The devil firefish Pterois miles (Bennett 1828) is recognized as one of the 100 worst invasive alien species (IAS) in the Mediterranean Sea with significant socioeconomic and ecological implications. A total of 363 individuals were collected between April 2021 and March 2022 from the Levantine Sea (the Eastern Mediterranean), aiming to assess the current progression of the population. The male to female ratio (1:1.03) did not significantly depart from 1:1, with length–weight relationships exhibiting positive allometric growth. Five age groups were identified, with the third and fourth age groups being the predominant (74% of the population). The highest reproductive intensity was observed during summer followed by autumn. The onset of sexual maturity (L50) for the total population was estimated at 22.44 cm in total length (2.1 years). The asymptotic length was estimated at 45.35 cm for the total population, with males growing larger than females. Longevity was estimated at 14.4 years for the total population. The inflection point was estimated at 4.31 years for the total population. Length with a 50% probability of capture (LC50) was estimated at 23.03 cm, with the respective age (t50) of 2.2 years. The exploitation rate (E = 0.48) indicated that the population is underexploited. The optimum (Fopt) and target (Flim) fishing mortality were higher in comparison with the present fishing mortality (F = 0.41), indicating a potential for commercial exploitation of the species.

Low-cost plant-based sources used in aquaculture diets are prone to the occurrence of animal feed contaminants, which may in certain conditions affect the quality and safety of aquafeeds. Mycotoxins, a toxic group of small organic molecules produced by fungi, comprise a frequently occurring plant-based feed contaminant in aquafeeds. Mycotoxin contamination can potentially cause significant mortality, reduced productivity, and higher disease susceptibility; thus, its timely detection is crucial to the aquaculture industry. The present review summarizes the methodological advances, developed mainly during the past decade, related to mycotoxin detection in aquafeed ingredients, namely analytical, chromatographic, and immunological methodologies, as well as the use of biosensors and spectroscopic methods which are becoming more prevalent. Rapid and accurate mycotoxin detection is and will continue to be crucial to the food industry, animal production, and the environment, resulting in further improvements and developments in mycotoxin detection techniques.

A fishery-independent survey with a commercial bottom otter trawl was conducted in the Pagasitikos Gulf, a semi-enclosed, trawl-restricted gulf in Greece. The study aimed to ecologically assess the fishery communities that are experiencing a decline in fishery landings. Twelve hauls of 30 min duration each were conducted in the eastern, western, and central parts of the gulf at depths between 62 and 97 m. In total, 57 species were captured, with the highest species number recorded in the west (35 species), followed by the center (32 species) and east (29 species). The highest numerical abundance was recorded at the center, followed by the east and west, with an opposing trend exhibited for biomass; however, GLM detected no significant spatial differences (in area or depth) or interaction. Ecological indices exhibited significantly lower values in the west–east area comparison. Linear Discriminant Analysis, mMDS, and hierarchical clustering indicated the presence of two main groups (east and west), with PERMANOVA showing a significant difference in the demersal communities among the identified groups. The results indicated moderately disturbed demersal communities and an increasing level of disturbance from east to west. Considering the economic value of Pagasitikos to the local fishing community, additional fishery management measures are deemed necessary to protect the fishery resources and mitigate the potential risks of overexploitation.

This study examined the modulatory effect of two commercial feed additives, Lumance® (0.2% and 0.5%) and Novigest® (0.4%), on the growth and microscopic structure of the intestine and liver of juvenile gilthead sea bream (Sparus aurata), when added to high (HFM-0) and low fish meal (LFM-0) diets. Lumance® was added only in the HFM-0 diet (HFM-0.2 and HFM-0.5), while a mixture of the two additives was used in the LFM-0 diet (LFM-0.6: 0.2% Lumance® + 0.4% Novigest® and LFM.0.9: 0.5% Lumance® + 0.4% Novigest®). Fish fed the HFM diets exhibited the highest overall growth, and significant differences were recorded in the specific growth rate (SGR), daily growth index (DGI), feed conversion ratio (FCR) and thermal growth coefficient (TGC), between the HFM and LFM dietary treatment groups. Supplementation of the additives had no effect on the growth performance in either of these groups. The analysis of the intestinal histomorphometric measurements showed signs of intestinal inflammation in the fish fed the LFM-0 diet. The addition of the two additives exhibited some modulatory effects, particularly increased intestinal villi length and lamina propria width in the mid-intestine. An increased number of intraepithelial cells and mucus production was also observed, as well as a decrease in hepatic vacuolation in the LFM-0.6 and LFM-0.9 groups, but not at a statistically significant level.

Insects are considered a sustainable alternative protein source in aquaculture diets. So far, most studies regarding the inclusion of inset meals in the diets of farmed fish focus on one insect species individually and they are examining the effect of different insect meal inclusion levels. This is a comparative study of the use of three different insect species in the diets of European sea bass. During the twelve-week experimental period, fish (average initial weight of 5.7 g) were fed with isonitrogenous and isoenergetic diets in which 30% of the fish meal was substituted with insect larvae meals from Tenebrio molitor (TM), Hermetia illucens (HI) or Musca domestica (MD) three times a day for seven days per week. Under the experimental conditions, growth performance was similar in fish fed either insect inclusion diets or the fish meal diet. The inclusion of TM resulted in a slight increase in feed conversion ratio. The inclusion of HI or MD did not significantly affect the whole-body composition and nutrient retention; however, inferior nutrient efficiencies were observed when fish meal was replaced with TM. The fatty acid content of the diets affected greatly the whole-body fatty acid composition. Fish fed on the rich in n-3 polyunsaturated fatty acids diets (FM and HI) had the highest content of n-3 fatty acids while fish in the TM and MD groups had the highest n-6 polyunsaturated fatty acid content due to the abundance of these fatty acids in the TM and MD diets. The whole-body amino acid profile was not affected by different insect diets or FM replacement. Amino acid retention varied between groups without showing any dietary effect. Plasma cholesterol levels were lowered in fish fed the TM and MD diets. Plasma triglycerides, phospholipids and lactate were not affected by the FM substitution, but differences occurred between the insect diets. Liver amino acid catabolizing enzymes activities (ALT, AST and GDH) were similar in all fish groups. Overall, this study shows the efficacy of insect meals as a fish meal substitute and that fish meal can be successfully replaced by Tenebrio molitor, Hermetia illucens and Musca domestica meals in 30% in the diets of European sea bass.

