Global aquaculture growth will most probably face specific conditions derived from climate change. In fact, the most severe impacts of these changes will be suffered by aquatic populations in ...restrictive circumstances, such as current aquaculture locations, which represent a perfect model to study global warming effects. Although the impact of temperature on fish reproduction has been characterized in many aspects, this study was focused on recreating more realistic models of global warming, particularly considering heatwave phenomena, in order to decipher its effects on male gametes (spermatozoa). For this purpose, thermal stress via a heatwave simulation (mimicking a natural occurring heatwave, from 24 to 30 °C) was induced in adult tench (
) males and compared with a control group (55.02 ± 16.44 g of average body wet weight). The impact of the thermal stress induced by this climate change event was assessed using cellular and molecular approaches. After the heatwave recreation, a multiparametric analysis of sperm quality, including some traditional parameters (such as sperm motility) and new ones (focus on redox balance and sperm quality biomarkers), was performed. Although sperm concentration and the volume produced were not affected, the results showed a significant deleterious effect on motility parameters (e.g., reduced progressive motility and total motility during the first minute post-activation). Furthermore, the sperm produced under the thermal stress induced by this heatwave simulation exhibited an increased ROS content in spermatic cells, confirming the negative effect that this thermal stress model (heatwave recreation) might have had on sperm quality. More importantly, the expression of some known sperm quality and fertilization markers was decreased in males exposed to thermal stress. This present study not only unveils the potential effects of climate change in contemporary and future fish farming populations (and their underlying mechanisms) but also provides insights on how to mitigate and/or avoid thermal stress due to heatwave events.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, UILJ, UKNU, UL, UM, UPUK
High dietary SBM content is known to induce important physiological alterations, hampering its use as a major FM alternative. Rainbow trout (
) juveniles were fed two experimental diets during 9 ...weeks: (i) a FM diet containing 12% FM; and (ii) a vegetable meal (VM) diet totally devoid of FM and based on SBM (26%). Fish fed the VM diet did not show reduced growth performance when compared with fish fed the FM diet. Nevertheless, fish fed the VM diet had an increased viscerosomatic index, lower apparent fat digestibility, higher aminopeptidase enzyme activity and number of villi fusions, and lower α-amylase enzyme activity and brush border integrity. Small RNA-Seq analysis identified six miRs (omy-miR-730a-5p, omy-miR-135c-5p, omy-miR-93a-3p, omy-miR-152-5p, omy-miR-133a-5p, and omy-miR-196a-3p) with higher expression in blood plasma from fish fed the VM diet. Bioinformatic prediction of target mRNAs identified several overrepresented biological processes known to be associated with high dietary SBM content (e.g., lipid metabolism, epithelial integrity disruption, and bile acid status). The present research work increases our understanding of how SBM dietary content has a physiological impact in farmed fish and suggests circulating miRs might be suitable, integrative, and less invasive biomarkers in fish.
