Relative 

 frequency. 



August 15 7.9 



August 20 22.5 



September 12 23. 4 



September 26 13.8 



November 15 26.2 



December 7 20.1 



10 U. S. BUREAU or FISHERIES. 



pend so much on size or season as it does on actual age measured in 

 terms of favorably temperatured days for feeding and growth. This 

 is substantiated bv the fact that the large majority of fish beginning 

 their third growth year, though in actual calendar days not 2 years 

 old, are spawning fish in the May of that growth year. The presence 

 of the relatively few late breeders of the second growth j^ear prob- 

 ably tends toward a lengthening of the breeding season in the third 

 and fourth growth years, though this question has not been verified 

 by observation on a given second-growth-year breeder. It is known, 

 however, that all the breeding sunfish for a given year do not become 

 ripe at the same time in early spring. 



Data supplementing this observation of extended breeding period 

 are at hand in the form of the following frequency records of Lepo- 

 mis humilis collected from May to December, 1918, at Mound, La. : 



Relative 

 frequency. 



May 9 0.1 



May 25 .09 



June 8 13.9 



June 20 12.6 



July 5 3.4 



July 18 .7 



August 5 4.0 



The appreciable increase in relative frequency of the species, as 

 indicated for collections in June, is, without doubt, due to the early 

 spring production resultant from the spawning of fish in the third 

 or later growth years. The large production indicated as occurring 

 in August (the increased frequency being noted for late August and 

 for the remainder of the year") is resultant from the spawning of 

 2-year-old fish and of others of greater age whose breeding period is 

 late in summer. The marked decrease in relative frequency noted 

 during July and early August is due, there seems little doubt, to 

 the utilization of humilis as food by larger carnivorous fish during 

 the usual period of low-water stage with resultant concentration of 

 fish and loss of protective shallows. 



Lepomis Jiumilis reaches a length of at least 11.2 cm. (about 4^ 

 inches) and an age of 7 years, probably more. The large number 

 of circuli representing the annual growths of the fifth, sixth, and 

 seventh years and their very large size quite obliterate the earlier 

 annuli and make it impossible to accurately determine the age of a 

 full-grown sunfish of this species. However, in Eupomotis gJhhosus^ 

 the age of an adult 11.2 cm. or more in length may be quite easily 

 determined. The difference lies probably in the faster early growth 

 of (/ihhosus. 



FOOD. 



Information regarding the food of Lepomis humilis is available 

 through the records of stomach examinations of examples of this 

 species collected at Mound, La., on the occasion of the study of the 

 effectiveness of Gambusia and other small fishes as mosquito-control 

 agents. The records here tabulated (Table 4) are given by aver- 

 aged estimated percentages of the food organisms ingested. It is 



* Collections were made by using J-inch me.^h seine, which allowed all humilix under 

 an inch long to pass through. This is the reason for the increased frequency coming 

 about a month after the spawning, as in the spring. 