The determination of organic and inorganic pollutants in fish samples is a complex and demanding process, due to their high protein and fat content. Various novel sorbents including graphene, graphene oxide, molecular imprinted polymers, carbon nanotubes and metal-organic frameworks (MOFs) have been reported for the extraction and preconcentration of a wide range of contaminants from fish tissue. MOFs are crystalline porous materials that are composed of metal ions or clusters coordinated with organic linkers. Those materials exhibit extraordinary properties including high surface area, tunable pore size as well as good thermal and chemical stability. Therefore, metal-organic frameworks have been recently used in many fields of analytical chemistry including sample pretreatment, fabrication of stationary phases and chiral separations. Various MOFs, and especially their composites or hybrids, have been successfully utilized for the sample preparation of fish samples for the determination of organic (i.e., antibiotics, antimicrobial compounds, polycyclic aromatic hydrocarbons, etc.) and inorganic pollutants (i.e., mercury, palladium, cadmium, lead, etc.) as such or after functionalization with organic compounds.

White sea bream (Diplodus sargus) and brown meagre (Sciaena umbra) were caught from the wild in Aegean Sea (Greece), and studied for their proximate, fatty acid and amino acid composition to evaluate their nutritional value for human consumption and their potential as candidate fish species for Mediterranean aquaculture diversification. Both species exhibited very low muscle fat, ranging at 1%. White sea bream was found to have higher muscle eicosapentaenoic (EPA) and docohexaenoic (DHA) contents and total n-3 fatty acids than brown meagre. A superiority of white sea bream in aspects of thrombogenicity was indicated, showing higher atherogenic (0.679) and thrombogenic indices (0.377) comparing to the respective values for brown meagre (0.610 and 0.579). The two-studied species exhibited high-quality protein as food source, with white sea bream showing a higher essential to non-essential amino acid (EAA/NEAA) rate, 0.764 vs 0.704, respectively. The individual to total essential amino acids rates of lysine and leucine were the highest ones for both studied species, while no significant differences were observed among them.

Background: Danofloxacin is a synthetic antibacterial agent with broad spectrum antibacterial and antimycoplasmal activity which is widely used in aquaculture. Methods: A UPLC (Ultra Performance Liquid Chromatography) method was developed and validated for the determination of danofloxacin (Dano) and its major metabolite N-desmethyl danofloxacin (N-desmethyl Dano) in muscle plus skin tissue of European seabass (Dicentrarchus labrax) for the first time. For the separation an analytical column UPLC BEH C-18 2.1 x 5 mm (1.7 mu m) was used with an isocratic mobile phase consisting of MeOH-water acidified with formic acid (0.01%) (18: 82; v/v) and flow rate of 0.3 mL/min within 5.5 min. The detection was performed at 275 nm using a photodiode array detector for both compounds. Examined fluoroquinolones were isolated from seabass muscle and skin tissue by extraction with acidic ACN and further purification with the QuEChERS methodology. Results: Recovery rates from muscle and skin tissue ranged between 90.2 and 101.2% for both compounds. The detection limit of the method was estimated at 13.73 mu g/kg for Dano, 18.32 mu g/kg for N-desmethyl Dano, while the limits of quantification were 41.62 and 55.52 mu g/kg, respectively. The developed method was fully validated in terms of selectivity, linearity, accuracy, precision, stability and sensitivity according to the European Union Decision 2002/657/EC. Conclusion: The new developed and validated method can be readily applied to aqua cultured fish after dietary administration of danofloxacin.

A UPLC-QTOF-MS method for the simultaneous determination of 20 veterinary drug residues and metabolites (tetracyclines, quinolones, sulfonamides and diaminopyrimidines) in edible muscle plus skin tissue of European sea bass (Dicentrarchus Labrax) was developed. For the identification of analytes a positive electrospray ionization quadropole time-of flight mass spectrometer operating in MSE mode (UPLC-QTOF-MSE) was used. MSE mode provides high chromatographic resolution and accurate mass measurements in both MS and MS/MS modes simultaneously in a single run. Separation was achieved on a UPLC BEH C18 (50 mm X 2.1 mm, 1.7 mu m) column in a gradient elution program of 10 min. Examined antibiotics were isolated easily after a simple solid-liquid extraction procedure with acidic acetonitrile (0.1% v/v formic acid) and Na-2 EDTA 0.1 M. Recovery rates from muscle plus skin tissue ranged from 93.8% to 107.5% for all targeted compounds. The detection limits and the limits of quantification ranged from 2.22 to 15.00 mu g/kg, and from 6.67 to 45.46 mu g/kg, respectively. The developed method was validated in terms of selectivity, matrix effect, linearity, accuracy, precision, stability and sensitivity, CC alpha and CC beta according to European Union Decision 2002/657/EC. The proposed method was applied for the analysis of contaminated fish samples after in feed administration of danofloxacin mesylate. (C) 2018 Elsevier B.V. All rights reserved.