Aquaculture’s sustainability deeply relies on the identification and inclusion of alternative raw materials. Although meals from insects and/or byproducts from different industries are being recently ...tested, the meal from terrestrial vegetable species is still the main substitution candidate for fish meal. Here the effects of 0% (Control), 10% (A10) and 30% (A30) inclusion of Narbonne vetch (Vicia narbonensis; ZV-156 strain) meal in rainbow trout (Oncorhynchus mykiss) diets was assessed in a 63-day feeding trial by means of growth performance, histopathological, nutritional value of the fish fillet and blood biochemistry analyses. A dose-response trial was conducted in triplicate with 25 rainbow trout juveniles (20 g average body weight) per 500 L tank. Narbonne vetch meal decreased total intestine protease activity in vitro (from 26.81% to 48% inhibition), although high temperature partially inhibited the action of antinutritional factors (ANFs). No differences in fish growth performance and no severe histopathological alterations on the proximal intestine were observed between 10% Narbonne vetch inclusion and Control groups. In contrast, high inclusion (30%) of Narbonne vetch led to poor growth performance (30% reduction on final growth) and severe histopathological alterations (e.g., loss of brush border integrity, high number of villi fusion, reduced goblet cells density as well as reduced width of submucosa, muscular and serosa layers). Furthermore, while the A30 diet decreased docosahexaenoic fatty acid (FA) content in fish fillets, the A10 diet improved monounsaturated FA content when compared to that of the Control group. No altered levels of cholesterol, glucose or triglycerides in blood plasma and/or histopathological effects on the liver were observed among fish fed the different experimental diets. Although further research efforts (e.g., identifying potential enzymatic treatments to decrease the action of ANFs from Narbonne vetch meal) might be required, present results show that a low inclusion (10%) of Narbonne vetch in rainbow trout diets is possible. The inclusion of locally produced legumes such a Narbonne vetch might be an interesting approach to reduce carbon footprint in European aquaculture and the dependency on other alternative raw materials such as soybean (Glycine max) imported from third countries.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, UILJ, UKNU, UL, UM, UPUK
Skeletal deformities reduce fish viability, growth, wellbeing, and feed efficiency but also degrade the consumer's perception of aquaculture products. Herein, the skeletal development and the ...incidence of skeletal deformities in tench (
) reared in semi-extensive conditions has been described in detail for the first time. Larval skeletons were assessed through an acid-free double-staining procedure in 157 individuals, while 274 specimens at the juvenile stage were evaluated through X-ray analysis. The first skeletal structures to be formed were those related with breathing and feeding activities (e.g., Meckel's cartilage and opercula) and were visible in larvae of 4 mm of standard length (SL). The axial skeleton was fully ossified in larvae of 12-17 mm of SL, and the caudal fin complex in larvae with 17-26 mm of SL. At the larval stage, no upper-jaw or opercula deformities were observed, while a low incidence (1-9%) of other severe deformities in the heads of the fish (e.g., lower-jaw deformities) were reported. The incidence of vertebral deformities in tench reared in natural ponds was considerable in larvae (54%) and juveniles (52%). Vertebral deformities (fusion and compression) were the most common deformities found in tench larvae (approximately 30%) and vertebral shape deformity in juveniles (around 10%), being mainly located in the caudal region. Thus, a regular monitoring of the skeletal deformities in tench might help to identify better rearing protocols and improve product quality sold at markets. Characterizing the skeletal development not only in semi-extensive systems such as artificial and natural ponds but also under intensive rearing conditions, seems vital for a sustainable and profitable European tench aquaculture.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, UILJ, UKNU, UL, UM, UPUK
Aquaculture growth and sustainability mainly rely on the identification and implementation of alternative raw materials to replace fish meal (FM) and fish oil (FO) and/or its major substitute, the ...soybean meal (SBM). A five-step screening tool has been designed to identify and improve the use of promising alternative raw materials. To validate it, nine raw materials, including the standard reference (the SBM), were sequentially analyzed regarding (i) the total buffer capacity, alkaline protease activity inhibition and soluble protein content, (ii) soluble phosphorus and phenolic compound content, (iii) modification of nutrients bioavailability and presence of anti-nutritional factors after treatment with exogenous enzyme (Rovabio® Phy), (iv) release of nutrients after in vitro digestion, and (v) the palatability of the formulated diet. SBM partial replacement by selected raw material, the Narbonne vetch (Vicia narbonensis) meal (NVM), was evaluated in a 63-day nutritional trial using rainbow trout (Oncorhynchus mykiss) juveniles. One Control (no SBM replacement) and 4 experimental diets with SBM replacement in two levels (33% and 66%), treated or not with exogenous enzyme Rovabio® Phy, were compared. Fish growth performance and amino acid profile in fish fillet was not significantly affected when SBM was replaced by 33% of NVM treated with exogenous enzyme. Altogether, the present screening tool might be a wise strategy to identify promising alternative raw materials for European aquaculture sustainability, reducing the use of animals in experimentation, the SBM dependency from third countries, and its carbon footprint.
•A specific multiparametric screening tool allows to identify and improve the use of promising alternative raw materials.•The tool discriminates different cultivars and/or pre-treatments applied.•The costs and the use of animals in experimentation may be reduced with this screening tool.•This screening tool represents an important step forward towards the reduction of the EU dependency on soybean meal from third countries.
