132 



BULLETIN OF THE BUREAU OF FISHERIES 



This species is represented in the collection by 43 specimens, ranging in length from 32 to 

 130 millimeters (1^ to 53^ inches). These were collected at the following localities: Borrow pit, 

 Itta Bena Road; slough at Browning; slough near Greenwood; Pelucia Creek; and a borrow pit at 

 Craigside. 



35. Lepomis incisor (Cuvier and Valenciennes) 

 Blue-gill; "Blue-nosed bream"; "Shiner bream" 



Pomotis incisor Cuvier and Valenciennes, Hist. Nat. Poiss., VII, 1831, p. 466. 



Many specimens of this fish were preserved. A very large degree of variation with respect to 

 the depth and the contour of the body, the length of the opercular flap, and color is evident among 

 the specimens collected. The depth, for example, varied from 1.85 to 2.7 in standard length in 

 44 specimens measured. The opercular flap in several rather large specimens was notably produced, 

 approaching, in that respect, the long-eared sunfish (megalotis). However, they have the longer 

 gill rakers and the long, pointed pectorals of the bluegill. It so happens that these particular 

 specimens were taken in a comparatively small body of water where both species occurred. Hubbs 

 (1926, p. 71) has reported a number of combinations of hybrids. It is possible, although not prob- 

 able, that the specimens with the long "ears" are hybrids. Other pronounced variations — as, for 

 example, the differences in the depth of the body and in color — also occur among the specimens 

 at hand, which are difficult to ascribe to the hybridization of local species and appear to be only 

 variations within the species. It seems probable, therefore, that the difference in the development 

 of the opercular flap, too, constitutes a variation within the species. 



The marked variation in appearance among fish of this species may be said to be reflected in 

 their feeding habits, as a wider range of diet appears to exist than for any of the other members 

 of this family. According to the contents of 42 stomachs examined, this species utilizes considerable 

 vegetation and appears to take much of its food from the substratum, but also feeds at the surface 

 and among the plants. Filamentous algae probably composed fully 50 per cent of the ingested 

 material, appearing far too frequently to have been taken incidentally in the capture of other food. 

 Quantities of pond snails, which seemed to be somewhat neglected by the other fish of the region, 

 also had been taken. May-fly nymphs, midge larvte, and a variety of other insects were commonly 

 present in the stomachs. Minnows appear to be taken rarely, even by the full-grown bluegill, 

 as only a single Gambusia was found among the 42 fish examined. The intestine was found to 

 vary from 60 to 78 per cent of the total length of the fish. 



This species appears to be the most prolific member of the sunfish family, as a female of 155 

 millimeters contained fully 12,000 eggs. It is said to be one of the most productive species and 

 is recommended as being of considerable value for pondfish culture. The female appears to attain 

 sexual maturity at an approximate total length of 90 millimeters. The spawning season evidently 

 is an extended one, probably reaching its height during the early summer. Forbes and Richardson 

 (1908, p. 259) report ripe fish for Illinois in May and June. No specimens taken in May are at 

 hand. Fish with well-developed gonads, however, were taken in June, July, and August. Two 

 hundred specimens, ranging in length from 14 to 172 millimeters (1J^ to 6% inches), were collected 

 at the following localities: Borrow pits, Grenada Road; slough at Browning; slough at Money; 

 Hadley or Allen Lake; and Roebuck Lake. 



36. Lepomis megalotis (Rafinesque) 



Long-eared sunfish; "Blue-nose sunfish"; "Nigger bream" 



Jchthelis megalotis Rafinesque, Ichthyologia Ohiensis, 1820, p. 29. 



This beautiful sunfish is not especially numerous locally. Adult males (120 millimeters long) 

 are remarkable on account of a large nuchal hump. The species is recognized by the long, black, 

 opercular flap, the moderate number (37 to 39) of scales in a lateral series, and the few (6) very 

 short gill rakers on the first arch. Published accounts state that this species has no black spot 

 at base of last rays of dorsal. Some of the specimens in the present collection, however, have an 

 indication of such a spot. 



