Alicia Estevez

IRTA Institute of Agrifood Research and Technology | IRTA · Aquaculture Programme

Simple Summary Sustainable strategies for improving blue food economies are essential in order to design a new approach to transitioning towards more responsible, comprehensive, exploitable production and consumption models that have a positive impact on society and the environment. Among different fish farming systems, biofloc technology (BFT) is...

The aim of this study was to evaluate the use of novel ingredients such as green pea protein and Ascophyllum nodosum, a brown seaweed for the replacement of fish meal in feeds suitable for organic production. The growth, feed utilization and fillet composition of gilthead seabream were examined under a lab scale trial and based on the results a lar...

Wild adult females of a low trophic omnivore teleost species, the flathead grey mullet (Mugil cephalus), caught in the western Mediterranean were sampled. The lipid and fatty acid composition of ovaries, liver, muscle, and peritoneal fat were analysed at previtellogenesis, early-vitellogenesis -first observed at mid-summer (early August)-, late-vit...

A trial was conducted to analyze the effect of the inclusion of yeast and spent grain obtained from breweries in feeds for rainbow trout (Oncorhynchus mykiss), taking into account the availability of these by-products, produced in large quantities in Europe. The ingredients were assayed in both dried and hydrolyzed format and compared with a commer...

When designing a new circular economy system, many aspects must be considered in order to benefit from all possible environmental improvements. The selection of the right market or use of the resulting product is of paramount importance to ensure the final implementation of the solution. With this purpose, this study has undertaken the selection of...

With the expansion and diversification of global aquaculture, efforts continue to develop new bio-technologies for assisted reproduction in species that present reproductive dysfunctions. Flathead grey mullet (Mugil cephalus) males held in intensive conditions in the Mediterranean region do not produce fluent milt and most females are arrested at p...

Aquaculture supplies more than 50% of the total fish consumed by the world population. It is considered by FAO authorities that it will be the main source of fishery products by 2030. These positive data are contradicted by the fact that aquaculture relies too much on fish oil and fish meal as essential ingredients for food, which exerts significan...

In this study, we evaluated the replacement of dietary protein sources like fishmeal (FM) and plant proteins (PP) by Brewer’s spent dry yeast (SDY) on the transcriptomic response (RNA-seq, NextSeq500 platform Illumina) in the liver, anterior-mid intestine, and head kidney in juveniles of gilthead sea bream (Sparus aurata). The inclusion of SDY at 3...

Meagre (Argyrosomus regius), is a benthopelagic species rapidly emerging in aquaculture, due to its low food to biomass conversion rate, good fillet yield and ease of production. Tracing a species genomic background along with describing the genetic basis of important traits can greatly influence both conservation strategies and production perspect...

Rotifers are widely used in hatcheries to feed small‐sized aquatic larvae although one of their disadvantages is the lack of zinc and selenium 5‐ and 30‐fold lower than in copepods, respectively. To improve the rotifers quality, different concentrations of zinc and selenium (2, 4, 5 and 10 mg L−1 of each mineral) were added to the medium of the mic...

With the expansion and diversification of global aquaculture, efforts continue to develop new bio-technologies for assisted reproduction in species that present reproductive dysfunctions. Flathead grey mullet ( Mugil cephalus ) held in intensive conditions in the Mediterranean region, display a severe reproductive dysfunction, where males do not pr...

This study aimed to evaluate the effects of alternative feed ingredients: Insect meal (DI) using non-defatted meal obtained from Acheta domesticus, Microalgae (DM) using a mix of four marine microalgae ((Nannochloropsis gaditana, Tisochrysis lutea, Rhodomonas lens, Isochrysis galbana), Protein and oil from water of tuna canning process (DP&L) and a...

Despite the positive role of rotifers in many hatcheries for feeding the early stages of fish larvae and crustaceans, the lower content of minerals such as selenium (Se, 30 times) and zinc (Zn, 5 times) is considered as one of the disadvantages of this live prey compared to copepods. Therefore, increasing the amount of these nutrients through enric...

Two trials were conducted to test the effect of partial replacement of fishmeal by two brewery industry by-products, yeast and spent grain, included in isoproteic and isolipidic diets for gilthead sea bream (Sparus aurata), having in mind the commercial availability of these by-products. According to the obtained results, the inclusion of up to 30%...

