No abstract

Winter flounder Pseudopleuronectes americanus were collected at monthly intervals from December 2009 to May 2011, to describe the pattern and seasonality of oocyte development, including: (1) the group-synchronous transition from primary to secondary oocytes that initiates immediately after spawning, (2) the slow (months) development of vitellogenic oocytes followed by the rapid (weeks) maturation of oocytes, (3) the synchronous nature of mature oocytes ovulating, but the discrete releases of benthic eggs in batches, (4) the protracted (months) degradation of postovulatory follicles and (5) the occurrence of follicular atresia. Although fish were collected across only c. 2° latitudinal range, the spawning season was c. 1 month later in the Gulf of Maine (GOM) than on Georges Bank and in southern New England. This is probably due to lower temperatures in the GOM. These stock-specific data regarding the time course of oogenesis are of practical value. This information is discussed in relation to measuring and interpreting elements of reproductive potential such as maturation, skipped spawning and fecundity, the response of reproductive traits by this widely distributed species to changing climate and the response by this common, marine-estuarine species to urbanization, particularly environmental pollutants and dredging.

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