A comparison of length-, weight-, and age-specific fecundity relationships for cunner in Cape Cod Bay

Understanding reproduction and recruitment is essential for the successful conservation of a species. An estimate of the fecundity of cunner Tautogolabrus adspersus is critical for assessing population dynamics and perturbation effects. In this study, we estimated length-, weight-, and actual age-specific fecundity relationships for cunner in Cape Cod Bay, Massachusetts. We used the gonadosomatic index to assist with selection of mature, prespawning-size fish for estimating fecundity. We then gravimetrically estimated fecundity for 205 fish 69–185 mm in total length that were collected in May and June 1994. Quadratic models on log10-transformed length and weight data each explained 71% of the variance in fecundity, and age data explained 57% of the variance. In a test of age-specific fecundity precision, three age-specific models (actual age, age back-calculated from the von Bertalanffy equation, and a calculated age estimate that was expanded to include additional data) produced consistent fecundity estimates. Finally, a comparison of length-, weight-, and age-specific fecundity relationships showed few differences among the models, suggesting that the more easily obtained length-specific fecundity relationship (log10 F = 24.954log10 L − 5.348log10 L2 − 24.421; R2 = 0.71) is appropriate for future cunner modeling studies