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The depletion and overexploitation of several fish stock demands for a valorisation of non-target and discarded species. Nonetheless, such species are often poorly studied, and information on their biological parameters must be gathered for effective population management. For 1 year, the reproductive strategy of the piper gurnard Trigla lyra and the red gurnard Chelidonichthys cuculus was studied by monthly samples obtained from commercial boats operating on western Portuguese coast. Both species showed a biased sex ratio towards females, especially for larger length classes. Length at first maturity could be estimated only for red gurnard (22.1 and 19.9 cm for females and males, respectively) because all piper gurnard individuals caught were mature. Piper gurnard showed determinate fecundity and a short spawning season, from November to February with a peak in January, whereas red gurnard showed indeterminate fecundity and a wide spawning season, from late December to May. The relative annual fecundity estimated for red gurnard (1893 ± 728 oocytes × g -1 eviscerated weight [EW]) was higher than the one estimated for piper gurnard (1018 ± 250 oocytes×g -1 EW). Although important information for understanding the species dynamics is presented in this study, additional information on other life-history parameters and of species landings is required., (© 2021 Fisheries Society of the British Isles.)

Abstract: The age, growth and reproductive biology of bluemouth, Helicolenus dactylopterus were studied in order to assess the use of these life history parameters as possible population discriminators in Portuguese waters. Fish were obtained from commercial landings in mainland Portugal (Peniche), Azores, and Madeira and supplementary samples were obtained from research surveys in the Portuguese continental slope. Significant differences in mean total-length and mean length-at-age were found between the three areas. The reproductive biology was analysed using the annual sexual cycle, three bionergetic indexes and the maturity ogives. Individuals presented a similar reproductive strategy in Portuguese waters with asynchrony of sexual cycles, similar female spawning season in the three areas and a sperm retention period in the ovaries of 1 to 6–7 months. The bionergetic indexes showed significant differences through the maturative stages and among areas. No significant differences were obtained when comparing the length at first maturity between mainland Portugal and Azores for both sexes. The results of this study will provide a comprehensive understanding of this species life history and presented useful evidence that can support the presence of different populations in the Portuguese waters. [Copyright &y& Elsevier]