The main objective of the present study was to confirm the possible use of these sustainable and food industry by-products as new ingredients in aquafeeds for fast growing species such as meagre

The effects of dietary phospholipids (PL) on the performance of juvenile stellate sturgeon (Acipenser stellatus) was evaluated in terms of growth and feed efficiency parameters, muscle and liver fatty acid profiles, activity of digestive and antioxidative stress enzymes, and expression of lipoprotein lipase (lpl) and insulin-like growth factor (igf...

Essential oils (EOs) are promising alternatives to chemotherapeutics in animal production due to their immunostimulant, antimicrobial, and antioxidant properties, without associated environmental or hazardous side effects. In the present study, the modulation of the transcriptional immune response (microarray analysis) and microbiota [16S Ribosomal...

Low and variable growth and survival rates (SR) of 6-10 days postfertilization zebrafish larvae are a problem. This problem seems to be linked to starter feed characteristics. This study is an attempt to find alternatives to address these requests. For this, larvae were fed fresh and lyophilized microalgae (Chlorella, Scenedesmus, and Haematococcus...

This study was conducted to elucidate the interaction effects of temperature and dietary lipid levels (2 × 2 factorial experiment) on the growth performance, muscle, and liver composition in adult farmed European sea bass (Dicentrarchus labrax). Two groups of fish (190 g; 60 fish per group) were distributed in 12 tanks in triplicates and kept at tw...

Larval rearing and ongrowing of meager have experienced a great advance during the last years and nowadays this species is considered as one of the most important new species in Mediterranean aquaculture. However, larval nutrition in meager still needs some improvements especially regarding live prey enrichment and fatty acid composition. In this s...

A microencapsulated feed additive composed by garlic, carvacrol and thymol essential oils (EOs) was evaluated regarding its protective effect in gills parasitized by Sparicotyle chrysophrii in Sparus aurata. A nutritional trial (65 days) followed by a cohabitation challenge with parasitized fish (39 days) were performed. Transcriptomic analysis by...

Aquafeeds are formulated to contain all the essential nutrients that fishes need to keep healthy. They are highly dependent on marine ingredients: fish meal and oil. Hence, alternative ingredients which successfully replace these marine ingredients are required to result in sustainable and economical feeds. In this context, brewers’ by-products ari...

A nutritional study was conducted to evaluate the inclusion of the green microalga Scenedesmus sp. at 5% (SCE-5) as an alternative fishmeal ingredient. This microalga was tested with four replicates during 45 days using isolipidic (18%), isoproteic (48%), and isoenergetic (1.9 MJ kg-1) diets. Fish fed Scenedesmus sp. showed similar growth and feed...

A trial was conducted to test the effect of partial replacement of fishmeal by two brewery industry byproducts, yeast and spent grain, included in isoproteic (41% CP) and isolipidic (22% CL) diets for gilthead sea bream (Sparus aurata) and rainbow trout (Oncorhyncus mykiss), having in mind the availability of these byproducts. A first step before a...

The present study is the first report of some representative innate immune genes in meagre (Argyrosomus regius) larvae. This study has specifically focused on the growth period from hatching to the juvenile stage, a critical time in marine fish development when reliance on innate immune mechanisms are required for survival. We report molecular clon...

The present study investigated the effects of soybean lecithin bioencapsulated in adult Artemia franciscana and unenriched Artemia in combination with an inert diet on digestive enzymes activity and reproductive performance in Aequidens rivulatus (green terror cichlid). Eight hundred and ten fish (3.1 ± 0.2 g) were randomly allotted into glass tank...

Oily emulsions containing constant levels of total fatty acids (FAs) and varying eicosapentaenoic acid (EPA) and arachidonic acid (ARA) levels were used to enrich rotifers. Common dentex larval survival and growth were compared between groups fed different enriched live prey. Growth, survival rate, and lipid composition of larvae suggest that feedi...

Marine fish larvae and crustaceans need, during the first periods of larval life, to be fed with zooplankton reared with the use of microalgae (phytoplankton) and enriched with omega-3 fatty acids using specialized products. On the contrary freshwater fish can be fed directly with artificial feeds. Furthermore, one of the most difficult periods of...

