Reproduction of the Blue Jack Mackerel, Trachurus picturatus, in Western Portugal: Microscopic gonad analysis reveals indeterminate fecundity and skipped spawning patterns

This study was partially supported by the European Maritime and Fisheries Fund MAR2020 project “VALOREJET: Valorização de espécies rejeitadas e de baixo valor comercial”, MAR- 01.03.01-FEAMP-0003 and by Fundação para a Ciência e Tecnologia through research contracts attributed to Vera Sequeira (CEECIND/02705/2017) and Ana Rita Vieira (CEECIND/01528/2017) and strategic project UIBD/04292/2020.Blue jack mackerel, Trachurus picturatus, is the fifth most landed fish species in mainland Portugal, but information on its reproductive biology is scarce. From September 2018 to August 2019, 626 specimens were collected from commercial vessels to clarify the reproductive strategy of the T. picturatus population off the west coast of Portugal. The proportion and length range of males and females were similar. Only three of the specimens collected were categorized as immature, indicating that the fish caught in the fishery are primarily mature. The spawning season lasted from late January until the end of March, with gonadosomatic indices being similar for males and females. Fecundity was indeterminate, and estimated batch fecundity ranged between 6,798 (at 25.4 cm TL) and 302,358 oocytes (at 33.8 cm TL). The low number of females showing direct evidence of imminent or recent spawning suggests a low number of spawning events. In addition, 12.7% of females were considered non-reproductive due to ovary abnormalities including parasitic infection by Kudoa species, atretic structures and skipped spawning events. This study highlights the importance of accounting for skipped spawning events and ovary abnormalities in the management of species fisheries.info:eu-repo/semantics/publishedVersio

Modelling Fish Growth with Imperfect Data: The Case of Trachurus picturatus

Growth modelling is essential to inform fisheries management but is often hampered by sampling biases and imperfect data. Additional methods such as interpolating data through back-calculation may be used to account for sampling bias but are often complex and time-consuming. Here, we present an approach to improve plausibility in growth estimates when small individuals are under-sampled, based on Bayesian fitting growth models using Markov Chain Monte Carlo (MCMC) with informative priors on growth parameters. Focusing on the blue jack mackerel, Trachurus picturatus, which is an important commercial fish in the southern northeast Atlantic, this Bayesian approach was evaluated in relation to standard growth model fitting methods, using both direct readings and back-calculation data. Matched growth parameter estimates were obtained with the von Bertalanffy growth function applied to back-calculated length at age and the Bayesian fitting, using MCMC to direct age readings, with both outperforming all other methods assessed. These results indicate that Bayesian inference may be a powerful addition in growth modelling using imperfect data and should be considered further in age and growth studies, provided relevant biological information can be gathered and included in the analyses.info:eu-repo/semantics/publishedVersio

Aumentar el conocimiento biológico para una mejor gestión de las especies de captura incidental: edad, crecimiento y mortalidad de garneo y arete (Teleostei: Triglidae)

Gurnards are a valuable by-catch of mixed demersal fisheries and are commercially important in European waters, but they are often discarded, reported under “mixed gurnards” and with incomplete biological information by species. In the present work, a total of 558 piper gurnard specimens of between 10.9 and 44.4 cm (1 to 11 years) and 425 red gurnard specimens of between 10.2 and 42.1 cm (0 to 9 years) from the northeast Atlantic (Portuguese) coast were used to study age and growth. The von Bertalanffy growth parameters for piper gurnard were estimated through the combination of whole-otolith readings and back-calculation (L∞=44.7 cm, k=0.16 yr–1 and t0=–2.781 yr). For red gurnard the same growth parameters were estimated using whole-otolith readings (L∞=40.2 cm, k=0.28 yr–1 and t0=–1.074 yr). The results indicate that the red gurnard reaches a smaller length, although it grows faster than the piper gurnard. Natural, instantaneous and fishing mortalities were estimated as well as the exploitation rate for both species. For the Portuguese coast, the red gurnard showed a higher fishing mortality and exploitation rate than the piper gurnard, raising concerns about its sustainable management.Los rubios son una captura incidental valiosa de las pesquerías demersales mixtas y comercialmente importantes en las aguas europeas, pero a menudo se descartan, se informan como “rubios mixtos” y con información biológica incompleta por especie. En el presente trabajo se han recogido un total de 558 ejemplares de ganeo, de entre 10,9 y 44,4 cm (1 a 11 años), y 425 individuos de arete, de entre 10,2 y 42,1 cm (0 a 9 años) procedentes del Atlántico nororiental (costa portuguesa) se utilizaron para estudiar la edad y el crecimiento. Los parámetros de crecimiento de von Bertalanffy para ganeo se estimaron mediante la combinación de lecturas de otolitos enteros y retrocálculo (L∞=44,7 cm, k=0,16 año–1 y t0=-2,781 años). Para el arete se estimaron los mismos parámetros de crecimiento usando lecturas de otolito entero (L∞=40.2 cm, k=0.28 año–1 y t0=–1.074 año). Los resultados indican que el arete alcanza una talla menor, aunque crece más rápido que el ganeo. Se estimó la mortalidad natural, instantánea y por pesca, así como la tasa de explotación para ambas especies. Para la costa portuguesa, el arete presentó una mortalidad por pesca y una tasa de explotación más altas que el ganeo, lo que generó preocupaciones sobre su gestión sostenible

