Browsing by Author "Abreu, Paula"
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- ESCALA DE MATURAÇÃO MACROSCÓPICA E MICROSCÓPICA DO VERDINHO (Micromesistius poutassou)Publication . Gonçalves, Patrícia; Costa, Ana M.; Ferreira, Ana Luísa; Resende, Adelaide; Carmo Nunes Silva,; Abreu, Paula; Pechirra, Pedro; Instituto Português do Mar e da Atmosfera, I.P.Blue whiting (Micromesistius poutassou) is a mesopelagic teleost, of the gadidae family and widely distributed along the Atlantic North and Mediterranean. On the Portuguese coast, the main spawning season for this species occurs between January and March. At IPMA, the biological sampling of blue whiting is carried out regularly, in samples from discards collected onboard commercial vessels, fishing landings (Peniche, Matosinhos e Vila Real de St. António) and from scientific research surveys. Regarding the reproductive cycle, the identification of the maturity stages is made macroscopically during biological sampling. The maturity stage key currently in use at IPMA and applied to blue whiting is of the one suggested by Godinho et al. (2001), which was developed only based on macroscopic observations and descriptions, without microscopic validation. This study aims to microscopically describe the morphology of the gonads throughout the reproductive cycle for blue whiting, to validate and intercalibrate the macroscopic identifications based on histology and also to propose a new macroscopic maturity stage key taking into account the microscopic and macroscopic characteristics of the different stages from the sexual development cycle. Keywords: Blue whiting, Micromesistius poutassou, histology, macroscopic identification, microscopic maturity scale, macroscopic maturity scale.
- Validation of the macroscopic maturity stages for blue jack mackerel, Trachurus picturatus (Bowdich, 1825), according to histological examinationPublication . Feijó, Diana; Silva, Carmo Nunes; Correia, Georgina; Inácio, Mónica; Abreu, Paula; Costa, Ana Maria; Instituto Português do Mar e da AtmosferaThe assessment of fisheries resources requires the correct identification of fish maturity stages. The methodologies applied should be standardised and all uncertainty regarding macroscopic identification should be validated by microscopic observation. This work proposes a microscopic maturity scale for the blue jack mackerel (Trachurus picturatus, Bowdich, 1825), based on individuals collected by commercial bottom trawl in northern Portugal. After assigning the macroscopic maturity stage, the gonads were processed for histological observation. The slides were observed and the gonads were classified into 6 stages according to Walsh et al. (1990). The corresponding macroscopic and microscopic maturity stages were described. The correspondence to the new maturity scale presented at WKASMSF (ICES, 2018) is also presented, which is mandatory when reporting maturity data to ICES databases (since the 1st. January 2020).