GREAT LAKES COREGONIDS 



421 



miles N. by W. % W.in30 to 40 fathoms (records 10 and 11); out of Grand Haven, 

 Mich., on March 20, 1919, 12 miles west in 50 to 55 fathoms (record 12); out of 

 Ludington, Mich., on August 30, 1920, 17 miles W. Y 2 S. in 60 to 70 fathoms (record. 

 13); out of Frankfort, Mich., on October 4, 1920, 9 miles north of Point Betsie in 

 60 to 70 fathoms (record 15); out of Northport, Mich., on June 22, 1920, and on July 

 31, 1923, 5 miles northwest of Cathead Light in 40 to 60 fathoms (records 16 and 17); 

 out of Charlevoix, Mich., on June 30, 1920, 3 miles northwest in 40 to 65 fathoms 

 and on August 11, 1923, 3 miles NW. Y 2 W. in 35 to 60 fathoms (records 18 and 19); 

 and out of Manistique, Mich., on August 12, 1920, 15 miles SE. by S. y 2 S. in 60 to 

 70 fathoms (record 20). All but the lifts out of Michigan City (records 10 and 11), 

 it will be noted, were made, at least in part, from depths of 50 fathoms or more. 

 In only one lift made at more than 50 fathoms were no blackfins observed, namely, 

 out of Sheboygan, Wis., on October 1, 1920. It was absent in about 12 other lifts 

 examined from nets set in less than 50 fathoms, the number not including those 

 lifts made out of Milwaukee, Wis., and Michigan City, Ind., on the spawning grounds 

 of zenitMcus and hoyi. 



My observations thus show that few blackfins were taken in the lifts examined 

 during 1920 and that these were, for the most part, from nets lifted from depths of 

 50 fathoms or more. The early writers (Hoy, 1870; Milner, 1872) also had observed, 

 or derived an opinion, that the blackfin was a fish of the deeper waters. If we turn 

 to the testimony of the fishermen, we find that the species was formerly abundant 

 in several localities, always at great depths. William Lahmann, a retired fisherman 

 of Milwaukee, says that they were formerly abundant 40 miles ESE. of Milwaukee, 

 Wis. (off Racine), in 80 to 90 fathoms, where they were caught while spawning in 

 December and January (record 7). Cornelius Tamms, likewise of Milwaukee, 

 states that he fished for blackfins with 33^-inch nets on these grounds from April 

 to June (record 8). Charles Hyttel, sr., of Racine, who furnished the type 

 specimen to Doctor Hoy, says that formerly he fished blackfins in 33^-inch nets off 

 the city at depths of 60 fathoms and more. They spawned there, he says, in January 

 (record 9). Peter and Hans P. Petersen, of Manistee, Mich, formerly fished black- 

 fins 5 to 8 miles west of Manistee in 43^-inch nets at depths of 40 to 80 fathoms in 

 December and January when the fish were spawning (record 14). Mr. Lahmann 

 and the Petersens give 1905 as the year of a marked decline in the abundance of the 

 species. Mr. HyttePs tug records show occasional fair lifts in 1907, especially in 

 January, but the records for succeeding years, including 1911, indicate takes of few 

 blackfins. 



BREEDING HABITS 



Nothing is known from personal observation of the time or place of spawning. 

 None of the specimens collected as late as October 4, 1920 (record 15), showed ripe 

 eggs, and those taken as early as March 20, 1919, were spent. Thus the spawning 

 season is some time between October and March. Observations of fishermen from 

 several ports fix the time and indicate the location of at least two spawning grounds. 

 Mr. Lahmann, of Milwaukee, and Mr. Hyttel, sr., of R acine, both have claimed to 

 have taken the fish on their spawning grounds, 40 miles ESE. of Milwaukee, in 60 to 

 90 fathoms during late December and early January. The Petersens say that they 