The influence of change on sense of coherence on dental services use among adolescents: a two‑year prospective follow‑up study

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Preferential hyperacuity perimeter in the study of diabetic macular edema

Introdução – A diabetes é uma das maiores epidemias do último século. Mais de 250 milhões de pessoas, em todo o mundo, sofrem de diabetes. Das complicações derivadas da diabetes são as principais causas de cegueira, de insuficiência renal e de amputação de membros inferiores, derivando estes, predominantemente, da disfunção vascular. Quando surge perda de pericitos na parede vascular ocorrem uma série de alterações da microcirculação que levam ao aparecimento de microaneurismas e outras alterações vasculares que possibilitam a passagem de componentes sanguíneos para o tecido retiniano adjacente que, em situação de normalidade, não ocorreriam, sendo esta uma das causas do edema macular exsudativo diabético. A perimetria de hiperacuidade preferencial (PHP) é um teste psicofísico que pretende detetar metamorfopsias na Degenerescência Macular ligada à Idade (DMI). Uma vez que o edema macular diabético (EMD) se destaca como uma das principais causas de deficiência visual e baixa visão, pretende-se verificar a eficácia do PHP no estudo do edema macular diabético, respondendo à seguinte questão: “Qual a capacidade do perímetro de hiperacuidade preferencial em detetar metamorfopsias em pacientes com edema macular diabético?“ Metodologia – Estudo quantitativo, do tipo descritivo e correlacional. Selecionou-se uma amostra de 33 pacientes, onde se analisou um total de 60 olhos. Resultados – A sensibilidade do PHP na deteção de metamorfopsias associadas ao EMD na tomografia de coerência ótica (OCT) foi de 70,6%, a especificidade foi de 11,5% e a eficiência global do teste de 45%. Comparando os resultados encontrados no PHP e no OCT, constatou-se a existência de uma correlação inversa fraca (Phi = -0,215). Conclusões – Este novo método de diagnóstico revela-se sensível, contudo pouco específico e eficaz na deteção de metamorfopsias consequentes da existência de EMD. - ABSTRACT - Introduction – Preferential hyperacuity perimeter (PHP) is a new psychophysical test, which principle is based on the detection of metamorphopsia in age-related macular degeneration (AMD). It is intended to verify its effectiveness in the study of diabetic macular edema (DME). When there is loss of pericytes in the vascular wall occur a number of microcirculatory changes that lead to the appearance of microaneurysms and other vascular changes that allow the passage of blood components to the surrounding retinal tissue than in normal situation does not occur, this being one of the causes exudative diabetic macular edema. Methodology – It was performed a quantitative study, using descriptive and correlational analysis. A sample of 33 patients was selected, and 60 eyes were analyzed. Results – The sensitivity of PHP on the detection of metamorphopsia associated to EMD was 70.6%, the specificity was 11.5% and the global efficiency of the test was 45%. It was found a weak negative correlation (Phi= -0.215) between the PHP and optical coherence tomography (OCT). Conclusions – This new method of diagnosis was sensitive, but not very specific and effective on the detection of metamorphopsia, due to the DME

Adding value to bycatch fish species captured in the Portuguese coast—development of new food products

