186 'U. S. BUREAU OF FISHERIES 



which the fish is taken ; yet the number and size of the ^ill rakers of 

 the fish determine to a great extent what forms are retained in the 

 ahmentary canal." 



Tlie blackliead has a lonj^ breeding season, spawning fish having 

 been observed at Fairport from the middle of May to early August 

 (Lord, 1927). The eggs are laid in masses on the underside of 

 stones, boards, or other objects, and are closely guarded by the male. 

 The young grow rapidly and mature in one year. This minnow is 

 capable of producing a large number of fish in a limited area, as 

 shown by the ])roduction in a small pond in 1928. Pond F 3, with 

 an area of 0.073 acre, was stocked on May 9 with 295 adult black- 

 heads. The pond was drained October 11 and produced 15,691 

 blackheads having a total weight of 26 pounds. This was at the 

 rate of approximately 215,000 fish or 356 pounds per acre. No food 

 other than fertilizer was added to the pond during the summer. 



It is evident that a minow with such possibilities should make a 

 good forage fish, but in our experiments with bass it has proved 

 inferior to the golden shiner. This is probably due chiefly to the 

 small size of the blackhead. Such small, soft fish fall an easy prey 

 to the bass, and even the adults are devoured by the larger fingerlings 

 before the summer is over. The result is that, even though the ponds 

 may be heavily stocked with brood minnows in the spring, the black- 

 heads are practically cleaned out before the ponds are drained in 

 the fall, and the bass, deprived of their favorite food, begin to prey 

 upon each other. There is some evidence that the blackhead may be 

 a desirable forage fish for use with crappie, but we have not yet had 

 an opportunity to try this combination on a sufficiently large scale 

 to warrant definite conclusions. 



Since the blackhead is so prolific and feeds to such a large extent 

 on i^lant material it will no doubt prove to be a valuable fish for 

 growing in ponds by itself. As previously mentioned, the blackhead 

 will thrive in almost any kind of a pond that is rich in vegetation, 

 no matter how small it may be. Every pond station should have 

 several ponds devoted solely to the propagation of forage minnows. 

 Unless this is done there is always danger of losing one's stock of 

 forage fish, since it not infrequently happens tliat practically every 

 minnow in the bass ponds is devoured before fall. Furthermore, it 

 is essential to have a supply of forage fish on hand for feeding to 

 the brood stock. An occasional meal of minnows will keep these fish 

 in much better condition than if they are fed only artificial food. 



As stated above, the golden shiner has proved to be the best forage 

 fish for bass of any that we have tried. It is superior in several 

 respects to other fish which have been used for this purpose, and 

 it is doubtful if there is any other species which combines in an 

 e(]ual degree the desirable qualities of an all-around forage fish. 

 The golden shiner has a very wide geographical distribution and 

 is abundant in suitable localities throughout its range. It is by 

 nature a fish of quiet and stagnant waters and consequently is per- 

 fectly at home in the ordinary fishpond. The young feed chiefly 

 on microscopic Crustacea and plankton alga3. As they grow older 

 vegetable material, consisting chiefly of algte, forms a larger per- 

 centage of their food, although even adults may feed on Crustacea 

 and insects to a considerable extent. 



