BUKBOT. 



535 



other fishes that have ;i distinct caudal fin. ()]\. iic- 

 coiint of the thick intcguniciit they are difficult to count. 

 The length of the middle rays varies between about 

 and 7 % (sonjetiines 8 or 9 %) of that of the body. 



The annl fin bcsiins nt a distiince from the tip of 

 the snout equal to about 4') — 48 % (sometimes 49 or 

 even nearly 50 ?») of the length of the body, and the 

 length of its base measures about 45 — 47 % (sometimes 

 42 or even 41 %) of that of the l)ody. Its rays, gener- 

 allv al)out 70" in numljer, are of the same structure 

 as those of the second dorsal fin, Init their height is 

 only ^/4 of that of the latter. 



The pectoral fin is large and rounded. It usually 

 measures ' . of the length of the head, but in one spe- 

 cimen we ha\e found it almost as long as the whole 

 licad. It is generally made up of 18 — "20 rays. Often, 

 however, according to Sun'devall, there are 22 rays on 

 one side or on botli, and sometimes, according to Kroyer, 

 ordy 17. At about the 7th or 8th ray we find 3 or 4 

 of the same length. The anterior and posterior rays 

 grow gradually shorter. The first is simple, and gener- 

 ally half the length of the fin. 



The insertion of the ventral fin lies entirely in front 

 of the base of the pectoral fin. The raAS are G or 7 

 in young Burbot, but in old ones quite as often 8. The 

 second ray is soft and thick, ' '^ longer than the others, 

 and somewhat separated from them. In young speci- 

 mens it is almost as long as the pectoral fin, in old 

 ones distinctly (as much as ^'^) shorter. The first ray 

 is as long as the third and free at the tip. 



The coloration, which is densely variegated with 

 yellow and black, intensifies in a high degree the re- 

 pulsive, Amphibian-like appearance of this fish. It is 

 extremely variable, however: sometimes plain, dark 

 blackish gray, sometimes lighter witli only small spots 

 of black on the upper part of the body. The relation- 

 ship to the Ling is expressed by the collection of the 

 black pigment into a more or less continuous band along 

 the margins of the vertical fins. In spite of all the 

 irregularity in the distribution and confluence of the 

 spots we can generally trace a longitudinal band on the 

 cheeks and snout. The inner (hind) surface of the pec- 

 toral fins is bluish. The belly and the ventral fins are 

 generally pale and wliitisli, Imt sometimes only slightly 



lighter tlian ihe sides of the body. Tlie fry seem al- 

 ways to be of a plain, dark colour. 



Of the internal organs we may give the following 

 particuhirs. The liver is rather large, reddish white, 

 set on the left side, and undivided. A rather small lobe 

 projects on the right side and covers the gall-bladder''. 

 The peritoneiini is \vliite. The stomadi, which foi-nis 

 an inimediate contiiutation of the a-sophagus, extends 

 along only slightly more than ' 3 of the abdominal ca- 

 vity, and is furnished internally with 7 large longi- 

 tudinal folds, whicli disappear when it is distended. 

 Only one side, the side from which the pyloric part 

 starts, is smooth and contains small, dense, digitate 

 glandules, hardly a millimetre in breadth. The pyloric 

 part originates on the under side of the stomach, in a 

 line witli tlie tip of tlie liver, not far from the bottom 

 of the stomacli. It is small and narrow, but thick- 

 walled and firm. It is continued in a forward direction 

 by the intestine, which at the very beginning has two 

 bunches, one on each side, of 20 — 24 appendages, ir- 

 regularly united at the base into a smaller luunber of 

 ducts. The intestine soon bends back to the anal region, 

 whence it returns forAvard, again to bend back to the 

 vent. It is of uniform thickness, only tlie last portion 

 (the rectum) being somewhat wider, closed by a valve 

 (like a ralntJa coll), and furnished internally with five 

 or six, not very distinct, longitudinal folds. The spleen 

 lies at the hind pai't of the middle coil of the intestine. 

 The ovaries are coalescent behind, with a common ori- 

 fice, which opens behind the vent. They are hung in 

 a distinct mesenterium or fold of the peritoneum. The 

 ripe eggs are flame-yellow and rather small, 0'8 — 1 mm. 

 in diameter, Imt exceedingl)- numerous, forming a mass 

 of considerable size. Hermaphrodites are not so very 

 rare; one specimen of this kind was described as early 

 as 1800 by Professor Pipping of Abo^ The air-bladder 

 is fairh- large and firm, lying close to the spinal column. 

 It is somewhat compressed at the middle, grows wider 

 anteriorly, and ends in front in two lobes, or with two 

 obtuse corners or short ramifications, which occupy the 

 anterior elongations of the abdominal cavity beside the 

 dorsal column and the occiput. The kidneys form a 

 fairly large, roundish, gray-brown reddish mass behind 

 the air-bladder and the vent. They have only small. 



" In one young specimen, however, we have connfed 89. 



* According to Beax (1. c), Dall found in male Burbot from Alaska two or even three, distinct gall-bladders, opening into a com- 

 mon gall-duct. 



<• Vet.-Akad. Handl. 1800, p. 33. tab. I. tig. 1. 



