Chemical composition, fatty acids profile and cholesterol content of commercialized marine fishes captured in Northeastern Atlantic

Information available on the chemical composition and nutritional value of commercialized marine fish is very limited. The aim of this study was to investigate major nutrients of raw fish muscle and liver. Protein, moisture ash and lipid content were estimated for 14 commercialized species captured in Northeastern Atlantic. Proximate compositions were found to be varied among the studied species. Cluster analysis revealed two major groups based on proximate composition. Pontinus kuhlii and Trachurus picturatus formed one group, while the second group was formed by ten other species. Protein content was high in all species, varying between 18.51% in Phycis phycis and 32.69 % in Diplodus sargus. Fat content, on the other hand, was low and fish could be considered lean (lipid content <4%). Muscle fatty acid compositions consisted of 26.2-35.8% saturated fatty acids (SFA), 10.5-37.6% monounsaturated fatty acids (MUFA) and 28.7-57.5% polyunsaturated fatty acids (PUFA). Fish livers presented lower amounts of PUFA’s than muscles, mainly due to a reduction of the docosahexaenoic acid (DHA) content. Cholesterol content in liver revealed significant differences, ranging from 0.05 ±0.01 mg/g in Scorpaena scrofa to 7.58 ±0.19 mg/g in Aphanopus carbo. In fish muscle, cholesterol was low and was not correlated with lipids, fatty acids or PUFA content of the muscle.info:eu-repo/semantics/publishedVersio

Inclusion of low levels of blood and feathermeal in practical diets for gilthead seabream (Sparus aurata)

Rendered animal protein ingredients, such as feather meal and blood meal, are promising animal protein sources for the replacement of fish meal often proved to combine synergistically. Three practical diets containing similar amounts of PD/ED (22.0 mg/kJ) but differing in the amount of digestible protein were tested in sea bream juveniles of initial body weight 41.81±1.12 g. FBCM diet (40%PD) and FBM diet (42%PD) contained similar percentages of blood and feather meal (10% and 5%, respectively) but differed in the proportion of soybean / rapeseed meal. Although growth performance and feed utilization were very similar in all treatments, chemical composition showed that blood and feather meal supplementation increased significantly whole-body lipid content compared with fishmeal diet (P205A). Liver lipid content was significantly lower in fish fed FBCM diet. Whole-body fatty acids composition was similar between treatments, ranging between 242.57±14.17 mg g-1 in FBM diet and 274.62±23.95 mg g-1 for FBCM diet. Palmitic acid, oleic acid, linoleic acid; EPA and DHA were the most abundant fatty acids in both polar and neutral lipid fractions of the fish. Economical evaluation indicated that the incorporation of blood and feather meal as a substitute of fish meal decreased feed costs leading to a better economic conversion ratio.info:eu-repo/semantics/publishedVersio

A comparative analysis of lipid content and fatty acid composition in muscle, liver and gonads of Seriola fasciata Bloch 1793 based on gender and maturation stage

The fat content and fatty acid profile of commercially important Seriola fasciata (Lesser amberjack) was determined in samples of muscle, liver and gonads of both genders at pre-spawning and spawning stage. Results indicated that edible muscle of pre-spawning fish had high fat content(>8%), lowering to medium fat (4–8%) content during spawning stage. Livers and gonads presented more constant and relatively high lipid contents. Saturated fatty acids constituted the majority of the fatty acids, followed by monounsaturated fatty acids, with palmitic acid and oleic acid as the major fatty acid in all tissues. EPA and DHA content increased in spawning females and highest amounts were observed in the ovaries (222 and 1440 mg/100 g respectively). Livers presented lowest PUFAs content regardless of maturity stage and Sn 6/Sn 3 ratio was influenced by gender in this organ. Sn 3/Sn 6 was gender related during pre-spawning stage, increasing in spawning maturation stage. Results highlight variations in the nutritional value of the different tissues according to maturity stage and gender, emphasizing the need for consumer awareness of these changes.info:eu-repo/semantics/publishedVersio

Quality parameters of wild white trevally (Pseudocaranx dentex) natural spawn kept in captivity

