The Biology and Taxonomy of the Burbot, Lota Lota Leptura, in Interior Alaska

Introduction -- Study area -- Materials and methods of collection -- Taxonomic status -- Age and growth -- Length and weight relationship -- Reproduction -- Food habits -- Acknowledgements -- Literature citedBased upon the high peduncle ratio, the pattern of its geographic variation, and the high vertebral and pyloric caecal numbers, the burbot in Alaska is considered subspecifically different from the southeastern North American burbot. The sub-specific name Lota lota leptura Hubbs and Schultz is accepted. A regression equation is given for back-calculating the previous lengths of the burbot at each age from the diameter of the corresponding ring of the otolith. Burbot grow slower but larger and live longer in Alaska than in many other areas. Specimens as long as 99.5 cm and as old as 24 years of age were caught. Most of the burbot in interior Alaska probably die before age 15. Male burbot have a shorter life span and grow more slowly in their later age than do females. The length and weight relationship changes seasonally and is related to the liver and gonad weights. The growths of liver and gonad are interrelated. Growth of the burbot in weight is also discussed. The reproductive habits of burbot are reviewed. In interior Alaska, the burbot mature at age 6 or 7 when the fish reach a length of 40 to 50 cm. Spawning takes place around February. A 1,230 g burbot produces abut 738,500 eggs. Summer food habits of burbot, and a point allotment method used in stomach analysis are described. The burbot eat mostly young burbot and sculpins. Young burbot eat mostly invertebrates, mainly Plecoptera. Young burbot seem to feed more intensively than do the adults