Reproductive Biology of Southwest Scotian Shelf Haddock (Melanogrammus aeglefinus)

Abstract

Information on the reproductive biology of Southwest Scotian Shelf haddock (Melanogrammus aeglefinus) (NAFO Division 4X) is presented including geographic distribution by maturation stage, timing of maturation, seasonal changes in gonad weight, spawning distribution in relation to environmental factors, and fecundity at length, weight, and age. Haddock were found to spawn on Browns, Baccaro, LaHave, and Roseway Banks over sand/gravel substrates. Spawning fish were found in a narrower and colder temperature range than were fish of other maturity stages. Spawning fish were found from April to August with peak activity occurring from April to June. Testes peaked in weight in February and March when they accounted for 1–2.2% of body weight while ovaries reached their maximum size (3.1–12.5% of body weight) from late March to mid-May. The length at 50% maturity varied over the period 1970–85 and these changes were correlated with changes in population biomass. There were no significant differences in fecundity/length relationships with area or year (1983–86) but fecundity for a given size decreased over the spawning season.