 

 or 9. 



10. Some of the individuals of the early broods of the season 

 become sexually mature and produce small broods of young late in 

 the season in which they themselves were born. 



CYPRINODON VARIEGATUS (Lacepede). THE VARIEGATED MINNOW. 



This variegated minnow occurs on the Atlantic coast from Cape 

 Cod to the Rio Grande, inhabiting brackish waters and ascending 

 streams. Stragglers are also taken in strictly salt water. Locally 



Fig. 3. — Cyprinodon variegatm. Variegated minnow. Male. 



it is very abimdant in the shallow brackish ponds, but it does not 

 appear to attain as large a size as it docs in some other locahties. 

 The usual length of the adult female is only about 45 mm. ; the adult 

 male is somewhat larger, averaging about 48 mm. in length and 

 being notably deeper in body than the female. The sexes appear to 

 occur in equal proportion. 



The fish is an active swimmer and very ferocious. In captivity it 

 will kill and devour fishes of other species much larger than itself. 

 Even such species as Fundulus heteroclitus (Linnaeus) and Fundulus 

 majalis (Walbaum), which are ordinarily quite aggressive, are unable 

 to withstand its attacks. Its sharp, tricuspid teeth afford a very 

 effective weapon. It makes its attacks by darts, inflicting a wound 

 here or there, and then quickly turning for defense. After a brief 



