THE FAIRPORT FISHERIES BIOLOGICAL STATION. 4OI 



ature of water, the number and size of fish, and the activity of the glochidia. The 

 fish may remain exposed to the glochidia for a period of 5 to 20 minutes. From time to 

 time a specimen of fish is taken by hand, or with a small hand net, and the gills exam- 

 ined to ascertain if a sufficient degree of infection has obtained. When, in the judg- 

 ment of the operator, the fish show the optimum degree of infection they are ready 

 for liberation. 



(4) Using buckets or small nets, the fish are transferred from the tank back into 

 the river or the entire tub may be turned over into the river. This concludes the 

 operation of infection as ordinarily carried on in a practical way. 



INVESTIGATIONS RELATING TO PROPAGATION. 



A good deal of experimental work is being carried on at the station to determine 

 what species of fish are best suited for certain species of mussels, to ascertain the period 

 of parasitism and the life history of the young mussels after parasitism, and to lead to 

 such improvement of methods as will make the work most productive of practical 

 results. 



In addition to the study of special problems of importance, three general lines of 

 investigation have been carried on practically continuously. These are (i) the daily 

 collection of fish from the river for study of the condition of natural infection, (2) experi- 

 ments in artificial propagation, employing various species of mussels and fish and keep- 

 ing careful observation of the methods and results, and (3) the study of the habits and 

 distribution of juvenile mussels. The results have been so favorable as to justify the 

 continuance of these studies for a considerable time. 



The fishes of the sunfish family, game fishes, such as the bass, crappie, sunfish, etc., 

 are usually used for the mucket {Lampsilis ligamentimi) and the fat mucket {Lampsilis 

 luteola). For a very important mussel, the pimple-back {Quadrula pustulosa), the Silu- 

 ridae, or catfishes, are found to be best suited. One of the best species of mussel, the 

 "niggerhead" {Quadrula ebenus), is known to become parasitic only upon one species 

 of fish, the river herring, Pomolobus chrysochloris. This fish is so delicate that it has 

 been impossible to handle it in a practical way, and, therefore, no operations in the 

 propagation of this mussel are yet pursued. Some experiments have been conducted 

 which are promising of success. Examples of the herring found during the breeding 

 season of the "niggerhead" are usually so heavily infected that it may not be necessary 

 to use artificial methods with this mussel, although the abundance of the fish should 

 be promoted. The matter is now under investigation. A very valuable species of 

 mussel, the yellow sand-shell {LM-mpsilis anodontoides), is parasitic upon the several 

 species of gar. 



Other investigations are now being conducted with reference to the possibility of 

 rearing young mussels after parasitism in ponds or in floating crates, and the preliminary 

 results are as encouraging as could be expected. It is interesting to note that from 

 glochidia of commercial species of mussels artificially infected upon fish at this station, 

 young mussels have been reared within a period of two years to such a size that it 

 was possible to cut and finish buttons from the shells (pi. lxxx). Some of these were 

 reared in floating crates and some in one of the larger earth ponds. They are not only 

 the first mussels to be reared to such a size from artificial infection, but they are the 

 first commercial forms known to have grown in ponds. The experiments have not yet 



