Amalia E. Morales
University of Granada
Network
Latest external collaboration on country level. Dive into details by clicking on the dots.
Publication
Featured researches published by Amalia E. Morales.
Reviews in Fish Biology and Fisheries | 2005
Rosa M. Martínez-Álvarez; Amalia E. Morales; Ana Belen Sanz
Oxygen in its molecular state O2, is essential for many metabolic processes that are vital to aerobic life. Aerobic organisms cannot exist without oxygen, which nevertheless is inherently dangerous to their lives. Like all aerobic organisms, fish are also susceptible to the effects of reactive oxygen and have inherent and effective antioxidant defenses that are well described in the literature. This review investigates the influence of different biotic and abiotic factors (age, phylogenetic position, feeding behavior, environmental factors, oxygen, temperature, presence of xenobiotics) on antioxidant defenses in fish. Studies of antioxidant activity in fish open a number of novel research lines providing greater knowledge of fish physiology, which will benefit various aspects of fish farming and artificial production.
Aquaculture | 1994
Amalia E. Morales; G. Cardenete; M. de la Higuera; A. Sanz
Abstract Most alternative protein sources to fish meal contain other non-protein energy materials which may influence diet utilization. With the objective of making an overall evaluation of the energy utilization of fish feed ingredients, the following diets were studied: two control diets including either fish meal or casein as the sole protein source (FM and CA100, respectively) and three diets where 40% of the fish meal protein was substituted by one of the following sources: cottonseed meal (CO), lupin seed meal (LU) and corn gluten meal (CG). A sixth diet containing casein (CA40), which replaced 40% of the fish meal protein, was also included as an additional control in order to compare the protein ADC calculation using either fish meal protein or casein protein as reference proteins. All diets were made isocaloric (gross energy) and with the same proportion of estimated available macronutrients. Energy flow studies for dietary protein, fat and carbohydrate, together with an evaluation of the digestive utilization of these energy-yielding nutrients and their efficiency for feed conversion and growth showed that dietary energy efficiency was directly related to the digestible energy of the diets which was especially influenced by the dietary carbohydrate source. Fish adjusted their dietary energy intake to digestible energy levels in the diet. Lupin meal carbohydrate digestibility showed very low values compared to the other plant sources. Protein retention efficiency expressed as protein productive value showed values above 40% for all the experimental diets. Energy retention efficiencies as a function of intake, digestible and metabolizable energy are discussed.
Aquaculture | 1994
A. Sanz; Amalia E. Morales; M. de la Higuera; G. Gardenete
Abstract This work evaluated the nutritive potential of sunflower meal protein as compared to soybean meal and fish meal protein in trout diets. Energy utilization was also studied to determine the overall nutritive value of the raw material. Sunflower meal protein could replace up to 40% of fish meal protein in the diet with results very similar to those obtained with soybean protein at the same replacement percentage. Sunflower meal showed good digestive utilization of protein, even though the digestible energy was low due to the carbohydrate fraction. The addition of an appropriate level of digestible carbohydrates to the diet made with this raw material improved the nutritive utilization of the dietary protein and of the diet as a whole.
Comparative Biochemistry and Physiology Part A: Physiology | 1990
Amalia E. Morales; L. García‐Rejón; M. de la Higuera
Abstract 1. 1. The overall effect of handling, anaesthesia and sham injection on some blood metabolites, liver glycogen and several key enzymes involved in liver carbohydrates and nitrogen metabolism was studied in rainbow trout. In addition, the possible role of anaesthesia (MS222) itself as a stress-inductor or suppressor was also studied. 2. 2. Stress resulted in hyperglycaemia and initially in liver glycogen depletion, as well as increasing plasma amino acid levels. 3. 3. Glycogen stores subsequently recovered while amino acid concentration fell. 4. 4. These changes seemed to correlate with the increased activity of liver fructose 1,6-bisphosphatase, glucose 6-phosphate dehydrogenase, alanine aminotransferase and glutamate dehydrogenase, thus supporting the hypothesis that gluconeogenic flux from amino acids increases in stressed trouts. 5. 5. Anaesthesia, under the same experimental conditions, did not seem to mediate in stress production, but rather resulted in stress suppression.
