552 



BULLETIN OF THE BUREAU OF FISHERIES 



nothing to indicate that the pilot were caught in 20 fathoms also, but it need not 

 be ignored when supported by the preceding record. A box (2,250 feet) of nets of 

 2 % -inch mesh lifted with a whitefish gang in 15 fathoms on September 17, 1917, 

 caught 27 fish of this species. On September 26, 1917, a box of nets in 17 fathoms 

 had 29. On September 24, 1917, a gang set from the can buoy in Thunder Bay to 

 Sulphur Island in 8 to 10 fathoms got 600 pounds three nights out. 



Thus all the records indicate that the pilot begin to move inshore in numbers 

 on honeycomb rock and gravel about the middle of October, and that they remain 

 there until the nets are pulled in. Since few gill nets of a mesh suitable for pilot are 

 set in the spring, not much is known about the offshore movement. The depth to 

 which the fish migrate in summer is certainly not over 30 fathoms and probably not 

 over 20. At depths of 10 to 24 fathoms I took specimens off Alpena on September 

 10, 14, 17, 20, 22, and 26, 1917. Commercial quantities were taken in 1917 at 17 to 

 20 fathoms the first week of September and in 8 to 10 fathoms on September 24. 

 The inshore movement apparently had already begun on the 24th. 



BKEEDING HABITS 



The inshore movement in fall is for the purpose of spawning. While there are 

 no definite dates available as to when the eggs are deposited, the fishermen say that 

 the run is heaviest during the last two weeks of November, which may indicate that 

 this is the spawning period. The spawning season certainly falls in November, as 

 males taken during the first half of November, 1917, at Kagawong, Gore Bay, Wiarton 

 and Alpena show pearls. They spawn at depths of 4 to 8 fathoms on honeycomb 

 rock and gravel, according to the fishermen. It is interesting to note that the herring 

 spawns at about the same time and at about the same depth; in fact, both fish may be 

 caught in the same nets. The herring are said to spawn on sand and gravel, while 

 the pilot spawns on gravel and honeycomb rock. This leaves gravel as spawning 

 ground common to both. It may be found that the character of the gravel bottom 

 selected by the two species is different and that actually they do not spawn on the 

 same grounds at the same time. 



FOOD 



An examination of about 50 stomachs collected during October and November, 

 1917, at Alpena, Mich., and Kagawong, Ontario, shows the main items of food to be 

 Gastropoda, larval and pupal Trichoptera, and larval Ephemeridse. Adult insects, 

 larval Chironomidse, Asellus, Cambarus, Bryozoa, plant remains, and sand are 

 included among the articles occasionally ingested. 



The pilot is said to eat the spawn of other fish, and probably there is truth in the 

 charge. In fact, almost any fish will eat spawn if it gets a chance, and a fish that 

 feeds habitually on the bottom might be expected to prey heavily on spawn. At 

 least, the fish will eat spawn readily if it is offered them. During the last of October, 

 1919, pilot were common in 10 feet of water about the docks on the Greater Duck 

 Island. Hooks baited with trout spawn were grabbed instantly. It may be noted 

 in passing that as a game fish the pilot is not to be despised. On one occasion I had 

 an opportunity to determine whether the pilot sought the spawning grounds of other 

 fish. A box (2,250 feet) of 2%-inch nets was set on October 30, 1917, on the spawning 