Sperm quality is an important topic in general health, chemotherapy, and gamete preservation technology. Fatty acid (FA) composition of membranes, which is influenced by the diet, plays key roles in sperm biology and quality. Dietary supplementation with natural products can be used as a technique to screen potential agents to protect, modify, and...

The egg quality of two common dentex captive broodstocks were monitored for two consecutive years during their natural spawning season. Volume of spawned eggs, volume of buoyant eggs, fertilization rate, egg weight, hatching rate and mortality of larvae were recorded. According to the volume of spawned eggs, the ratio of buoyant eggs spawned, the n...

This study investigates the development of lymphoid organs and mucosal tissues in larval and juvenile meagre, Argyrosomus regius. For this purpose, meagre larvae were reared from hatch to the juvenile stage, under mesocosm conditions at 18-19 °C, using standard feeding sequences with live prey and artificial food. The kidney was evident upon hatch...

Análisis sensorial de cinco especies de espáridos (besugo, dentón, hurta, pargo y sargo picudo) en ocho localidades costeras españolas. Resumen. El objetivo del presente estudio ha sido conocer la valoración de las nuevas especies de espáridos por el consumidor. Para ello, se realizó una prueba de aceptación sobre 5 especies de espáridos: besugo, d...

Meagre (Argyrosomus regius), a teleost fish of the family Sciaenidae, is part of a group of marine fish species considered new for Mediterranean aquaculture representing the larger fish cultured in the region. Meagre aquaculture started ~25years ago in West Mediterranean, and the supply of juveniles has been dominated by few hatcheries. This fact h...

The on-growing of tench Tinca tinca fry (1.81 ± 0.6 g) and grey mullet Mugil cephalus fry (0.65 ± 0.2 g) was carried out using two different culture systems, recirculation aquaculture system (RAS) and biofloc technology culture system (BFT), to compare their performance and evaluate the technical feasibility of rearing both species using an alterna...

Antimicrobial peptides (AMPs), components of innate immunity, play an important role in protecting fish. In this study we report the molecular cloning of full open reading frames and characterization of expression of three AMP genes (β-defensin (defb), hepcidin (hep2), piscidin (pisc) in meagre (Argyrosomus regius). A phylogenetic analysis of the e...

Fish are ectotherms and temperature plays a determinant role in their physiology, biology and ecology and is a driver of seasonal responses. The present study assessed how thermal imprinting during embryonic and larval stages modified the response of adult fish to low water temperature. We targeted the gilthead sea bream that develops a condition k...

Microorganisms present in the rearing water colonize the gut of first feeding larvae and represent the first barrier against opportunistic pathogens. The aim of the experiments presented herein was to standardize a protocol for the management of rearing water and microalgae suitable for the larval rearing of common dentex. In Experiment 1, bacteria...

While spawning induction and larval rearing of meagre (Argyrosomus regius) have advanced as forcing factors to move this finfish species into the commercial aquaculture sector, larval nutrition still has unanswered issues to address, specifically in regard to live prey enrichment and fatty acid composition. In this study, two experimental trials fo...

In species with complex life cycles, laboratory studies have shown that variations in the traits of settling larvae can affect post-settlement survival and influence recruitment and benthic- pelagic coupling. However, we still know little about the magnitude and spatial scale of natural trait variation. We studied spatial variation in body size and...

Meagre Argyrosomus regius is considered a new species for the diversification of finfish aquaculture in the Mediterranean. Several bottlenecks have been identified by producers, and among them, the necessity to establish early weaning protocols to reduce production costs. In this study, two experiments were carried out with meagre larvae from 2 to...

The impact of thermal imprinting during development on the plasticity of the hypothalamic-pituitary-interrenal (HPI) axis and stress response in an adult ectotherm, the gilthead sea bream (Sparus aurata, L.), was assessed. Fish were reared under 4 thermal regimes and the resulting adults exposed to acute confinement stress and plasma cortisol level...

The common octopus (Octopus vulgaris) is a promising species for aquaculture diversification, but massive mortality during the first life-cycle stages (paralarvae) is the main bottleneck for its commercial production in captivity. The aim of this study was to assess stress and nutritional condition biomarkers (HSP70, ROS enzymes and lipid peroxidat...

