PEARLY FEESH-WATER MUSSELS 83 



SESSIONAL PAPER No. 38a 



supply of the mussels is by no means fully dependent on tlie free-swimming organisms, 

 and that the favourable localities, discussed above, are largely conducive to the develop- 

 ment of the mussel on account of conditions favouring the deposition of the " detritus." 



RESTOCKING AND STOCKING. 



The restocking of areas where mussels at present exist, and where active fishing 

 is going on, and the stocking of new areas, may be summed up under the head of 

 artificial propagation. As the method pursued in artificial propagation has been 

 described in a general way, we shall now consider its application to the river in 

 question. 



Of all mussels so far experimented with, L. luteola lends itself most readily to arti- 

 ficial propagation on a commercial basis. It is the species chiefly propagated at 

 present by the United States Government. As time and opportunity prevented my 

 making an extensive survey of Grand River, I cannot state the extent to which this 

 species occurs therein. It is, nevertheless, very generally distributed in Ontario 

 waters, but in order to attain to a size and abundance suitable for commercial value it 

 apparently must have the conditions more or less as described above in " river-lakes." 

 The specimens so far obtained from the river are not of very good quality. This is 

 probably due to unfavourable conditions preventing their optimum development in the 

 areas from which they come. In a commercial appraisal made of some of our shells 

 by Mr. John B. Southall, Shell Expert at the Fairport Station, this particular shell 

 was reported on as follows:^ "medium size, no discoloration, brittle, third grade- and 

 yielding 788, 16 — line,^ gross blanks per ton." In his remarks he further states that 

 they were rather thin and of a steel-coloured nacre and produced blanks that would 

 chip and cleave during the processes of button manufacture. 



With regard to this mussel I would suggest a careful examination of the areas 

 lying behind the larger dams with a view to stocking them with the valuable species. 

 Such a survey might include the dams at Dunville, Caledonia, Brantford and Gait 

 on the main river, and also the larger ones on the Speed tributary, where the fall is 

 well utilized, and where clams of good size are said to be found in all such storage 

 basins as hold back water over a considerable area. Behind the dam at Caledonia 

 there is a stretch of practically dead water for twenty miles which might lend itself 

 favourably to the development of this mussel. Here the river bed can be classed as 

 permanent, inasmuch as the usual freshet velocity of the river water above is greatly 

 reduced on reaching this point. At Brantford the old barge canal, described above, 

 containing also Mohawk lake, might prove a very suitable locality for propagation 

 on a small scale. For the purpose of stocking, I would strongly recommend that an 

 attempt be made to introduce the particularly fine luteolas of lake Pepin, in the 

 Mississipi, about 30 miles down the river from St. Paul, Minn. In the United States 

 gravid mussels, for purposes of infection, have not been shipped over a much greater 

 distance than 300 miles, but I am informed by the Director of the Fairport Station 

 that they sent a couple of shipments of live mussels from Fairport to New York in 

 the fall of 1916, and that the majority reached their destination in good condition. 

 The distance from lake Pepin to Gait, Ont., would be about 835 miles by rail. 



Fortunately, this species is not very exclusive in its choice of hosts, neither is 

 its spawning period of short duration, as is the case with some other commercial 

 mussels. All the Lampsilinae, in fact, are gravid, more or less, during the whole year 



1 In the report of the appraisal the luteolas sent from the Canada Co. Cut and from the 

 Grand River were combined in one report. 



2 In grading the material I sent him, the texture and lustre of the niggerhead iQ. ebenus) 

 was taken as the standard. 



3 A line in biitton measurement is 1/40 of an inch. 