The white trevally (Pseudocaranx dentex Bloch & Schneider, 1801) is a widely distributed carangid, commercially exploited in both the Pacific and eastern Atlantic. Most published works refer to the use of hormonal induction with gonadotropin-releasing hormone for egg supply with generally low fecundities and of poor quality. This study aimed to contribute for a better knowledge on the husbandry conditions that allow for natural spawning of white trevally in captivity. Wild white trevallies were kept in captivity for four years until natural spawning occurred. Nine breeders were kept in a 10m3 concrete tank at a density of 5 Kg/m3 , under natural photoperiod and natural water temperature fluctuations. Spawning started when water temperature reached 19 °C and lasted for two months. Viability rates varied between 35 and 79% and the average number of spawned eggs per female was of 280 × 103 . Egg total lipids (16%DW) and fatty acid profile (expressed as a % total detected) remained constant throughout the spawning season and were not correlated with any egg viability parameters. Neutral lipids, a major energy source in marine fish eggs and larvae, accounted for 50% of lipid classes, followed by glycolipids and phospholipids. Within lipid fractions, the neutral lipids presented high amounts of mono unsaturated fatty acids followed by equally high contents of polyunsaturated fatty acids. Docohexaenoic acid (DHA) was mainly found in the phospholipids fraction, though it was present in high amounts in all lipid classes. However, no significant correlations were observed between the DHA content and the egg viability parameters. The percentage of arachidonic acid (Ara) (< 0.1%) was low, possibly due to a deficiency of this fatty acid in the broodstock diet. Polyunsaturated fatty acids content, mostly represented by DHA and eicosapentaenoic acid (EPA), was positively correlated with hatching rate. Correlations observed between chemical composition of the eggs and viability parameters highlight the fact that egg quality is deeply influenced not only by environmental factors but also by broodstock management techniquesinfo:eu-repo/semantics/publishedVersio

Nannochloropsis gaditana grown outdoors in annular photobioreactors: operation strategies

Microalgae are a topic of intense research due to their potential applications in bio-based economy. However, sustainable commercial production is still overpriced due to high cultivation costs, harvesting and dewatering processes. In the present study, trials were conducted with the aim to improve daily operation strategies related to microalgae harvesting processes that did not compromise biomass productivity or the biochemical composition of the cultivated microalgae. Two experimental trials were performed in outdoor tubular annular photobioreactors to evaluate the effects of harvesting and medium dilution time (sunrise vs sunset) on Nannochloropsis gaditana biomass productivity, lipid and fatty acid content. Results showed that harvesting time had no significant effect on cell concentration and biomass productivity. Harvesting and medium dilution time did not affect lipid content. However, lipid content in samples collected at sunset was significantly higher than in samples collected at sunrise for both experimental treatments. The fatty acids profiles were mainly composed by polyunsaturated fatty acids, followed by mono-unsaturated fatty acids and saturated fatty acids. Regardless of medium dilution time, harvesting at sunset indicated that lipidic production (higher polyunsaturated fatty acids and lower saturated fatty acids) was favored without affecting the biomass productivity. The current study showed harvesting in the afternoon is a viable option for large production units that use semi-continuous strategy, without compromising biomass cell and lipid productivity.info:eu-repo/semantics/publishedVersio

Persistent genital arousal disorder: always look beyond the surface - a case report

Persistent genital arousal disorder is a rare condition characterized by unwanted intrusive symptoms of sexual arousal without specific context. Their possible aetiologies and treatments are multiple and mostly based on case reports. We aim to do a comprehensive review of persistent genital arousal disorder and describe a case of a postmenopausal woman who developed this disease and, during the follow-up, was diagnosed with advanced endometrial cancer, reminding physicians to keep in mind the possibility of multiple diagnosis in the same patient, including malignancy. Although there is no description of this association in the literature, the possible aetiologies of persistent genital arousal disorder are diverse, and we sought this rare case should be disclosed

Lipid and fatty acid composition of wild Almaco Jack Seriola rivoliana at two maturation stages

Almaco jack (Seriola rivoliana) is an emergent marine finfish that presents high market value. In order to study the feasibility of the exploitation of this marine resource for human consumption the evaluation of the nutritional characteristics of this species has attracted the attention of the scientific community. The lipid characteristics and fatty acid composition were evaluated in muscle, liver and gonad tissues of wild Almaco jack from Atlantic Ocean at two different maturation stages. According to results, the lipid content was found higher at pre-spawning stage (21.78 - 36.17%) and highest proportion being exhibited in the liver. Palmitic acid was predominant among the saturated fatty acids (35.42 - 47.80%) and oleic acid was detected as the main monounsaturated acid (25.26 - 36.55%). Higher amounts of ω3 polyunsaturated fatty acids (PUFAs) were identified in gonads of resting females, of which more than 84% was accounted by docosahexaenoic acid (12.62%). Muscle and liver of resting females presented the highest ω3/ω6 ratios. The Hypocholesterolemic/Hypercholesterolemic index was higher in gonads of both maturation stages (0.97 and 1.05). The results showed that wild Almaco jack at resting stage were a better source of oleic acid and ω3 PUFAs and that liver and gonads present good nutritional by-products.info:eu-repo/semantics/publishedVersio