Five variables relating to the enrichment of live prey were studied using experimental micellar emulsions. Rotifers and Artemia nauplii were enriched for 12 and 24 hrs, respectively, and sampled at several intervals to analyse their fatty acid profile and determine the better time length for enrichment. Two hour and 18 hr were shown to be the most...

Vegetable oils (VO) are increasingly used to substitute fish oil (FO) in aquafeeds in order to meet demands of the rapidly growing aquaculture industry. However, effects of dietary VO on appetite and food intake have hardly been investigated, despite the importance of these factors for determining growth and body composition of cultured fish. This...

The gilthead sea bream (Sparus aurata L.) is one of the most important Sparid farmed in Europe, especially in the Mediterranean area. However, efficient breeding programs for this species are scarce and very little, and it is known concerning their population structure. The present study was mainly designed to genetically characterize, by microsate...

Lordosis, lack of operculum and failure to inflate the swimbladder constitute a major problem for the gilthead sea bream aquaculture industry. In this study, the effect of the origin of the broodstock on these major anomalies in juvenile sea bream was analyzed. A population of farmed sea bream (n = 909) obtained by industrial mass-spawning from bro...

The morphological and functional development of the digestive system in meagre (Argyrosomus regius, Asso, 1801) was described by means of histological and enzymatic approaches in order to provide insight into the digestive physiology of the species at early life stages of development and evaluate whether the acquisition of digestive capacities matc...

A method for studying the efficacy of sulfadiazine as a marker to estimate feed intake is presented. Feeding studies were carried out with two species, rainbow trout as a freshwater fish model and gilthead sea bream as a marine fish model, using two temperatures and two sizes of juveniles. The study showed the different feeding behaviour observed i...

Little is known how dietary lipids affect food intake during larval development of fish, especially with regard to fatty acid (FA) composition. In fact, very little work has been done on appetite regulation and food intake in fish larvae in general, due to biological and technical difficulties associated with this type of studies. A new method usin...

The common octopus (Octopus vulgaris, Cuvier 1797) is a promising species for aquaculture diversification, but the massive mortality during the first life stage is the main bottleneck for its commercial production. The aim of the present study was to compare the effects of different live preys (Artemia and crustacean zoeae) and/or Artemia enrichmen...

Recurrent infection of captive meagre, Argyrosomus regius, by a monogenean parasite has been observed in the broodstock facilities of Institut de Recerca i Tecnologia Agroalimentàries (IRTA) in Catalonia, Spain, between 2008 and 2015. Following handling procedures related with hormonal treatment for spawning induction, one fish died. Post-mortem ex...

To date, most research on larval lipid nutrition has been centered on essential fatty acid requirements. However, less is known about effects of dietary fatty acid (FA) composition on lipid absorption and metabolism, as addressed in this study. Senegalese sole were fed live preys enriched with different oils: cod liver oil (CLO), linseed oil (LSO),...

This study analyses the effects of dietary lipid level and source on lipid absorption and metabolism in Senegalese sole (Solea senegalensis). Juvenile fish were fed 4 experimental diets containing either 100 % fish oil (FO) or 25 % FO and 75 % vegetable oil (VO; rapeseed, linseed and soybean oils) at two lipid levels (~8 or ~18 %). Effects were ass...

This study used meta-analysis to quantitatively review the effect of feeding with different live preys (Artemia and crustacean zoeae) and/or enriched Artemia on the growth of common octopus (Octopus vulgaris) paralarvae through a meta-analysis. A total of 26 independent assays allowed testing for growth differences between: (i) crustacean zoeae vs...

Carcass quality traits such as visceral fat and fish morphology have a direct influence on final product and consumer preferences, especially in species as sea breamthat are sold as whole fish. Nevertheless, strategies that involve the development of selection schemes for these traits of economic interest in gilthead sea bream are limited. In this...

In gilthead sea bream, flesh quality traits such as body composition and texture directly influence yield of final product and consumer preferences so they should be considered in the breeding goal. However, strategies that involve the development of selection schemes for these traits of economic interest are scarce. Taking into account these circu...

