Frostfish (Atlantic Tomcod) Fall Migrations, Winter Spawning, and Fecundity.

Avery, Trevor¹, Hunter Hogan*¹, Zhe Yang¹, Lachlan Riehl², Darren Porter³, Erica Porter³, ¹Biology Department, Acadia University, Wolfville, NS, Canada, ²The Confederacy of Mainland Mi’kmaq, ³Minas Institute of Natural and Academic Sciences

Atlantic Tomcod Microgadus tomcod is known as frostfish in Mi’kmaw because of its fall upstream migration and winter spawning. Tomcod were sampled over five years in three river systems to characterize spawning run timing, gonadal maturation, and fecundity. Run timing begins in early October for a late December to early January spawning event. Gonadal development, measured by gonadosomatic index, varies slightly between males and females. Egg size analysis shows eggs ripen only shortly before spawning. Fecundity was related to total length and increases almost linearly.