Ignacio Ruiz-Jarabo

• PhD
• Researcher at Spanish National Research Council

Simple Summary This study investigated the response of goldfish (Carassius auratus) to different management conditions by assessing their oxygen consumption using an intermittent respirometry system, which serves as an indicator of metabolic rate. Goldfish consumed more oxygen during the day than at night, agreeing with the diurnal pattern of this...

Simple Summary Seahorses are iconic species facing population decline due to human action. Knowledge about seahorse distribution in Europe, particularly along the southwest coasts, remains scarce. This work has gathered information from diverse sources, including scientists, managers, professional fishermen, and the invaluable citizen-science platf...

Simple Summary Artisanal fishing constitutes a subsistence activity in much of the world. Changes in fishing legislation can damage the sector if rapid adaptations are not achieved. As Europe demands landing of all catches, except those whose survival is scientifically proven, this study proposes possible improvements for the sector through a pilot...

Simple Summary Calcium regulation in body fluids is a fundamental process in vertebrates, which is exerted by a plethora of hormones. Stanniocalcin (STC) is a hypocalcemic hormone ubiquitously expressed in tetrapods; in bony fishes, it is produced mainly by specific glands called the corpuscles of Stannius. The present study described an ELISA meth...

In this study, we assessed the effect of environmental salinity and pH as independent factors on larval survival of Atlantic bluefin tuna (ABFT –Thunnus thynnus) together with their whole-body Na⁺/K⁺-ATPase and v-type H⁺-ATPase activities. Fertilized eggs of ABFT were obtained from a spontaneous spawning of broodstock in the farming facilities at E...

Simple Summary In catsharks (Scyliorhinus canicula), air exposure induces amino acid catabolism altogether with osmoregulatory imbalances. This study describes a novel NHE isoform being expressed in gills that may be involved in ammonium excretion. Abstract Acute-stress situations in vertebrates induce a series of physiological responses to cope w...

Simple Summary For the first time, glucocorticoid actions of corticosteroids are evidenced in vivo and ex vivo in sharks, highlighting the importance of carbohydrate metabolism in situations of high-energy expenditure in this taxonomical group. Long-term (7 days) in vivo administration of dexamethasone (DEX, a synthetic glucocorticoid) decreased 1α...

Cortisol is the main glucocorticoid hormone promoting compensatory metabolic responses of stress in teleosts. This hormone acts through genomic and membrane-initiated actions to exert its functions inside the cell. Experimental approaches, using exogenous cortisol administration, confirm the role of this hormone during short (minutes to hours)- and...

Evaluating the survival of discarded species is gaining momentum after the new European Common Fisheries Policy (Article 15 of the European Regulation No. 1380/2013). This regulation introduced a discard ban, with an exemption for those species with demonstrated high survival rates after their capture and release. Candidate species should be evalua...

The genus Coris contains 28 valid species, most of them with an Indo-Pacific distribution and only two species recognized from the eastern Atlantic: Coris atlantica and C. julis. This last species has a large variability in its coloration, which caused that during the first half of XIX century the sexes were considered as different species. Two liv...

The use of lysed microalgae in the diet of carnivorous fish can increase the bioavailability of proteins and bioactive compounds, such as unsaturated fatty acids or vitamins in the digestive tract. These are essential molecules for the proper physiological development of fish in aquaculture. However, some antinutritional components and other undesi...

The effects of ocean acidification mediated by an increase in water pCO2 levels on marine organisms are currently under debate. Elevated CO2 concentrations in the seawater induce several physiological responses in teleost fish, including acid-base imbalances and osmoregulatory changes. However, the consequences of CO2 levels enhancement on energy m...

Simple Summary Ensuring a good quality of life for animals is a matter of concern. Welfare assessment has been quite well developed for many terrestrial species, but it is less well characterized for aquatic animals. Classic methodologies, such as behavioral observation, seem unable to improve the wellbeing of aquatic animals when used alone, mainl...

