Selection of Life Histories and its Adaptive Significance in a Snailfish Liparis tanakai from Sendai Bay

Abstract

Growth rate of snailfish is very high, eggs produced in late December-January becoming 400 mm in body length for male and 320 mm for female in the same period of the next year, and their life span is one year. Food habits shift from “number selection” depending mainly on crus-taceans to “size selection” relying in particular on sandeel in October when growth is the fastest. Spawning seems to be carried out in several batches of eggs 1.4-1.5 mm across and the fertility is estimated to be a hundred thousand and tens of thousands. Snailfish supposedly raises the probability for eggs to survive through caring for them by their fathers. Short life of snailfish along with parental care for eggs brings about a rise of the intrinsic rate of natural increase rm resulting in an elaborate regulation of population numbers. © 1983, The Japanese Society of Fisheries Science. All rights reserved.