Growth rates and the presence of deformities can be affected by the use of different rearing systems aswell as by the different genetic origins of the stocks. At the same time, strategies that involve the development of selection schemes for these traits of economic interest are scarce. In this study the effect of the origin of the broodstock on gr...

The spider crab Maja brachydactyla is an important fisheries species in Europe. Adults were sampled in R�ıa de A Coru~na (NW Spain) and transported to IRTA rearing facilities. Salinity and photoperiod changes and their effect on repro- duction were tested in the laboratory. The number of newly hatched larvae per batch (presence of actively swimming...

Live prey used in aquaculture to feed marine larval fish – rotifer and Artemia nauplii – lack the necessary levels of n-3 polyunsaturated fatty acids (n-3 PUFA) which are considered essential for the development of fish larvae. Due to the high voracity, visual feeding in conditions of relatively high luminosity, and cannibalism observed in meagre l...

One of the most important problems of fish aquaculture is the high incidence of fish deformities, which are mainly skeletal. In this study, genetic parameters on gilthead seabream (Sparus aurata L.) for skeleton deformities at different ages (179, 269, 389, 539 and 689 days) and their correlations with growth traits were estimated, as were as their...

Live prey used for marine larval fish (rotifers and Artemia) as well as intensive larval rearing conditions are susceptible to the proliferation of bacteria that are the cause for reduced growth and larval mortality. Hydrogen peroxide has been recently proved a good disinfectant in aquaculture, either for eggs, larvae or live prey. In this study th...

The spider crab Maja brachydactyla is an important fisheries species in Europe. Adults were sampled in R�ıa de A Coru~na (NW Spain) and transported to IRTA rearing facilities. Salinity and photoperiod changes and their effect on repro- duction were tested in the laboratory. The number of newly hatched larvae per batch (presence of actively swimming...

The spider crab Maja brachydactyla is an important fisheries species in Europe. Adults were sampled in R�ıa de A Coru~na (NW Spain) and transported to IRTA rearing facilities. Salinity and photoperiod changes and their effect on reproduction were tested in the laboratory. The number of newly hatched larvae per batch (presence of actively swimming n...

Aquaponics is a combination of both hydroponics and aquaculture. Marine aquaponics system applies this technology with marine aquatic organisms and plants that can be grown in sea water systems.

Recirculation was initially developed as a direct consequence of the problems generated by the need to work beyond the limits set by the natural environment and in more than one specific period of the year. For instance, it seems unthinkable to maintain productivity levels during the winter without incurring prohibitive energetic costs.

Senegalese sole was one of the earliest identified candidate species with high potential for aquaculture diversification in the south of Europe. Its culture has been possible, and commercially attempted, for several decades, but intensive production has been slow to take off. This has been explained mostly by serious disease problems, high mortalit...

High dietary levels of arachidonic acid (ARA) and its relative proportions with eicosapentaenoic acid (EPA), fed during early larval stages, have been associated with malpigmentation in various flatfish species. This study investigated whether the nutritional induction of pigmentary disorders at larval stages was related to a specific larval period...

Flatfish can provide a reliable model to study developmental disorders in bone tissues occurring during morphogenesis in response to nutritional imbalances. To date, most studies dealing with the effect of dietary essential fatty acids (EFA) on skeletogenesis in fish have focused their investigation on the role of docohexanoic (22:6n−3, DHA) and ei...

In this study we evaluated the effects of high dietary arachidonic acid (ARA) levels on prostaglandin E-2 (PGE(2)) and E-3 (PGE(3)) production and their effect on two morphogenetic processes occurring during metamorphosis: the establishment of the juvenile pigmentation pattern and eye migration and remodeling of cranial bones. In this sense, Senega...

Live prey used for marine larval fish (rotifers and Artemia) as well as intensive larval rearing conditions are susceptible to the proliferation of bacteria that are the cause for reduced growth and larval mortality. Hydrogen peroxide has been recently proved a good disinfectant in aquaculture, either for eggs, larvae or live prey. In this study th...

Fish tissues, particularly rich in n-3 PUFA, are prone to lipid peroxidation that can damage cellular membranes, cause severe lesions and subsequently incidences of disease and mortality. However, fish possess antioxidant defences, such as vitamin E (VE) and antioxidant enzymes, to protect them against oxidative damage. This study investigated the...