The intestine of marine fishes contributes to the ocean carbon cycle producing carbonate aggregates as part of the osmoregulatory process. Therefore, this study aimed to evaluate physiological adjustments of European sea bass (Dicentrarchus labrax) intestine to a higher pCO2 environment likely in the near future (~1700 μatm). At the whole-body leve...

The improvement of aquaculture industry is directly linked to the improvement of fish welfare, as better growth rates are related to low-stress conditions for fish. In aquaculture facilities, routine processes such as live transportation activate the stress response compromising welfare of fish. As a solution, the use of anesthetics seems to reduce...

Stress responses in teleosts include the release of hormones into the bloodstream. Their effects depend on the species and on the environmental conditions. The Amazon basin collects waters of diverse chemical composition, and some fish are able to inhabit several of them. However, the effects of these waters on the stress axis are still unknown. He...

Fish welfare is gaining momentum due to consumers' trends and legal regulations. Therefore, aquaculture industry is in the way of mitigating stress to the animals and, thus, improving the physiological status, with the consequent increase in economical profits. As a consequence, feed additives have been proposed as potential stress relievers throug...

Sea bream (Sparus aurata Linneaus) was acclimated to three salinity concentrations, viz. 5 (LSW), 38 (SW) and 55psμ (HSW) and three water temperatures regimes (12, 19 and 26 °C) for five weeks. Osmoregulatory capacity parameters (plasma osmolality, sodium, chloride, cortisol, and branchial and renal Na+,K+-ATPase activities) were also assessed. Sal...

The European Fisheries Policy aims at a progressive elimination of discards. An exception from this regulation includes the release of species with high survival rates after capture. In south-western Atlantic waters of Europe, Norway lobster (Nephrops norvegicus) and spottail mantis shrimp (Squilla mantis) are amongst the most important crustacean...

Teleost fish are exposed to diverse stressors in farming and wildlife conditions during their lifespan. Cortisol is the main glucocorticoid hormone involved in the regulation of their metabolic acclimation under physiological stressful conditions. In this context, increased plasma cortisol is associated with energy substrate mobilization from metab...

Fish aquaculture generates stressful situations that reduce animal welfare conditions and the economic benefits. In this article, we expose two possibilities for stress attenuation in the gilthead seabream (Sparus aurata L.), an emblematic species for the national and European aquaculture.

Eleginops maclovinus is a native species with potential for Chilean aquaculture. However, its optimal stocking density and the impact on its physiology is unknown. The aim of this study is to determine the optimal stocking density range by evaluating parameters of growth, stress, intermediary metabolism, and osmoregulation. For this, 48 immature ma...

Glucocorticoids are pleiotropic steroid hormones mediating redistribution of energy. They induce breakdown of glycogen stores and consequent plasma hyperglycaemia after stressful situations. Glucocorticoid actions in most vertebrate species are exerted by cortisol and corticosterone. However, 1α-hydroxycorticosterone is the dominant corticosteroid...

Marine sharks show a differentiated ion composition between their body fluids and the surrounding seawater. It was described that acute stress challenges evoke consumption of energy metabolites and osmoregulatory imbalances, including changes in blood Na + , Cl-and K + levels. Recovery to basal concentration of these ions is mostly due to osmorgula...

Several Octopodidae species have a great potential for the diversification of worldwide aquaculture. Unfortunately, the lack of stress-related biomarkers in this taxon results an obstacle for its maintenance in conditions where animal welfare is of paramount relevance. In this study, we made a first approach to uncover physiological responses relat...

Marine fish contribute to the carbon cycle by producing mineralized intestinal precipitates generated as by-products of their osmoregulation. Here we aimed at characterizing the control of epithelial bicarbonate secretion and intestinal precipitate presence in the gilthead sea bream in response to predicted near future increases of environmental CO...

Transport processes between aquaculture facilities activate the stress response in fish. To deal with these situations, the hypothalamic-pituitary-interrenal (HPI) axis releases cortisol, leading to an increase in circulating energy resources to restore homeostasis. However, if the allostatic load generated exceeds fish tolerance limits, stress-rel...

