A Life History Study of Atlantic Wolffish Resolves Bias and Imprecision in Length‐ and Age‐at‐Maturity Schedules by Recognizing Abortive Maturation

Abstract

Stock assessments of U.S. Atlantic Wolffish Anarhichas lupus are hampered by a landings moratorium and low catches in fishery-independent surveys. Working with the commercial fishing industry, we collected hundreds of fish to overcome a lack of regionally specific life history information. Based on ages from sectioned otoliths, Atlantic Wolffish are long lived (maximum observed age: males = 31 years, females = 29 years). A Gompertz growth model showed that Atlantic Wolffish exhibit dimorphic growth-with larger males across all ages on average. Preliminary estimates of total mortality ranged from 0.15 to 0.21 and were lower than an estimate measured at the beginning of the moratorium. Based on gonad histology, a cohort of vitellogenic oocytes emerged in mature females by April and developed group synchronously to ovulate primarily in October. Skip spawning, which accounts for nonannual spawning, was

Female age at maturity and fecundity in Atlantic Striped Bass

“…This developmental pattern in Striped Bass has been noted before in published field observations (see Chadwick 1965) but has not been accounted for in maturity studies. Similar descriptions of incomplete maturation during the known spawning period in other species have been referred to as "abortive maturation" (McBride et al 2022); however, we prefer the term "pubertal development," consistent with previous research on Striped Bass reproductive development. Abortive maturation implies a delay in first functional maturity in reaction to unfavorable internal or external factors, whereas pubertal development is the T A B L E 2 Histological description of developmental phases in the analysis.…”

“…Similar descriptions of incomplete maturation during the known spawning period in other species have been referred to as “abortive maturation” (McBride et al. 2022); however, we prefer the term “pubertal development,” consistent with previous research on Striped Bass reproductive development. Abortive maturation implies a delay in first functional maturity in reaction to unfavorable internal or external factors, whereas pubertal development is the physiological process occurring along the brain–pituitary–gonad axis that eventually leads to a competent reproductive system and first functional maturity (Okuzawa 2002).…”

“…This may represent a type of abortive maturation (McBride et al. 2022) or an additional step in pubertal development. Hassin et al.…”

“…Additionally, younger Striped Bass (as young as age 4) were observed to enter vitellogenesis but failed to spawn and were undergoing atresia. This may represent a type of abortive maturation (McBride et al 2022) or an additional step in pubertal development. Hassin et al (1999) observed that Striped Bass reaching sexual maturity for the first time had a lower GSI and lower accumulation of yolk than known-adult age-6 females.…”