Explore the vast range of titles available.

Fish age and growth data are crucial for understanding vital species’ traits and their populations. Boarfish is a pelagic species widely distributed in the Northeast Atlantic that is one of the most discarded non-commercial species on the Portuguese coast. Due to its potential valorisation as a new fishery in the Northeast Atlantic, boarfish has become object of interest in several published studies. However, since no age standard protocol has been implemented for boarfish, studies have used a variety of different otolith preparation techniques to estimate age, leading to contradicting and discrepant results. This research aims to consolidate biological insights into boarfish age and growth, lay the foundation for a standardized ageing protocol and serve as a benchmark study for the Portuguese west coast before commercial exploitation. Through the comparison of two otolith ageing methodologies, this study recommends using whole otoliths as the best method, revealing a maximum age of 15 years. The growth pattern estimated, indicated a biphasic growth pattern, with a faster initial growth rate that slows down at 2.4 years, the moment of change, when energy is allocated for sexual maturation. This finding was corroborated by a maturity ogive and analysis of fish size and otolith length relationship.

Most European fishing fleets will need to drastically reduce their unwanted catches to comply with new rules of the common fisheries policy. A more practical way to avoid increasing on-board sorting time and issues linked to storage capacity is to prevent unwanted catches in the first place. We assessed the selectivity properties of an experimental fishing gear that combined a 100 mm T90 cylinder with 130 meshes in the extension and a 100 mm T90 codend of 33 meshes (experimental gear) compared to a 100 mm diamond mesh extension and codend (control gear) during commercial trips using twin trawls. Analysis of the relative size composition of catches indicated a significantly higher escapement of small fish of several target species (e.g. Lepidorhombus whiffiagonis, Melanogrammus aeglefinus, Raja spp, and Lophius spp) and non-target species (e.g. Capros aper and Gurnards spp) from the T90 experimental trawl compared to the control trawl (n = 49 hauls), resulting in a significant reduction of unwanted catches of Gadidae, Triglidae, and Caproidae. In contrast, non-negligible commercial losses of small grade target gadoid species were observed. Mixed general linear models showed that the proportion of ray, haddock and anglerfish retained per length class decreased with increased tow duration. The T90 experimental gear will perform at a commercial level when targeting monkfish, megrim, rays and large haddock, however fishers are not likely to use this gear when targeting smaller-bodied species such as cephalopods, small haddock, whiting (Merlangius merlangus) and hake (Merluccius merluccius), because the gear is likely to allow large numbers to escape. Selectivity studies often focus on a short list of target species; however, catches of non-target species under quota can be problematic for some fisheries. For example, under the implementation of the Landing Obligation catches of boarfish could choke the French whitefish demersal fisheries in the Celtic sea, as France has no national quota for that species. The device tested constitutes an efficient solution to mitigate catches for such non-target schooling fish.

In this study we describe a new species Microcotyle tazeroutii n. sp. (Monogenea: Microcotylidae) found on the gills and operculum of the boarfish Capros aper (Caproidae) off the Algerian coast of the Western Mediterranean. Monogeneans were observed alive or recently dead on the operculum and gills using a dissecting microscope, measured and drawn for morphological study. Furthermore, a molecular analysis was conducted using a partial fragment of the mitochondrial cytochrome c oxidase subunit 1 (cox1) of two specimens of monogeneans and a tissue sample of the fish's gills in which the parasites were found to confirm the identity of fish. The new species Microcotyle tazeroutii n. sp., exhibits a combination of morphological features that differentiate it from all other known species within the genus, such as the shape and the size of body, the haptor length, the number and the size of clamps and testes, the number of spines of the genital atrium and the size of eggs. Additionally, a molecular analysis of the mitochondrial cytochrome c oxidase subunit 1 (cox1 gene) revealed significant interspecific differences between Microcotyle tazeroutii n. sp. and previously published sequences of other Microcotyle species. The morphological and molecular analyses revealed that Microcotyle tazeroutii n. sp. has unique characteristics that distinguish it from all previously identified species and confirmed the presence of Microcotyle within the Caproidae family for the first time.