In aquaculture facilities fish welfare could be compromised due to stressors. Fish deal with stress, inter alia, through the activation of the hypothalamic-pituitary-interrenal endocrine axis and, as a result, corticosteroids are released into the blood. Recent studies have described that corticosteroids actions depend on the specific affinities to...

In 2019, Europe will adopt a no-discards policy in fisheries. This entails the landing of captured species unless strong evidence is provided supporting their survival and recovery after fishing. Thus, research on this topic is gaining momentum. Bottom-trawling, as a non-selective fishing method, is characterized by a high proportion of discards in...

The meagre (Argyrosomus regius), a farmed fish in Mediterranean countries, seasonally migrates from offshore areas to estuaries for reproduction. During the first two years of life, the meagre evidences a certain grade of euryhalinity by staying in brackish waters close to the shore. The aim of the present study was to establish if fingerling growt...

Aquaculture in Europe aims to diversify and optimize fish farming. The meagre (Argyrosomus regius) arose as a promising species due to its fast growth rates and flesh quality. Thus, it is currently being produced in several Mediterranean countries, mainly in sea-cages and salt-marshes. However, although meagre naturally spend the first years of lif...

Sharks are captured by tons for human consumption. Improving the quality of their meat will produce fillets that may have a higher economic value in the market, and thus be beneficial for the management of this fishery. In other animal species destined for human consumption, a negative relationship between pre-slaughtering stress and meat quality h...

In euryhaline teleosts, the hypothalamus-pituitary-thyroid and hypothalamus-pituitary-interrenal axes (HPT and HPI, respectively) are regulated in response to environmental stimuli such as salinity changes. However, the molecular players participating in this physiological process in the gilthead seabream (Sparus aurata), a species of high value fo...

Marine fish contribute to the carbon cycle by producing mineralized intestinal aggregates generated as by-products of their osmoregulation. Here we aimed at characterizing the control of intestinal aggregate production in the gilthead sea bream in response to near future increases of environmental CO2. Our results demonstrate that hypercapnia (800...

Thyroid hormones are involved in many developmental and physiological processes, including osmoregulation. The regulation of the thyroid system by environmental salinity in the euryhaline gilthead seabream (Sparus aurata) is still poorly characterized. To this end seabreams were exposed to four different environmental salinities (5, 15, 40 and 55 p...

Eleginops maclovinus is an endemic, subantarctic Notothenioidei species. This study examined the influence of different environmental salinities (5, 15, and 45 psu; and 32 psu as a control) on energy metabolism in E. maclovinus over a period of 14 days. Metabolite contents and enzymatic activities related to carbohydrate, amino acid, and lipid meta...

Background Marine species have colonized extreme environments during evolution such as freshwater habitats. The amphidromous teleost fish, Galaxias maculatus is found mainly migrating between estuaries and rivers, but some landlocked populations have been described in lakes formed during the last deglaciation process in the Andes. In the present st...

The influence of culture density on growth, stress system and metabolism has been assessed in A. regius juveniles submitted to different initial stocking densities (3, 7, 10 and 13 g L-1) for 40 days. On days 0, 12, 27 and 40 of the experiment, biometric parameters were measured. In addition, plasma, liver and muscle samples were taken for biochemi...

Senegalese sole (Solea senegalensis, Kaup 1858) is a commercially important teleost fish. The osmoregulatory system of this species has been previously characterized, especially at branchial and renal levels; however, the osmoregulatory role of the digestive tract has not been studied so far. In this study we assessed the modifications induced in t...

In this study we assessed the influence of three different environmental salinities (5, 15 and 31 psu during 90 days) on growth, osmoregulation, energy metabolism and digestive capacity in juveniles of the Notothenioid fish Eleginops maclovinus. At the end of experimental time samples of plasma, liver, gill, intestine, kidney, skeletal muscle, stom...

The aim of this study was to evaluate the inclusion of two macroalgae as dietary ingredients on growth, body composition, intermediate metabolism, intestinal enzymes and gut histology of Sparus aurata juveniles. Six isocaloric and isonitrogenous diets incorporating 5%, 15% or 25% of Gracilaria cornea or Ulva rigida meal were tested against a contro...

