Development of Innovative Feed Products and Feed Concepts for Marine Species in Aquaculture

The sustainability challenges of the aquaculture sector will probably be closely linked with continuing interest in ingredients as alternatives to fishmeal for use within aquafeeds. Among the many protein sources available, plant proteins appear to be the most appropriate alternatives. Different aspects on the health implications of using vegetable feed ingredients on the digestive tract, plus possible effects on quality of the fish, are some of the most relevant problems currently confronting the aqua industry. The need to understand this phenomenon leads to the present thesis, in which the investigation on the feasibility of the inclusion of plant protein in aquafeed was undertaken through a multidisciplinary approach. The first study highlighted that inclusion of soybean meal in combination with different blends of plant protein maintains optimal growth in 20% fish meal dietary level for the on-growing of European sea bass. Despite fiber is considered as a component that cannot be utilized by most fish, inclusion up to 9.3% has no effects on growth, feed efficiency and digesta transit time in European sea bass. It was encouraging to note that inclusion of high levels of plant protein sources and fiber did not affect health and nutritional status of the animals. When replacing fish meal in aquafeeds, besides the research on alternative ingredients, also the nutritional profile should be considered. In the third study, it was demonstrated that taurine is a required nutrient for juvenile Southern flounder. The fourth study, highlighted that increasing the inclusion of plant ingredients, in substitution of fish meal, had no effects on quality traits of the commercial product. However, it is not yet an easy or economi¬cally feasible task to reduce the aquaculture dependence from marine feedstuff, the present thesis has contributed to provide some insights on the feasibility of the replacement of fish meal in aquafeed

Effects of dietary lipid level on growth and feed utilisation of gilthead seabream (Sparus aurata L.) reared at Mediterranean summer temperature

We investigated the effects of different dietary lipid levels on gilthead seabream, Sparus aurata, reared at Mediterranean summer temperature. Sixty fish (average weight 75 g) per tank were randomly distributed, in triplicate groups, in a recirculating rearing system (27\ub11\ub0C) and fed ad libitum five isonitrogenous (46% dietary protein) diets with increasing lipid level (16, 18, 20, 22 and 24% named D16, D18, D20, D22 and D24, respectively), over 89 days. Specific growth rate and final body weight were not affected by dietary lipid levels. Feed conversion ratio was significantly higher (P 640.05) in D16 as compared to the other treatments, most likely due to the shortage of dietary energy supply, coped with a significantly higher voluntary feed intake. Consequently, we obtained a significantly lower protein efficiency ratio and gross protein efficiency in D16. Gross lipid efficiency was significantly higher in D16 and D18 than in the other treatments. Biometric parameters and lipase activity in gut content were not influenced by dietary treatments. In conclusion, D18 seems the most suitable diet for gilthead seabream reared at Mediterranean summer temperature, providing both the lowest fish in fish out (FIFO) ratio and a protein sparing effect, which makes gilthead seabream\u2019s production economically and environmentally more sustainable

Effects of light intensity on growth, feeding activity and development in common sole (Solea solea L.) larvae in relation to sensory organ ontogeny

The effects of four light intensities (1000 lx, 500 lx, 50 lx, 3 lx) on growth, survival and feeding activity in common sole (Solea solea L.) larvae were studied from 4 to 51 days post hatching (dph). During the pelagic larval stage (4\u201312 dph), larvae reared at 3 lx showed a lower growth. From 19 onwards, the larvae reared under 3 lx displayed a significant (P 64 0.05) higher SGR than the other treatments and a higher final weight compared to 1000 lx and 500 lx. Survival rate was higher under intermediate light intensities (500 and 50 lx). Larvae reared at 3 lx displayed a significant delay in the degree of metamorphosis compared to the other treatments, while at 33 dph metamorphosis was completed under all treatments. Histological examination revealed the importance of vision and light in the first feeding of this species, while after metamorphosis, the full development of other sensory organs indicated that feeding activity is also mediated by chemosensory perception. Results indicate that high light intensity seems to be more suitable during the pelagic larvae, while the opposite would ensure better growth from the onset of metamorphosis to the benthic phas

Farmed and wild common sole (Solea solea L.): Comparative assessment of morphometric parameters, processing yields, selected nutritional traits and sensory profile

Recent important developments in sole aquaculture have increased the availability of the farmed product on the market. The aim of this research was to characterize and compare for the first time in common sole (Solea solea) morphometric parameters, nutrients and sensory traits of cultured and wild specimens. Farmed sole, while maintaining the characteristics of a lean fish species (2% of lipid content), displayed a EPA+DHA fillet content more than twice as high as its wild counterpart. Sensory traits of \u201cpotato\u201d \u201cboiled fish\u201d sweet, firmness, astringency, chewiness, were correlated to farmed origin while whiteness, briny, \u201coctopus\u201d \u201ccrab\u201d salty, acid, bitter, umami, intensity and juiciness were linked to wild origin. Intensive farming conditions improved the nutritional value of common sole in terms of lipid content and fatty acid profile and led to sweeter sensory traits particularly associated with a terrestrial vegetable perception

Lipids and fatty acids composition of eggs in relation to larval quality from cultured common sole (Solea solea) broodstock

Eggs quality optimization is a fundamental aspect in the standardization of the production cycle of a fish species. Lipids content and fatty acids composition of common sole (Solea solea) eggs were measured and correlated to eggs and larval viability parameters along an entire reproductive season. Seventeen batches of fertile eggs obtained from natural spawning of captive breeders were characterized for lipid content (L), fatty acids content (FAs), total weight (TW), spawning temperature (T), floating rate (FR), hatching rate (HR) and survival rate of larvae (SR) at 0-6 days post hatching (dph). Based on univariate regression models it was possible to formulate significant relations using L, FAs, TW and T as independent variable. T, L, and 20:5(n-3)+20:4(n-6) (EPA+ARA), were significant (P≤0.05) correlated to FR. T, 14:0, 18:0, 22:6(n-3) (DHA), ∑monounsaturated FAs, ∑polyunsaturated FAs of the (n-3) series, and EPA+ARA were significant correlated to HR and SR. It was also found that L, 16:0, 16:1(n-7), 18:2(n-6), 20:4(n-6), saturated FAs, ∑polyunsaturated FAs of the (n-6) series had a significant effect to HR, while TW, 18:1(n-7), 20:5(n-3), ∑(n-6)/∑(n-3), DHA/EPA were significant correlated to SR. The results indicate that quantitative eggs lipids and fatty acids composition can predict eggs and larval quality of common sole. Since breeders’ diet is one of the main factors affecting eggs composition, the results of this study could provide useful information for broodstock nutrition

Molecular Characterization of Circulating Tumor DNA in Pediatric Rhabdomyosarcoma: A Feasibility Study

Rhabdomyosarcomas (RMS) are rare neoplasms affecting children and young adults. Efforts to improve patient survival have been undermined by a lack of suitable disease markers. Plasma circulating tumor DNA (ctDNA) has shown promise as a potential minimally invasive biomarker and monitoring tool in other cancers; however, it remains underexplored in RMS. We aimed to determine the feasibility of identifying and quantifying ctDNA in plasma as a marker of disease burden and/or treatment response using blood samples from RMS mouse models and patients