Non-Indigenous Species on Artificial Coastal Environments: Experimental Comparison between Aquaculture Farms and Recreational Marinas

Globally, there is growing concern regarding the effects of the increasing anthropogenic pressures in marine communities. Artificial structures such as marinas and aquaculture facilities serve as invasion hotspots; hence, monitoring fouling communities on these structures can be valuable for detecting new invasions. In the current study, 24 settlement PVC plates were deployed for three months to compare the recruitment ability of these two artificial environments along the south coast of the offshore island of Madeira (NE Atlantic). The results showed higher variations in the species richness between regions (SW vs. SE) than between artificial habitats (sea-cages vs. marinas), although the community composition differed. Cnidaria and Bryozoa were the most representative groups in the aquaculture systems, while Bryozoa and Chordata were in the marinas. A sum of 18 NIS was recorded for the study, accounting for between 21.88% and 54.84% of the total number of species in the aquaculture facilities and marinas, respectively. The higher NIS percentage from the marinas was even more explicit in the SE coast, where Cradoscrupocellaria bertholletii, Parasmittina alba, and Botrylloides niger distinctly dominated fouling populations. The results suggest that at least some particular NIS previously reported in the studied marinas successfully colonized sea-cages. Future assessments need to address the potential role of aquaculture facilities as drivers for the secondary spread of NIS. Additionally, two new records are considered for Madeira: Eudendrium capillare and Ericthonius punctatus.Versión del edito

Marine vs freshwater microalgae exopolymers as biosolutions to microplastics pollution

Microalgae can excrete exopolymer substances (EPS) with a potential to form hetero-aggregates with microplastic particles. In this work, two freshwater (Microcystis panniformis and Scenedesmus sp.) and two marine (Tetraselmis sp. and Gloeocapsa sp.) EPS producing microalgae were exposed to different microplastics. In this study, the influence of the microplastic particles type, size and density in the production of EPS and hetero-aggregates potential was studied. Most microalgae contaminated with microplastics displayed a cell abundance decrease (of up to 42%) in the cultures. The results showed that the formed aggregates were composed of microalgae and EPS (homo-aggregates) or a combination of microalgae, EPS and microplastics (hetero-aggregates). The hetero-aggregation was dependent on the size and yield production of EPS, which was species specific. Microcystis panniformis and Scenedesmus sp. exhibited small EPS, with a higher propension to disaggregate, and consequently lower capabilities to aggregate microplastics. Tetraselmis sp. displayed a higher ability to aggregate both low and high-density microplastics, being partially limited by the size of the microplastics. Gloeocapsa sp. had an outstanding EPS production and presented excellent microplastic aggregation capabilities (adhered onto the surface and also incorporated into the EPS). The results highlight the potential of microalgae to produce EPS and flocculate microplastics, contributing to their vertical transport and consequent deposition. Thus, this work shows the potential of microalgae as biocompatible solutions to water microplastics treatment.info:eu-repo/semantics/publishedVersio

Microalgal-based biopolymer for nano- and microplastic removal: a possible biosolution for wastewater treatment

The increasing water pollution caused by the presence of nano- and microplastics has shown a need to pursue solutions to remediate this problem. In this work, an extracellular polymeric substance (EPS) producing freshwater Cyanothece sp. strain was exposed to nano- and microplastics. The bioflocculant capacity of the biopolymer produced was evaluated. The influence of different concentrations (1 and 10 mg L-1) of polystyrene nano- and microplastics in the extracellular carbohydrates and in the EPS production was studied. The presence of nano- and microplastics induced a negative effect on the microalgal growth (of up to 47%). The results show that the EPS produced by Cyanothece sp. exhibits high bioflocculant activity in low concentrations. Also, the EPS displayed very favourable characteristics for aggregation, as the aggregates were confirmed to consist of microalga, EPS and both the nano- and microplastics. These results highlight the potential of the microalgal-based biopolymers to replace hazardous synthetic flocculants used in wastewater treatment, while aggregating and flocculating nano- and microplastics, demonstrating to be a multi-purposed, compelling, biocompatible solution to nano- and microplastic pollution.info:eu-repo/semantics/publishedVersio