The effects of starvation and re-feeding on metabolites and tissue composition, GH/IGF-I axis, and digestive enzyme activities in juvenile thick-lipped grey mullet (Chelon labrosus) were evaluated. Fish were divided into three feeding groups (n = 72, 82.00 ± 4.09 g initial body mass). The control group was fed 1% of their body mass once a day throu...

In this study, the protective effects of diphenyl diselenide [(PhSe)2] on quinclorac- induced toxicity were investigated in silver catfish (Rhamdia quelen). The fish were fed for 60 days with a diet in the absence or in the presence of 3.0 mg/Kg (PhSe)2. Animals were further exposed to 1 mg/L quinclorac for 8 days. At the end of experimental period...

This study investigated the effects of prolonged exposure of silver catfish (Rhamdia quelen) to the essential oil (EO) of Hesperozygis ringens. Ventilatory rate (VR), stress and metabolic indicators, energy enzyme activities, and mRNA expression of adenohypophyseal hormones were examined in specimens that were exposed for 6 h to 0 (control), 30 or...

The aim of this study was to determine the impact of diets with different plant protein ingredients on proximate composition, tissue metabolites and tissue fatty acid composition, as well as hepatic and intestinal histological modifications in Senegalese sole (Solea senegalensis). Fish (21.5 ± 2.8 g body weight) were fed six isonitrogenous and isoe...

The aim of this study was to evaluate immunological, metabolic and osmoregulatory secondary stress responses in Eleginops maclovinus specimens submitted to three different stocking densities: i) low (3.1 kg m−3), medium (15 kg m−3) and high (60 kg m−3) during 10 days, alone or in combination with a previous treatment of a protein extract of the pat...

Gill is a crucial osmoregulatory organ for the acclimation of teleosts to different environmental salinities. Ionic exchange in this tissue is carried on by several pumps, channels and transporters, with special relevance on the Na+/K+- and the H+-ATPase. These ATPases have been described to be affected by changes in the thyroid and interrenal syst...

Under a stress situation, the hypothalamic-pituitary-interrenal (HPI) axis is stimulated releasing as end product cortisol to blood, being its synthesis and release controlled at different levels. Hypothalamic corticotropin releasing hormone (CRH) stimulates ACTH synthesis and release from adenohypophyseal corticotropic cells, and this hormone indu...

Metabolic modifications associated with natural environmental conditions were assessed in the meagre Argyrosomus regius cultured in earthen ponds under natural photoperiod and temperature. Juvenile specimens (90-100 g initial weight) were sampled (plasma, liver and muscle) every two months for 18 months (between December 2004 and May 2006). Specime...

In this work, we have assessed the effects of different stocking densities on the biometry, survival and physiological status of the wedge sole (Dicologoglossa cuneata), focusing on changes in the stress system and intermediate metabolism, with the aim of determining a stress indicator for chronic-stress situations in this species. Wedge sole were...

The aim of this study was to carry out a comparative analysis of the osmoregulatory properties and associated energy metabolism of euryhaline flatfish species that are cultured in the world. Culture of flatfish (pleuronectiformes) requires stage- and species-dependent osmotic conditions for rearing. Additionally, geographic origin of broodstock ani...

The final products of the hypothalamus-pituitary-thyroid and hypothalamus-pituitary-interrenal axes affect energy metabolism in teleost fish. The purpose of this study was to determine the effects of both hormonal systems on hepatic intermediary metabolism in gilthead sea bream juveniles (Sparus aurata). The following compounds were administered fo...

Thyroid and interrenal systems are implied in energy metabolism. Both endocrine pathways produce hormones (T3 and cortisol, respectively) which are considered hyperglycemic, unless their effects in fish are still not clear. The aim of this study was to elucidate the relationships of these two systems with the intermediary metabolism of the gilthead...

