Double or Nothing: Within Population Deviations in Reproductive Strategy in Chilipepper Rockfish (Sebastes goodei)

The paradigm of an annual reproductive cycle is being challenged in many fish species, with a rapid increase in recent years in the number of species for which “skipped spawning” has been documented.  Skipped spawning in females, commonly documented through mass atresia of developing oocytes, appears to be a relatively common phenomenon in deep, continental slope-dwelling rockfish species (Sebastes spp.) and occurs most frequently in adolescent fish.  An alternate, less understood phenomenon is the case of multiple brooding in rockfish, whereby an individual female produces more than the typical single batch of larvae in the course of a reproductive season.  Chilipepper rockfish (S. goodei), a continental-shelf dwelling species, exhibit both of these anomalies; however, the extent to which they are prevalent in the population and the underlying drivers are unknown.   Visual examination of fresh ovarian tissue allows detection of the presence of vitellogenic or late-stage atretic oocytes, but discernment of the earliest stages of oocyte development and atresia are difficult without histological examination.  These phenomena, and their potential influence on population dynamics and fisheries management, will be discussed.