ANNOTATED LIST OF FISHES 



115 



respect to this character ranged from 225 to 400 millimeters in length, and the smallest of these had 

 55 and the largest 51 gill rakers, whereas a specimen 305 millimeters long had only 38. These 

 counts do not suggest a variation with age but a rather large difference among individuals. 



With reference to the size attained locally, the gourd-head buffalo is intermediate of the other 

 two species of buffalo fish recorded in this report and was less frequently taken than either of them. 

 It is quite common, however, and is a valuable food fish. 



An examination of 25 stomachs of all three species shows an appreciable difference in the feeding 

 habits, and their divergence in form may be correlated with this factor. 



The gourd-head buffalo, according to six stomachs examined, depends upon the minute plankton 

 crustaceans and, to a less extent, the free-swimming insect larva for the basis of its diet, in this respect 

 closely resembling the spoonbill catfish. These two fish were the only ones that had utilized the 

 almost transparent midge larva? Corethra. Vegetation was used sparingly. Forbes and Richardson 

 (1908, p. 70) found about a third of the stomach contents in 17 specimens examined to consist of 

 vegetable matter and the other two-thirds consisted of aquatic insects and Entomostraca. 



The large mouth and well-developed gill rakers (which are fully twice as numerous as in the two 

 related species herein considered) seem well adapted to obtaining this type of food. A muscular 

 expansion of the stomach forms a sort of gizzard, and the intestine is relatively long, being almost 

 three times the length of the fish. These structures would suggest a vegetable diet greater than has 

 been shown by the stomachs examined. 



The reproductive organs in six specimens taken during the summer and fall were all in a col- 

 lapsed condition. The spawning period is reported to occur during the early spring (Forbes and 

 Richardson, 1908, p. 70). 



A deep slough at Browning was well stocked with this species, and it was collected in a borrow pit 

 and in a slough at Money, in Hadley or Allen Lake, Roebuck Lake, and in a lagoon near Lake 

 Mclntire. 



8. Ictiobus bubalus (Rafinesque) 

 Small-mouth buffalo; Razor-back buffalo; Quill-back buffalo 



Amblodon bubalus Rafinesque, Journal Physique, 1818, p. 421. 



This species is represented in the collection by 22 specimens, ranging in length from 160 to 

 370 millimeters (614 to 14^ inches). It is characterized chiefly by the high, compressed back and 

 long, falcate dorsal fin, the last-mentioned character giving origin to the name "Quill-back." Other 

 characters are shown in the key. 



This is the smallest and probably the least important, economically, of the three buffalo fish 

 collected in the vicinity of Greenwood. Although this species is reported in some sections of its 

 range to reach a weight somewhat less than 40 pounds, the largest one taken locally during the 

 summer weighed only 3 pounds, and the average was much smaller. 



Disintegrating, darkened plant fragments were estimated to constitute fully 80 per cent of 

 the diet, with the remainder usually consisting of copepods and midge larvse in 8 stomachs examined. 

 The inferior mouth and straightened ventral line characterize it as a bottom feeder. It has a 

 less effective straining apparatus than J. cyprinella, as its gill rakers are not quite as long and only 

 about half as numerous. The intestine approximates two and one-half times the length of the body, 

 placing this fish intermediate in this respect of the other two buffalo fish collected locally. 



The spawning season in the south is said to occur during March and April. The specimens 

 examined, all of which were taken during the summer, had passed the spawning period. This 

 species was collected in a slough at Browning, Roebuck Lake, Mossy Lake, and in a slough near 

 Sidon. 



9. Ictiobus urus (Agassiz) 



Mongrel buffalo; "Rooter"; "Liner" 



Carpiodes urus Agassiz, Arner. Journ. Sci. Arts, XVII, 1854, p. 355. 



This species is represented by 15 specimens, ranging from 225 to 420 millimeters (9 to 16^ 

 inches) in length. It is characterized principally by the low, rounded back, convex ventral outline 

 the moderate mouth (which is protractile, forward and downward), and the less strongly falcate 

 dorsal fin as compared with the other species. These differences are recognized by local fishermen. 



