Determining the indeterminate: Evolving concepts and methods on the assessment of the fecundity pattern of fishes

Despite its importance in applied fish reproductive biology the fecundity pattern (determinate vs. indeterminate) is still an open question for many fish stocks, often hindering the selection of the appropriate egg production method for the estimation of stock spawning biomass. As a rule of thumb it is considered that cold-water, capital breeders with short spawning periods are determinate spawners while warm-water, income breeders with extended spawning periods are indeterminate spawners. However, the exact biological and/or ecological mechanisms that lead to the one, the other or intermediate patterns are still uncertain. The present review describes the evolving concepts on fish fecundity patterns and overviews the important theoretical and methodological advances on the assessment of fish fecundity. This information is subsequently used to provide refined lines of evidence on the correct designation of the fecundity pattern of fish stocks. Finally, this review attempts to shed light on the possible links between the fecundity pattern and the specific environmental conditions encompassed by fish stocks and suggest future perspectives and conceptual models that could be developed in order to better explain and predict the fecundity pattern in fishes.