We live in a world of limited biological resources and ecosystems, which are essential to feed people. Consequently, diversifying target species and considering full exploitation are essential for fishery sustainability. The present study focuses on the valorization of three low commercial value fish species (blue jack mackerel, Trachurus picturatus; black seabream, Spondyliosoma cantharus; and piper gurnard, Trigla lyra) and of two unexploited species (comber, Serranus cabrilla and boarfish, Capros aper) through the development of marine-based food products with added value. A preliminary inquiry with 155 consumers from Região de Lisboa e Vale do Tejo (Center of Portugal) was conducted to assess fish consumption, the applicability of fish product innovation, and the importance of valorizing discarded fish. Five products (black seabream ceviche, smoked blue jack mackerel pâté, dehydrated piper gurnard, fried boarfish, and comber pastries) were developed and investigated for their sensory characteristics and consumer liking by hedonic tests to 90 consumers. The most important descriptors were identified for each product (texture, flavor, color, and appearance). Comber pastries had the highest purchase intention (88%), followed by black seabream ceviche (85%) and blue jack mackerel pâté (76%). Sensory evaluations showed a clear tendency of consumers to accept reformulated products, with the introduction of the low-value and unexploited species under study.info:eu-repo/semantics/publishedVersio

Adding Value to Bycatch Fish Species Captured in the Portuguese Coast—Development of New Food Products

We live in a world of limited biological resources and ecosystems, which are essential to feed people. Consequently, diversifying target species and considering full exploitation are essential for fishery sustainability. The present study focuses on the valorization of three low commercial value fish species (blue jack mackerel, Trachurus picturatus; black seabream, Spondyliosoma cantharus; and piper gurnard, Trigla lyra) and of two unexploited species (comber, Serranus cabrilla and boarfish, Capros aper) through the development of marine-based food products with added value. A preliminary inquiry with 155 consumers from Região de Lisboa e Vale do Tejo (Center of Portugal) was conducted to assess fish consumption, the applicability of fish product innovation, and the importance of valorizing discarded fish. Five products (black seabream ceviche, smoked blue jack mackerel pâté, dehydrated piper gurnard, fried boarfish, and comber pastries) were developed and investigated for their sensory characteristics and consumer liking by hedonic tests to 90 consumers. The most important descriptors were identified for each product (texture, flavor, color, and appearance). Comber pastries had the highest purchase intention (88%), followed by black seabream ceviche (85%) and blue jack mackerel pâté (76%). Sensory evaluations showed a clear tendency of consumers to accept reformulated products, with the introduction of the low-value and unexploited species under study.info:eu-repo/semantics/publishedVersio

Population wide testing pooling strategy for SARS-CoV-2 detection using saliva

SARS-CoV-2 pandemic has forced frequent testing of populations. It is necessary to identify the most cost-effective strategies for the detection of COVID-19 outbreaks. Nasopharyngeal samples have been used for SARS-CoV-2 detection but require a healthcare professional to collect the sample and cause discomfort and pain to the individual. Saliva has been suggested as an appropriate fluid for the diagnosis of COVID-19. We have investigated the possibility of using pools of saliva samples to detect SARS-CoV-2 in symptomatic and asymptomatic patients. Two hundred and seventy-nine saliva samples were analyzed through RT-PCR of Envelope, Nucleocapsid and Open Reading Frame 1ab genes. Reproducibility assays showed an almost perfect agreement as well as high sensitivity (96.6%), specificity (96.8%), positive predicted value (96.6%), and negative predicted value (96.8%). The average Cycle Threshold of the genes detected was 29.7. No significant differences (p > 0.05) were detected when comparing the cycle threshold average of two consecutive reactions on the same positive saliva samples. Saliva samples have a higher median viral load (32.6) than in nasopharyngeal samples (28.9), although no significant differences were detected (p > 0.05). Saliva-pool samples allowed effective SARS-CoV-2 screening, with a higher sensibility (96.9%) on 10-sample pools than in 20-sample pools (87.5%). Regardless of pools size specificity was high (99.9%) and an almost perfect agreement was observed. Our strategy was successfully applied in population wide testing of more than 2000 individuals, showing that it is possible to use pooled saliva as diagnostic fluid for SARS-CoV-2 infection.info:eu-repo/semantics/publishedVersio