Purpose In this study we describe a new species Microcotyle tazeroutiae n. sp. (Monogenea: Microcotylidae) found on the gills and operculum of the boarfish Capros aper (Caproidae) off the Algerian coast of the Western Mediterranean. Methods Monogeneans were observed alive or recently dead on the operculum and gills using a dissecting microscope, measured and drawn for morphological study. Furthermore, a molecular analysis was conducted using a partial fragment of the mitochondrial cytochrome c oxidase subunit 1 (cox1) of two specimens of monogeneans and a tissue sample of the fish’s gills in which the parasites were found to confirm the identity of fish. Results The new species Microcotyle tazeroutiae n. sp., exhibits a combination of morphological features that differentiate it from all other known species within the genus, such as the shape and the size of body, the haptor length, the number and the size of clamps and testes, the number of spines of the genital atrium and the size of eggs. Additionally, a molecular analysis of the mitochondrial cytochrome c oxidase subunit 1 (cox1 gene ) revealed significant interspecific differences between Microcotyle tazeroutiae n. sp. and previously published sequences of other Microcotyle species. Conclusion The morphological and molecular analyses revealed that Microcotyle tazeroutiae n. sp. has unique characteristics that distinguish it from all previously identified species and confirmed the presence of Microcotyle within the Caproidae family for the first time.

PurposeThe purpose of this study is to utilise market-oriented methodologies to determine key attributes driving consumers' preferences for novel sustainably sourced seafood concepts, derived from a species of wild-caught fish unfamiliar to consumers and to explore new product concepts for various consumer clusters.Design/methodology/approachThis study applied a mixed-method approach including five focus groups with 40 consumers and a single conjoint-based questionnaire administered to 300 seafood consumers in Ireland. The focus groups explored in-depth consumers' expectations, requirements and preferences and identified the key attributes that would influence acceptance of new seafood products. Full-profile conjoint analysis was used to model consumers' preferences for novel seafood product concepts that utilised a sustainably sourced species unfamiliar to the consumer.FindingsFocus groups revealed that the most important attributes were brand, price, format, packaging, supplementary information and accompaniment. The conjoint simulation identified three consumer clusters. Product concepts containing a sustainably sourced fish species were identified according to the preferences of each consumer cluster.Originality/valueThis research highlighted a sustainability angle in new product development and identified a competitive advantage and market potential for boarfish (Capros aper), which is an underutilised Irish fish species. It used a market-oriented approach to explore the development of novel sustainably sourced value-added seafood product concepts. The study results provide small and medium seafood companies with original and unique insights for developing novel sustainably sourced fish products that increase consumer acceptance.

This research has been carried out within the framework of the ECOFISH project: ecoinnovative strategies for sustainable fishing in the Gulf of Cadiz SPA. This initiative has been supported by the Biodiversity Foundation, the Ministry for Ecological Transition and Demographic Challenge, through the Pleamar Program, co-financed by the European Maritime and Fisheries Fund (EMFF) [grant number: 2019-016/PV/PLEAMAR18/PT; 2020-013/PV/PLEAMAR19/PT; 2020- 055/PV/PLEAMAR20/PT; 2021/PV/PLEAMAR20-21/PT; 2021-060/PV/PLEAMAR21/PT].

Target species diversification is essential for fisheries sustainability and fish market revitalization. Fish discards are a widely recognized problem resulting from fisheries worldwide, and are of major concern for all sector players, from administrations, to fishermen, and scientists. However, non‐target species are seldom studied, and information on nutritional profiles and seasonal changes in nutritional properties is generally lacking. This study assessed the seasonal nutritional composition of two unexploited (Serranus cabrilla, Capros aper) and three low commercial value fish species (Trachurus picturatus, Spondyliosoma cantharus, and Trigla lyra), captured on the Portuguese coast over 1 year. Significant seasonal variations were observed in the nutritional composition of all the species studied. Moisture and ash contents varied from 70% to 81% and from 5% to 13%, respectively. The maximum fat contents were 5% for C. aper and 4% for T. picturatus, allowing to classify all studied fishes as lean. The highest protein contents were recorded for C. aper (25%) and S. cantharus (20%). The unexploited and low commercial value fish species studied were shown to be good fat and protein sources, comparable to commonly consumed species, such as cod and salmon, having a great potential to become commonly consumed fish in Portugal. Non‐target species are seldom studied and information on nutritional profiles and seasonal changes in nutritional properties is generally lacking. This study assessed the seasonal nutritional composition of two unexploited (Serranus cabrilla, Capros aper) and three low‐commercial value fish species (Trachurus picturatus, Spondyliosoma cantharus and Trigla lyra), captured off the Portuguese coast over one year. The unexploited and low‐commercial value fish species studied were shown to be good fat and protein sources, having a great potential to become commonly consumed fish in Portugal.

