Reproductive biology, growth, and natural mortality of Puget Sound rockfish, Sebastes emphaeus (Starks, 1911)

In spite of being one of the most common rockfish in the rocky nearshore region of the Strait of Georgia, relatively little is known about the early life history, ecology, recruitment, and reproductive biology of Puget Sound rockfish, Sebastes emphaeus. In rockfish, fecundity at 50% maturity ranges from 2,000 (S. dalli) to 417,000 (S. paucispinis) eggs per female. Parental care in this genus is essentially lecithotrophic, characterized by primitive, unspecialized viviparity at an evolutionary stage when eggs, embryos, and early larval stages are protected inside the female body rather than born live as fairly advanced young. Although most other northeastern Pacific Sebastes release their young between January and July, parturition occurs in August and September for Puget Sound rockfish. The goals of this study were to delineate the spawning season more closely and to determine the age and length at first maturity, the growth and mortality rates, and the length-fecundity relationship for Puget Sound rockfish.