130 



BULLETIN OF THE BUREAU OF FISHERIES 



water, the alimentary canal was almost empty, as only a few insects (back swimmers), fragments 

 of insects, and very few copepods and ostracods were found. Gambusia, one of the chief foods, 

 locally, of the crappies, was absent in this pond. 



32. Chaenobryttus gulosus (Cuvier and Valenciennes) 



Warmouth bass; "Spotted bbeam" 



Pomotis gulosus Cuvier and Valenciennes, Hist. Nat. Poiss., HI, 1829, p. 498. 



This is one of the common sunfishes at Greenwood, being exceeded in abundance only by 

 the bluegill sunfish and by the white and black crappies. Its large mouth, the maxillary reaching 

 past the middle of the eye, and the presence of teeth on the tongue distinguish it from related 

 species occurring locally. In structure, the specimens at hand are fairly uniform, but in color 

 there is much variation, both with age and among individuals of the same size. The young of 

 about 3 inches and less in length have indefinite crossbars and no indications of dark spots on the 

 scales that form longitudinal lines in adults. The dark stripes on the cheeks, usually quite evident 

 and distinctive of the species, occasionally are wanting, and some individuals are much more 

 definitely spotted than others. 



The fin rays appear to be remarkably constant, for in 18 specimens examined, the dorsal fin 

 had 10 spines in 15 specimens, 9 in 2 specimens, and 11 in only 1 specimen. The soft rays num- 

 bered 10 in all except one specimen, which had 11. In the same specimens the anal fin constantly 

 had 3 spines and 9 or 10 soft rays. 



The warmouth bass, although entirely carnivorous, has a notably varied diet, as shown by 

 the contents of 18 stomachs, depending largely upon insects, however. The water boatman, 

 Corixa, and whirligig beetles frequently are taken. Crustaceans, including the shrimp Palsemo- 

 netes exilipes, were next in frequency, with small fish less evident than either of these groups. 

 The intestine approximates one-half the total length of the fish. 



The reproductive period appears to be an extended one, as ripe fish were taken through June, 

 July, and August. Sexual maturity seems to be reached at a comparatively small size, as a female 

 only 85 millimeters in length contained well-developed roe. A fish 124 millimeters in 'total length 

 contained approximately 4,000 nearly mature eggs, and larger individuals probably produce a 

 proportionately larger number of eggs. 



The 54 specimens in the collection range from 52 to 178 millimeters (2 to 7 inches) in total 

 length and were collected at the following points: Borrow pit, Itta Bena Road; borrow pits, Grenada 

 Iload; slough at Browning; slough near Greenwood; Hadley or Allen Lake; borrow pit at Craigside; 

 and in a drainage ditch at the Tallahatchie compress. 



33. Centrarchus macropterus (Lacepede) 



Round sunfish; "Sun perch" 



Labrus macropterus Lae4pede, Hist. Nat. Poiss., Ill, 1802, p. 447. 



This little sunfish is quite unimportant as a food fish and is not very numerous locally. The 

 numerous anal spines and rays (the usual number being VIII, 14), the short, round body, and the 

 dark stripes along the rows of scales serve well to separate it from the other sunfishes. 



Among the members of the sunfish family (Centrarchidse) occurring in the present collection, 

 the round sunfish is the best adapted for the utilization of the plankton crustaceans through its 

 increased number of gill rakers. This species and the crappies were the only representatives of 

 the family that made use of the minute crustaceans after the fish had reached the "adult stage," 

 and under normal conditions the mature crappies apparently also ignored this type of food. The 

 following table shows the wide variation in the number and length of the gill rakers that exists 

 among the local representatives of this family. 



