| Summary: | The Life-History of the Spiny Dogfish (Squalus acanthias) and the Vitamin A Values of Dogfish Liver Oil Abstract -- Introduction -- Materials and methods -- General life-history of Squalus acanthias. Sizes of dogfish caught and onset of sexual maturity -- Sex ratio -- Growth and reproduction. Embryos in uteri -- Growth curve of young -- Growth. Growth of male and female embryos in uteri -- Growth of male and female dogfish after birth -- Calculations of growth of dogfish from European data -- Application of European data to growth of Squalus acanthias on the North American coast -- Other criteria of dogfish growth -- Weight -- Reproduction. Length of female dogfish versus total number of large yellow eggs in both ovaries -- Length of female dogfish versus total number of tiny embryos in both uteri -- Length of female dogfish versus total number of large embryos in both uteri. Discussion -- Relation of length of parent dogfish to size of large embryos, of tiny embryos, of ovarian eggs and of uterine eggs -- Number of large yellow eggs in each ovary and the number of young in each uterus -- Development of ovarian eggs -- The egg-case and its contents -- Relations between length of adult, embryo size and yolk-sac size -- Sources of food, water, etc., in Squalus embryos -- The food of the dogfish -- Relation of sexual maturity of male dogfish to length of claspers -- Relation of sexual maturity of female dogfish to the length and to the width of the uterus -- Dogfish appearances and migrations. Earliest date of capture of dogfish in Newfoundland and Labrador, 1942 -- Months during which dogfish are present -- Months during which dogfish are usually plentiful -- Additional information on movements of dogfish -- Indications of movements of mature and of immature male and female dogfish as shown by our captures off St. John's -- Tagging -- Minimizing the dogfish pest -- Quantities of dogfish present and their uses. Abundance -- Dogfish as human food -- Other uses of dogfish flesh -- Dogfish livers and liver oil. ...
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