LAMPREYS AND FISHES OF INDIANA. 249 



Genus APHREDODERUS LeSueur. 



Premaxillaries not protractile. Mouth of moderate size. Lower jaw 

 projecting. Gill-rakers short. Gill-membranes joined to isthmus. Bran- 

 chiostegals six. Vent of the adults jugular. 



Aphredoderus sayanus (Gilliams). 



Pirate Perch. 



Jordan and Gilbert, 1882, <S, 460; Blatchley, W. S., 1885, 1, 136. 



Body compressed, the depth in the length about three times. Head 

 large, thick, three times in length to caudal. Cheeks, opercles, and oc- 

 ciput covered with scales. Mouth moderate, somewhat oblique, maxil- 

 lary reaching to perpendicular from the front of the eye. Scales strongly 

 ctenoid, forty to fifty-eight in a longitudinal row; about thirty in a 

 transverse row. Dorsal rays III, 10 or 11. Anal rays II, 5 or 

 6. Vent ©f the adults just behind the isthmus, that of the younger 

 fishes somewhat further back. Color dark to pale olive, with numerous 

 minute dots of bluish. Sometimes there is a streak of brown above the 

 anal fin. Length about four inches. 



Illiaois River specimens have the color paler, the scales smaller, about 

 fifty-eight along the side. Dr. Jordan regards them as forming a dis- 

 tinct sub-species, the gibbosus of LeSueur. Wabash River specimens show 

 forty-eight to fifty-one scales (4, '88, 116). 



Distributed from Louisiana to S. Dakota, Minnesota, and Lake Erie. 

 In Indiana it has been put on record from the following localities : Wa- 

 bash River (.9, 9, 49); Monroe County (1, '85, 411); Maiimee River at 

 Keudallville (i, 77, 44) ; Brown County (i?-i, '84, 204); Kankakee River 

 at Plymouth (4, '88, 156); Whitley County (^, '88, 159); Wabash, 

 Maumee and Calumet rivers (1-J, '77, 101,); Calumet River (7^, No. 2, 

 49); Eel R. basin (4, '94, 38); Posey and Decatur counties (;?^, '93, 96); 

 Winamac. 



This species is an inhabitant of sluggish and grassy streams, and is, 

 therefore, to be found in swampy regions. Its food consists of small 

 crustaceans, the larvse of aquatic insects, and occasionally some of the 

 smaller fishes (14-, No. 2, 77). One of the most peculiar things apper- 

 taining to this fish is the gradual change which the position of the vent 

 undergoes during the growth of the fish. Jordan states that when the 

 fish is an inch in length the vent is opposite the middle of the ven- 

 trals. When two inches long, it has moved forward to between the bases 