The identification and implementation of raw materials to replace fish meal (FM) or its major alternative, soybean meal (SBM), among other factors, is crucial for the sustainable growth of ...aquaculture. Narbonne vetch (Vicia narbonensis) meal (NVM) has previously been identified as a promising alternative raw material locally produced in Europe to replace SBM. Previous work has showed that 33% replacement of SBM by NVM treated with a commercially available phytase (Rovabio® PHY) does not compromise fish growth performance in a 63-day trial. Here, a deeper characterization of the potential use of NVM to replace SBM was performed to unveil any potential undesired physiological impact in rainbow trout (Oncorhynchus mykiss) juveniles with an initial weight of 38.04 ± 0.07 g. After a 63-day feeding trial, high (66%) SBM replacement by NVM (even when treated with Rovabio® PHY) had a negative impact on rainbow trout: decreasing the activity of alkaline proteases, trypsin, chymotrypsin, and α-amylase; inducing cell shrinkage in hepatocytes; and reducing plasma triglycerides and hepatic vitamin E (VE) levels. No biochemical alterations were observed in blood plasma glucose, cholesterol or redox enzymes, regardless of the % of SBM replacement and/or Rovabio® PHY treatment. In fish fed diets with 33% replacement of SBM by NVM (regardless of being treated with Rovabio® PHY or not), only a reduced content of plasma triglycerides, and a slight modification in the position of the nucleus in enterocytes (more intermediate) from the proximal intestine, were reported. Altered metabolism of both carbohydrates and VE was also confirmed at transcriptional level, possibly being related to the presence of non-starch polysaccharides (NSPs) in NVM. The present study identifies future strategies to improve the use of NVM as an alternative raw material to replace SBM, allowing greater sustainability, and a lower carbon footprint in European aquafeeds to be achieved.
•Locally produced crops might reduce European’s SBM dependency and carbon footprint.•High SBM replacement by Narbonne vetch meal (NVM) reduce protein and carbohydrates digestion.•SBM replacement by NVM decreased plasma triglycerides and hepatic vitamin E (VE).•Glucose and VE uptake and metabolism were altered at transcriptional level.•Presence of non-starch polysaccharides might limit SBM replacement by NVM.
Spermatozoal haplotypic DNA is prone to damage, leading to male fertility problems. So far, the assessment of sperm DNA breakage has been challenging because protamines render the nuclear chromatin ...highly compacted. Here, we report the application of a new test to quantify DNA fragmentation in spermatozoa of an externally fertilizing teleost fish. The sperm chromatin dispersion (SCD) test uses a species-specific lysing solution to generate controlled protein depletion that, followed by DNA-specific fluorescent labelling, allows an easy morphological discrimination between nuclei affected by DNA damage. Using tench (Tinca tinca) as our model, we first trialled the test against established, but more technically demanding, assays employing in situ nick translation (ISNT) and the comet assay. The SCD test showed high concordance with ISNT, comet assay measures and a chromatin-swelling test, confirming the application of this straightforward SCD technique to various aspects of reproductive biology. Second, we examined between-male variation in DNA damage, and measured changes through time following spermatozoal activation. Between-male variation in the basal levels of average DNA damage ranged from 0 to 20% of sperm showing damage, and all showed increases in DNA fragmentation through time (0-60 min). The rates of DNA damage increase are the fastest so far recorded in sperm for a living organism, and may relate to the external fertilization mode. Our findings have relevance for broodstock selection and optimizing IVF protocols routinely used in modern aquaculture.
