EBPEODUOTION OF THE BUEBOT. 239 



separate aud loose upon the river or lake bottom. They are very small and numerous. According 

 to the calculation of Baron 0. G. Oederstrom, a medium-sized female contained 160,000 (by esti- 

 mate, 159,776) eggs. This result nearly coincides with that of a more recent estimate, viz, that 

 the average female contains 178,000 eggs. (Skand. Fiskar. vid., p. 41.) Some eggs are clear, some 

 yellow, all nearly colorless, and both kinds are capable of development. In some cases the eggs 

 commence to hatch in three weeks ; generally, however, an additional week is required. At the 

 end of the first day after the eggs have been deposited cleavage of the yolk commences. The eyes 

 appear in fifteen or sixteen days, and in about two days more small star-like spots may be observed 

 on the surface of the embryo. At that period, also, the beating of the heart can be plainly dis- 

 cerned, and I have alternately counted fifteen, thirty, and fifty pulsations in successive minutes. 

 The evolutions of the embryo are now more distinctly seen, and it will be noticed that the anterior 

 end of the embryo is the heavier. In many cases the eggs appear to have been prematurely 

 hatched, and assume the shape of a ring. These move but seldom, and always in a circle. A great 

 many die early ; others are developed. The fish with straight tails are very Lively, moving with 

 a tremor of the body, usually toward the surface of the water, whence they passively fall to the 

 bottom. When fully developed, the operation of swimming is accomplished by a quick movement 

 of the pectorals." 



Mode of captxjke. — The Burbot is taken on hooks, chiefly at night. It is also captured 

 largely in pounds and gill-nets. In Lake Winnipiseogee it is caught with the hook through 

 holes in the ice. At Fort Ouster, Montana, it takes the hook freely. In the Yukon Eiver it is 

 captured in fish-traps. 



Food and feeding habits.— The Burbot is carnivorous and voracious, having a craving and 

 wonderfully distensible stomach, which makes the fish an efflcient dredge in securing bottom fishes. 

 Through its medium was obtained the rare sculpin-like fish Triglopsis Thomsoni. The Burbot feeds 

 upon various small fishes and Crustacea, frequenting the bottom, and devouring more particularly 

 fishes with habits like its own. 



Forster gives the following notes in the " Philosophical Transactions," ^ which were furnished 

 him by Mr. Andrew Graham: " [The Marthy is] extremely voracious, eating fish, the pike, and the 

 tickomeg {Sahno), and other fish, carrion, putrefying deer, and even stones. Mr. Graham took a 

 stone weighing a pound from the stomach of one. ... It does not masticate its food." 



Pennant says that the Marthy "is so voracious as to feed even on the tyrant pikej will devour 

 dead deer or any carrion, and even swallow stones to fill its stomach." 



The Burbot seems to feed principally at night. Pennant states that it is caught with hooks 

 after nine o'clock at night. Charles Lanman states that "in the Saint John Eiver, Kew Bruns- 

 wick, some hundreds are taken annually by night-lines, dropped through the ice at the beginning 

 of winter. Many are thus taken near Fredericton, but the best fishing ground is on the sand- 

 bars, a little above the mouth of the Oromocto Kiver, where this fish resorts previous to spawn- 

 ing, which operation takes place in February or March. This fish is not unlike the eel in many of 

 its habits, concealing its food under stones, waiting and watching for its prey. It feeds principally 

 at night, and is, therefore, generally taken by night-lines." 



The specimens obtained by the National Museum from the Great Lakes always contained in 

 abundance the common species associated with itself in that region, such as Ferca americana, a 

 species of Lepomis, &c. 



According to Mr. Dall, the Burbot in the rivers of Alaska feed upon whitefish, lampreys, and 

 other species. 



'Vol. Ixiii. 



