Communications: Mortality of Coho Salmon Embryos Immersed in a Hypertonic Salt Solution for Varying Exposure Times

Abstract

Listen

Translate article

Abstract Eggs of coho salmon (Oncorhynchus kisutch) were incubated to the eyed stage and then mechanically shocked to allow for easy removal of dead or infertile eggs. Eighteen lots of approximately 7,190 live eggs were then placed in separate vertical incubator trays and immersed in a hypertonic solution of NaCl for 0–30 min. Mortality was low (1.4–2.4%) for eggs immersed for up to 10 min. For eggs immersed for 20 and 30 min, mortality increased to 9.5 and 81.4%, respectively. In normal hatchery operations where hypertonic solutions of NaCl are used to remove dead eggs by flotation, immersion times of less than 10 min appear to be safe.