ORANGE-SPOTTED SUNFISH, LEPOMIS HUMILIS. 7 



have been observed raiding the nests of humilis, particularly when 

 the males of the latter species were engaged in fighting off their own 

 kind. 



The period of incubation for the eggs of the orange-spotted sun- 

 fish has been observed to be five days, with the water varying in tem- 

 perature between 65 and 70° F. The newly hatched fry measures 

 1 cm. in length. The number of eggs laid each season varies directly 

 with size and age of the female. The maximum number of eggs 

 found in any of the females collected from the FairjDort reservoir is 

 4,700. This count was for a fish 10.5 cm. long (about 4 inches), 

 taken in early June. The smallest fish found carrying ripe ova was 

 3 cm. long (about li inches). It was taken August 3 at Fairport 

 and carried 175 eggs. The following table (2) indicates the increas- 

 ing fecundity of the species as the size of the female increases. 



Table 2.- 



-Ot'fl. counts of Lepomis humilis of different lengths collected in Iowa 

 and Louisiana from April through Augtist. 



GROWTH AND ATTAINMENT OF SEXUAL MATURITY. 



The rate of growth of the orange-spotted sunfish, as indicated by 

 scale examinations, differs considerably in representatives of this 

 species from Louisiana and Iowa. The earlier breeding season and 

 the longer feeding and growing period in Louisiana (Table 1 and 

 Fig. 1) make the southern fish somewhat larger than an Iowa speci- 

 men of the same age. The annuli of the scales of Lepomis humilis 

 are very satisfactory indicators of age. The annuli, particularly of 

 northern fish, stand out very plainly. The information at hand on 

 the growth of the sunfish has been obtained through a study of the 

 scales of 180 examples from Louisiana captured in each month from 

 March to November, inclusive, and of 389 individuals taken in Iowa 

 during a similar period. Although no observations are available on 

 the actual growth of a single specimen over an extended period of 

 time, a more accurate knowledge of the average growth of the species 

 has been obtained by the study of the scales. Tlie fish considered in 

 this connection were measured and determinations were made of sex 

 and of ripeness, judged particularly in the females by the condition 

 of the contents of the ovaries. A number of scales of each fish taken 

 from a point just posterior to the insertion of the pectoral fin were 

 examined to ascertain the growth season of the specimens. 



Table 3 gives the number of fish of various ages examined and their 

 average mean lengths by months. Both Louisiana and Iowa collec- 

 tions are included. 

 23424 °-23 2 