The present study assessed the criteria for initiating cytoreduction and response to conventional therapies in 1446 patients with essential thrombocythemia (ET), 267 (17%) of which were CALR‐mutated. ...In low risk patients, time from diagnosis to cytoreduction was shorter in CALR‐positive than in the other genotypes (2·8, 3·2, 7·4 and 12·5 years for CALR, MPL, JAK2V617F and TN, respectively, P < 0·0001). A total of 1104 (76%) patients received cytoreductive treatment with hydroxycarbamide (HC) (n = 977), anagrelide (n = 113), or others (n = 14). The estimated cumulative rates of complete haematological response (CR) at 12 months were 40 % and 67% in CALR and JAK2V617F genotypes, respectively. Median time to CR was 192 days for JAK2V617F, 343 for TN, 433 for MPL, and 705 for CALR genotypes (P < 0·0001). Duration of CR was shorter in CALR‐mutated ET than in the remaining patients (P = 0·003). In CALR‐positive patients, HC and anagrelide had similar efficacy in terms of response rates and duration. CALR‐mutated patients developed resistance/intolerance to HC more frequently (5%, 23%, 27% and 15% for JAK2V617F, CALR, MPL and TN, respectively; P < 0·0001). In conclusion, conventional cytoreductive agents are less effective in CALR‐mutated ET, highlighting the need for new treatment modalities and redefinition of haematologic targets for patients with this genotype.
Aquaculture's sustainability deeply relies on the identification and inclusion of alternative raw materials. Although meals from insects and/or byproducts from different industries are being recently ...tested, the meal from terrestrial vegetable species is still the main substitution candidate for fish meal. Here the effects of 0% (Control), 10% (A10) and 30% (A30) inclusion of Narbonne vetch (Vicia narbonensis; ZV-156 strain) meal in rainbow trout (Oncorhynchus mykiss) diets was assessed in a 63-day feeding trial by means of growth performance, histopathological, nutritional value of the fish fillet and blood biochemistry analyses. A dose-response trial was conducted in triplicate with 25 rainbow trout juveniles (20 g average body weight) per 500 L tank. Narbonne vetch meal decreased total intestine protease activity in vitro (from 26.81% to 48% inhibition), although high temperature partially inhibited the action of antinutritional factors (ANFs). No differences in fish growth performance and no severe histopathological alterations on the proximal intestine were observed between 10% Narbonne vetch inclusion and Control groups. In contrast, high inclusion (30%) of Narbonne vetch led to poor growth performance (30% reduction on final growth) and severe histopathological alterations (e.g., loss of brush border integrity, high number of villi fusion, reduced goblet cells density as well as reduced width of submucosa, muscular and serosa layers). Furthermore, while the A30 diet decreased docosahexaenoic fatty acid (FA) content in fish fillets, the A10 diet improved monounsaturated FA content when compared to that of the Control group. No altered levels of cholesterol, glucose or triglycerides in blood plasma and/or histopathological effects on the liver were observed among fish fed the different experimental diets. Although further research efforts (e.g., identifying potential enzymatic treatments to decrease the action of ANFs from Narbonne vetch meal) might be required, present results show that a low inclusion (10%) of Narbonne vetch in rainbow trout diets is possible. The inclusion of locally produced legumes such a Narbonne vetch might be an interesting approach to reduce carbon footprint in European aquaculture and the dependency on other alternative raw materials such as soybean (Glycine max) imported from third countries. Keywords: antinutritional factors; legume; local crops; vegetable meal Aquaculture's sustainability deeply relies on the identification and inclusion of alternative raw materials rather than continuing with the use of finite resources such as fish meal and fish oil. Different alternative raw materials have been tested, with the meal from terrestrial vegetable species being one of the main substitution candidates for fish meal. This study evaluated the effects of the inclusion (at 0%, 10% and 30%) of Narbonne vetch (Vicia narbonensis) meal in rainbow trout (Oncorhynchus mykiss) diets as a first attempt to evaluate its safety as a suitable alternative raw material. High inclusion (30%) of Narbonne vetch led to a reduced final fish size and weight. This seemed to be due to severe histopathological alterations in the proximal intestine that might alter the capacity of the fish to efficiently use the nutrients supplied by the diet. In contrast, a 10% inclusion did not affect fish growth nor digestive system and/or the nutritional value of the fish fillet. Although further research efforts might be required to increase the utilization of alternative raw materials locally produced like Narbonne vetch, present results show Narbonne vetch might reduce carbon footprint in European aquaculture and the dependency on other alternative raw materials such as soybean (Glycine max) imported from third countries.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, UILJ, UKNU, UL, UM, UPUK
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