It now is widely recognised that the global temperature is rising, a phenomenon which could alter the effects of pollution on wildlife. In order to assess the role of temperature and exposure to chlorine due to cooling water discharges, a battery of metabolic, oxidative stress and histological parameters were evaluated in Mytilus galloprovincialis...

Los productos finales del eje hipotálamo-hipofisario-tiroideo y del eje hipotálamo-hipófisis-interrenal afectan al metabolismo energético de los peces teleósteos. El objetivo de este estudio ha sido conocer los efectos sobre el metabolismo intermediario hepático de ambos sistemas hormonales en la dorada (Sparus aurata). Para ello se administraron d...

El objetivo de este estudio ha sido conocer los efectos del sistema tiroideo y del sistema interrenal sobre el metabolismo intermediario la dorada (Sparus aurata L.). Para ello se administraron oralmente durante 35 días, las siguientes sustancias: i) 3,5,3’-triyodotironina (T3), hormona tiroidea biológicamente activa; ii) propiltiouracilo, fármaco...

In this work, the effects of the stocking density on the physiological stress and biometric features of the brill were studied. No differences for survival rate, feeding efficiency, Conversion Index and feeding intake were not detected among the treatments. The growth rate showed an inverse lineal relationship with stocking density, and there were...

The mobilization of nutrients and sexual hormone changes during the reproductive cycle of the Mediterranean mussel (Mytilus galloprovincialis), aswell as sex related differences have been assessed using adults brought from the field. Metabolites (glucose and glycogen) and lipid composition were determined in themantle and digestive gland. Moreover,...

The physiological responses of Senegalese sole to a sudden salinity change were investigated. The fish were first acclimated to an initial salinity of 37.5 ppt for 4 h. Then, one group was subjected to increased salinity (55 ppt) while another group was subjected to decreased salinity (5 ppt). The third group (control group) remained at 37.5 ppt. W...

n the present study, the influence of high stocking density and food deprivation on red porgy (Pagrus pagrus L.) energy metabolism was investigated after 14 and 21 days assessing plasmatic, hepatic, and muscular parameters. Specimens were submitted to four different experimental conditions: (1) fed fish under low stocking density (4 kg m−3, LSD-F);...

The application of probiotics on aquatic animals is increasing for a better fish welfare status as well as an environment-friendly activity which are actual demands of modern aquaculture industry. A bacterium from skin mucus of healthy gilthead seabream (Sparus aurata L.) has been isolated and identified as Shewanella putrefaciens Pdp11. Different...

Senegalese sole (Solea senegalensis) is a eurytherm teleost that under natural conditions can be exposed to annual water temperature fluctuations between 12 and 26°C. This study assessed the effects of temperature on sole metabolic status, in particular in what concerns plasma free amino acid changes during thermal acclimation. Senegalese sole main...

Physiological responses after an acute handling stress and their subsequent effects on innate immune parameters, plasma free amino acids (AA) and liver energy substrates were assessed in Senegalese sole (Solea senegalensis). Eight groups of six specimens (136.1±58.4 g wet weight) were maintained undisturbed, while other eight groups of six specimen...

The effects of two different environmental salinities [brackish water (BW), 12‰; sea water (SW), 39‰] and initial stock densities [low (LD), 1.0 g L−1; high (HD), 2.0 g L−1] on growth, osmoregulation, stress and energy metabolism of the fry Pagrus pagrus were investigated over a period of 45 days. Pagrus pagrus (n=80, 5.51 ± 0.25 g mean initial bod...

The effects of dietary administration of probiotic Pdp11, a bacterial probiotic strain from the Alteromonadaceae family, on growth and stress tolerance to high stocking density was analyzed in juvenile gilthead sea bream Sparus auratus. In the first trial, juvenile specimens were fed during 116 days with control feed or diets supplemented with Pdp1...

The effects of prolonged feed deprivation were assessed on blood plasma metabolites and free amino acid levels in Solea senegalensis. Juvenile specimens were maintained at two experimental conditions (24 h fasted and 21 days feed-deprived). In feed-deprived fish, relative growth rate and hepatosomatic index as well as plasma triglycerides and prote...

