Ismael Jerez-Cepa

Universidad de Cádiz | UCA · Department of Biology

Nutritional programming is a promising concept for promoting metabolic adaptation of fish to challenging conditions, such as the increase in water temperature. The present work evaluates in ovo arginine or glutamine supplementation as enhancers of zebrafish metabolic or absorptive capacity, respectively, at optimum (28 ºC) and challenging temperatu...

Acute-stress situations in vertebrates induce a series of physiological responses to cope with the event. While common secondary stress responses include increased catabolism and osmoregulatory imbalances, specific processes depend on the taxa. In this sense, these processes are still largely unknown in ancient vertebrates such as marine elasmobran...

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 assessment of welfare in aquatic animals is currently under debate, especially concerning those kept by humans. The classic concept of animal welfare includes three elements: The emotional state of the organism (including the absence of negative experiences), the possibility of expressing normal behaviors, and the proper functioning of the orga...

The objectives of this work were: 1) develop of molecular stress biomarkers obtaining sequence data of different transcripts, 2) study the molecular stress response through the expression quantification of key gene involved in it, and 3) assess the effects of dietary amino acid additives on stress response in meagre meagres (Argyrososmus regius). F...

The aim of this work was to evaluate the effects of the dietary inclusion of Arthrospira sp. enzyme hydrolysate on gilthead seabream (Sparus aurata) juveniles in a 128-day feeding trial. Algal hydrolysate was tested at low inclusion level, namely, 2 and 4%, against a control diet without Arthrospira sp. supplementation. At the end of the feeding tr...

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...

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...

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.

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...

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...

The use of anesthesia is a common practice in aquaculture to sedate fish and mitigate handling stress. Although the employ of anesthesia is considered beneficial for fish, as it reduces stress and improves welfare, at the same time it may induce hazardous side-effects. The aim of the present study was to investigate the effects of clove oil (CO) an...

The effects of pre-transport handling and addition of essential oil of Myrcia sylvatica (EOMS) during transport on stress pathways activation in Rhamdia quelen were investigated. Fish (n = 400, 25.2 ± 2.9 g) were captured in production ponds and transferred to 100-L tank (density 100 g L− 1). After 24 h, 10 fish were sampled (before transport group...

The effects of diet supplemented with Myrcia sylvatica essential oil (EOMS) on growth and stress tolerance to different stocking densities were assessed in Sparus aurata. Initially, three experimental groups were established: i) control, ii) 1.0 and iii) 2.0 mL EOMS kg dry feed-1. After 90 days, nine fish per group were anesthetized, weighed and sa...

The aim of this work was to evaluate the effect of dietary inclusion of an Arthrospira platensis hydrolysate for feeding Sparus aurata juveniles in a 120-day trial. Microalgae hydrolysate was tested in triplicate at 0% (CONTROL), 2% (SPI-2) and 4% (SPI-4) inclusion level. At the end of the feeding trial, fish body weight was recorded to evaluate gr...

In aquaculture there are stressful situations that can compromise animal welfare. In order to reduce the negative effects of these practices, there is a wide variety of feed additives to improve the quality and general condition of the fish. In this work we assessed the effect of “Relax-fish” additive on the intermediary metabolism of gilthead seab...

In the currently aquaculture industry, it is possible to find plenty of commercial products in order to reduce or mitigate the stress response generated in rearing facilities. In this study we evaluate “Relax-fish” in the response of the sea bass (Dicentrarchus labrax) at two different stress situations: stocking density and transport. Our results...

This study constitutes a first attempt to investigate sex differences in osmoregulatory capacity and metabolic responses in relation to hyper- and hypo-osmoregulation in the intertidal euryhaline crab Uca tangeri . Adult male and female specimens from Cadiz Bay, Spain (36°23′–37′N 6°8′–15′W), were acclimated to three different environmental salinit...

La práctica acuícola requiere el uso de anestésicos de manera deseable y/o imprescindible en múltiples ocasiones, incluso como medio ético para la eutanasia (sobredosis). La elección de un anestésico depende de diversos factores (disponibilidad, coste, facilidad de uso, seguridad del manipulador o naturaleza del trabajo), entre los que destacan su...

La práctica acuícola requiere el uso de anestésicos de manera deseable y/o imprescindible en múltiples ocasiones (situaciones de cirugía, transporte y manipulación), incluso como medio ético para provocar la eutanasia (sobredosis). La elección de un anestésico no depende solo de consideraciones tales como: disponibilidad, coste, facilidad de uso, s...

The use of natural anesthetics in aquaculture has become increasingly important. In this context, the essential oil of Lippia alba (EOLA) is presented as an alternative to traditional methods to mitigate stress in aquaculture. Therefore, the aims of this study were: i) identify the times of anesthesic induction and recovery in juveniles of sea bass...

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...

Aquaculture activities promote stress situations that decrease fish welfare. In this sense, the objective of this study was to evaluate the effects of adding essential oil of Myrcia sylvatica (EOMS), a substance that has been used to mitigate activation of stress system in other teleost, in the diet of gilthead sea bream (Sparus aurata). Juveniles...

Inadequate stocking densities (e.g. high stocking density) activated stress system, affecting the metabolism of lipids, carbohydrates and proteins. The aim of this study was to evaluate the effects of adding essential oil of Myrcia sylvatica (EOMS) in the diet of Sparus aurata juveniles held at different stocking densities. Juvenile specimens were...

Tricaine methanesulfonate (MS-222) is an anesthetic widely used in aquaculture and regulated for use in production in the EU and the USA. In this work were identified: i) the induction and recovery times for meagre juveniles (Argyrosomus regius) using the MS-222 as anesthetic, and ii) the efficacy of this anesthetic under stress conditions by simul...

Meagre (Argyrosomus regius) is a marine teleost that can be found in many coastal environments, from estuarine areas and river mouths to the open sea. Specimens living in natural earthen ponds (“esteros”) modified for aquaculture activity are exposed to environmental fluctuations in salinity or water temperature that affected several physiological...

Fasting prior slaughter is one the most widespread practices used in aquaculture, because the absence of food in the digestive system reduces the enzymatic degradation after rigor mortis. However, there are few studies about the flesh quality and welfare of fish associated to these stressful situations. A chronic stress situation could generate thu...

The endocrine system could be considered as a complex net of pathways for which an interconnection between some of them cannot be ruled out. Cortisol, the main corticosteroid in teleosts, is the final step on the hypothalamic-pituitary-interrenal axis, and its functions are related to intermediary metabolism, osmotic and ionic regulation, growth, s...

Aquaculture practices include several procedures as capture, handling and transport, which cause stress in fish. Anesthetics or sedative substances have been used to reduce this stress. The aim of this study was to evaluate the effects of essential oil of Myrcia sylvatica (EOMS) in the water on stress system activation in the silver catfish Rhamdia...

Under stress conditions, the teleostean hypothalamic-pituitary-interrenal (HPI) axis is stimulated in order to cope with a disturbance of the homeostasis. Endocrine regulation of this axis is controlled at different levels, involving several pathways that activate the synthesis and release of cortisol. This axis starts with the integration of the p...

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...

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...

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...