Boarfish (Capros aper) is an underutilised pelagic fish species found in abundance in Irish waters. Research previously undertaken has shown a favourable effect of boarfish derived protein hydrolysate (BFH) consumption on glycaemic control in diabetic murine models. This study aims to investigate the effect of daily BFH consumption on glycated haemoglobin and body mass index (BMI) in overweight human participants. A randomised parallel placebo-controlled human intervention study was undertaken to investigate the effect of consuming BFH (3.5g/day) for 12 weeks. Participants (n = 40) that met the following inclusion criteria were recruited; aged between 18–65 years, non-smoker, not currently pregnant or lactating, BMI > 25.0 kg/m2, free from illness. Participants were randomly assigned to consume either BFH or cellulose capsules for 12 weeks. Measures taken at baseline and post-intervention (week 12) included fasting measures of: glycated haemoglobin, glucose, insulin, leptin, glucagon like peptide (GLP-1), adiponectin as well as lipid profile. Height and weight were also recorded at both timepoints. Analysis of covariance (ANCOVA) controlling for baseline values as well as other covariates (age & BMI), was used to compare differences between groups over time. Consumption of BFH (3.5g/day) for 12 weeks had no significant effect on glucose, insulin, leptin, glucagon like peptide (GLP-1), adiponectin, high density lipoprotein (HDL), total cholesterol, triglycerides, low density lipoprotein compared with control. No significant difference in glycated haemoglobin change over time (P = 0.123) was noted following consumption of placebo (2.5% increase) in comparison to those consuming the boarfish treatment (1.5% reduction). This study showed that 3.5 g of BFH per day did not elicit an effect on any of the markers of metabolic health. Previous studies investigating the effect of protein consumption on metabolic health have used higher concentrations than were utilized in this study, however using similar concentrations in this study was not plausible given the lack of organoleptic acceptability of the BFH. Addressing the organoleptic properties of BFH may enable future studies to increase the dose of BFH to a level that may be more efficacious than the current study.

Marine polar lipids (PLs) have exhibited promising cardioprotection. In this study, marine by-products such as salmon heads (SHs), their brain, eyes and main optic nerves (SBEON), and head-remnants after SBEON removal (RemSH), as well as herring fillets (HFs), herring heads (HHs) and minced boarfish (MB), were evaluated as potential sustainable sources of such bioactive PLs. The antithrombotic bioactivities of PLs derived from these marine by-products were assessed for the first time in human platelets against platelet-activating factor (PAF), thrombin, collagen, and adenosine diphosphate (ADP), while their fatty acid composition was evaluated by gas chromatography–mass spectrometry (GC-MS). PLs from all marine by-products tested possess strong antithrombotic activities against aggregation of human platelets induced by all platelet agonists tested. RemSH, SBEON, HHs, HFs, and MB exhibited strong anti-PAF effects, similar to those previously reported for salmon fillets. PLs from MB had the strongest anti-collagen effects and PLs from SHs and SBEON were the most active against thrombin and ADP. PLs from HHs had similar antithrombotic effects with those from HFs in all agonists. RemSH was less active in all agonists, suggesting that SBEON is the main source of bioactive PLs in SHs. All PLs were rich in omega-3 polyunsaturated fatty acids (ω3PUFA), such as docosahexaenoic acid (DHA) and eicosapentaenoic (EPA) acid, with favourable low values of the ω6/ω3 ratio. Salmon, herring, and boarfish by-products are rich sources of bioactive marine PLs with potent antithrombotic and cardioprotective properties.

Pelagic accumulations of fish are formed above the underwater mountains of the Whale Ridge in the evening and at night, but not observed during daylight hours. The study of such an accumulation above one of the mountains reveals its structure. The central part of the cluster consists of splendid alfonsino Beryx splendens, silver scabbardfish Lepidopus caudatus and oilfish Ruvettus pretiosus tend to keep on the periphery of the splendid alfonsino accumulation . Previously, it was found that food of splendid alfonsino, silver scabbardfish, rosefish Helicolenus mouchezi, Richardson’s boarfish Pentaceros richardsoni, and Cape bonnetmouth Emmelichthys nitidus consisted of organisms forming sound-scattering layers (SSL) above the underwater mountains. The composition of food and the daily dynamics of feeding of the listed commercial fish species indicate that they use two feeding tactics. In the first case, rosefish, Richardson’s boarfish, and Cape bonnetmouth forage for most of their food during the day at the bottom, when the SSL-forming organisms descend to the top of the underwater mountain during the diel migration. In the second case, splendid alfonsino, silver scabbardfish, and oilfish as part of a structured pelagic aggregation feed at night on the organisms rising into the upper layers of the water and forming sound-scattering layers. This tactic expands the possibilities for feeding fish that form pelagic aggregations in the dark hours of the day and allows the use of organisms both brought by the current to the mountain top and those that descended here earlier during the diel migration and then stayed until the beginning of the evening.