The impact of cadmium on metabolism and osmoregulation was assessed in gilthead sea bream (Sparus aurata). Seawater acclimated fish were injected intraperitoneally with a sublethal dose of cadmium (1.25 mg Cd/kg body wt). After 7 days, half of the injected fish were sampled. The remaining fish were transferred to hypersaline water and sampled 4 day...

We have investigated the regulation of thyroidal status and osmoregulatory capacities in juveniles from the teleost Solea senegalensis acclimated to different ambient temperatures. Juveniles, raised in seawater at 19°C, were acclimated for 3weeks to temperatures of 12, 19 and 26°C. Since our preliminary observations showed that at 12°C feed intake...

The effects of four different concentrations of nitrite (0, 25, 50 and 100 mg/L) on osmoregulation, stress and metabolism of Solea senegalensis were assessed, after a period of 10 days in a time course experiment. Juvenile sole (67.31±0.26 g mean initial body weight) were randomly distributed in eight tanks and supported under four concentrations o...

Osmoregulatory response to abrupt changes in environmental salinities in Senegalese sole (Solea senegalensis) was studied in a time course experiment. Juvenile specimens were submitted to hypoosmotic (salinity from 38 to 5) and hyperosmotic (from 38 to 55) acute transfer and sampled at 1, 3, and 10 days. Plasmatic, branchial and renal osmoregulator...

Seasonal variations in osmoregulatory and metabolic parameters were assessed in juvenile gilthead sea bream (Sparus auratus) cultured in earthen ponds under a natural photoperiod and temperature. Specimens were sampled, and the plasma, gill, kidney and liver were collected during winter 2005 and 2006 (January), spring 2005 (April), summer 2005 (Jul...

The osmoregulatory responses of 20 days of acclimation to environmental salinities of 5‰, 15‰, 25‰, 35‰ and 55‰ were assessed in juveniles of wedge sole (Dicologoglossa cuneata Moreau, 1881). This sole shows a good capacity to adapt to this range of environmental salinities. A direct linear relationship between environmental salinity and plasma osm...

Physiological responses to a high stocking density were tested in juvenile wedge sole Dicologoglossa cuneata (Moreau). Fish were kept at low (1 kg m−2), medium (3 kg m−2) and high (9 kg m−2) stocking densities for 22 days. No differences in the weight, length, survival and hepatosomatic index were observed among treatments. Basal plasma cortisol an...

Previous studies have shown that Senegalese sole is partially euryhaline in the juvenile phase, being able to adapt to a wide range of salinities in a short-time period, due to changes at the osmoregulatory and metabolic level. This study aimed to assess the effects of acclimation of sole to a wide range of salinities, with a special emphasis on th...

The effects of three different environmental salinities (15, 25 and 39‰) on growth, osmoregulation and energy metabolism of juvenile Senegalese sole (Solea senegalensis Kaup, 1858) after a period of 10 weeks were investigated. Immature sole (n = 150, 39 ± 1 g mean initial body weight) were randomly divided in 6 groups of 25 fish and reared under th...

The effects of an acute stress on cellular and humoral non-specific immune functions of Senegalese sole (Solea senegalensis) were assessed. Eight groups of six specimens were used for acute stress challenge (air exposed during 3 minutes), while other eight groups were maintained undisturbed (control). A group was sampled for plasma cortisol and lys...

The effects of an acute stress on cellular and humoral non-specific immune functions of Senegalese sole (Solea senegalensis) were assessed. Eight groups of six specimens were used for acute stress challenge (air exposed during 3 minutes), while other eight groups were maintained undisturbed (control). A group was sampled for plasma cortisol and lys...

The osmoregulatory response of Senegalese sole (Solea senegalensis, Kaup 1858) to 14-day exposure and throughout 17-day exposure to different environmental salinities was investigated. A linear relationship was observed between environmental salinity and gill Na(+),K(+)-ATPase activity whereas kidney Na(+),K(+)-ATPase activity was unaffected. Two o...