Procedures to Estimate Fecundity of Wild Collected Marine Fish in Relation to Fish Reproductive Strategy

Abstract

Appraisal of reproductive strategy and fecundity is necessary to evaluate the reproductive potential of individual fish species. To estimate reproductive potential, one needs to consider a variety of attributes including onset of maturity, fecundity, atresia, duration of reproductive season, daily spawning behaviour and spawning fraction. In this contribution, we review several methods currently used to estimate fecundity of marine fishes collected in the field in relation to their reproductive strategy. The advantages and disadvantages of each method are provided. Requirements are given to appropriately sample gonadal tissue that will enable researchers to establish incidence of sexual maturity and estimate fecundity.

Reproductive biology of mangrove jack (Lutjanus argentimacuiatus) in northeastern Queensland, Australia

“…No attempt was made to estimate annual fecundity for this species because of the lack of available information, particularly on spawning frequency. The large size of mature fish and the unavailability of suitable aquarium facilities meant that it was impractical to estimate spawning frequency by following batch production sequences of individual fish in tank experiments as has been described by some authors (e.g., Murua et al 2003). Similarly, another commonly used technique, the postovulatory follicle method (Hunter & Macewicz 1985), could not be used because the relatively low abundance of this species made it impossible to obtain sufficient gonad samples from wild spawning fish.…”

Age composition, growth, and reproductive biology of yellow catfish (Peltobagrus fulvidraco, Bagridae) in Ce Lake of Hubei Province, Central China

“…The fecundity of each fish was then estimated as the weighted mean density of the three subsamples multiplied up to determine the total ovary mass. If the coefficient of variation was higher than 5%, then additional samples were counted (Murua et al 2003). The absolute fecundity of yellow catfish was recorded as the number of mature eggs in the ovaries of ripe samples.…”

“…Fifty-nine ovaries at stage IV and V were chosen from fish collected from April to August of 2005, when GSI values were highest, to estimate absolute fecundity and relative fecundity. The oocyte packing density in the ovary was investigated to ensure that the subsamples were representative of the entire ovary (Murua et al 2003). Natural logarithm transfer of oocyte density was used to comply with the assumption of homoscedasticity.…”

“…Based on recent assessment of this species, the natural stock is probably at a reduced reproductive capacity and at risk of being harvested unsustainably (Liu 1997;Luo et al 2005). Knowledge of the reproductive biology and the estimation of fecundity and egg production are fundamental in the study of the population dynamics of fish species (Hunter et al 1992;Murua et al 2003), as they are basal to quantify reproductive capacity at both individual and population levels of a fish species. Manipulation of fish's reproductive system under artificial conditions also requires an understanding of natural spawning patterns and other influential factors based on information of the species' reproductive biological characters such as size-at-sexual maturity, the duration and periodicity of spawning.…”

Changes in size at maturity of European hake Atlantic populations in relation with stock structure and environmental regimes

“…Those ogives are usually calculated from a macroscopic evaluation of the gonad maturity. However, macroscopic analysis may overestimate the proportion of mature females (Murua et al, 2003;Vitale et al, 2006).. Moreover, in most scientific assessments of European marine fish stocks, SSB is calculated using a fixed maturity ogive, ignoring the inter-annual variability in this parameter.…”