Comparative Biochemistry and Physiology C-toxicology & Pharmacology | 2009
Cristina E. Trenzado; Amalia E. Morales; José M. Palma; Manuel de la Higuera
Rainbow trout maintained at crowding or noncrowding conditions were fed on five experimental diets that were formulated considering two levels of vitamin E (25.6 and 275.6 mg/kg diet), vitamin C (0 and 1000 mg/kg diet) and HUFA (12.5 and 30.5 g/kg diet): -E-HUFA, -E+HUFA, +E-HUFA, +E+HUFA, -C+E+HUFA. Hematological parameters, the activity of some antioxidant enzymes and lipid peroxidation from RBC were evaluated. The SOD isoenzyme pattern was analyzed by nondenaturing PAGE. Hematological response to crowding stress was manifested by increased hemoglobin and RBC count in most of the crowded groups. Antioxidant enzyme activity was clearly affected by dietary HUFA levels, with uncrowded fish fed on +HUFA diets showing a higher SOD activity compared to those fed on -HUFA diets. In uncrowded groups, only one CuZn-SOD isozyme was detected, whereas in the crowded fish a great variability was revealed with up to five isozymes. G6PDH activity was increased in uncrowded -E+HUFA fish compared to the remaining groups. Lipid peroxidation was significantly increased in -E+HUFA fish regardless of fish density. Data supported the negative correlation of lipid peroxidation and hematocrit or hemoglobin explained by decreased erythrocyte stability. Dietary imbalances in vitamin E and HUFA supplementation may promote oxidative stress which triggers hematological deterioration, which in turn would affect the whole hematological status and ultimately fish welfare.
Comparative Biochemistry and Physiology A-molecular & Integrative Physiology | 2008
M. Furné; M. García-Gallego; M. Carmen Hidalgo; Amalia E. Morales; Alberto Domezain; Julio Domezain; Ana Belen Sanz
The digestive enzyme activities were determined in Adriatic sturgeon and rainbow trout during starvation and refeeding period. Overall, the digestive enzyme activities are affected in the same sense in both species. The protease and lipase activities were decreased later than amylase activity. Even after 1 month of starvation, both species would be prepared to digest protein and lipids in an effective way. After 72 days of starvation, the digestive machinery of the sturgeon and of the trout shows an altered capacity to digest macronutrients. The capacity to digest proteins and lipids, after 60 days of refeeding, begins to become re-established in sturgeon and trout. In contrast, in this period, the capacity to digest carbohydrates remains depressed in both species.
Comparative Biochemistry and Physiology A-molecular & Integrative Physiology | 2009
Amalia Pérez-Jiménez; G. Cardenete; Amalia E. Morales; A. García-Alcázar; Emilia Abellán; M. Carmen Hidalgo
Digestive physiology of on-growing common dentex (Dentex dentex), including protease, amylase and lipase activity in stomach, pyloric caeca, anterior and posterior intestine, was evaluated. The influence of dietary macronutrient balance on these digestive processes was also assessed. Four experimental diets with different protein:lipid:carbohydrate ratios (43/16/28; 43/24/4; 38/19/28 and 38/24/13) were formulated. The highest activity for acid proteases was located in the stomach at pH 1.5. Alkaline proteolytic activities showed the highest values in the pyloric caeca and posterior intestine at pH 8.5-9.0. Dentex showed substantial amylase activity in the pyloric caeca and posterior intestine. Lipase activity was higher in the pyloric caeca, anterior and posterior intestine and was not detected in the stomach. Feed composition influenced alkaline protease activity in the anterior and posterior intestine and was higher for the diet with less protein and more carbohydrates. Enhanced amylase activity was observed in the pyloric caeca and posterior intestine in those groups fed on higher carbohydrate and lower lipid level diets. High dietary carbohydrate levels produced the highest lipase activity but this only occurred in the anterior intestine. We can conclude that the digestive tract of dentex adapts well to protein digestion and possesses a high potential for digesting the other dietary macronutrients, too. Dietary carbohydrate content seems to induce changes in protease, amylase and lipase activity.
Aquaculture | 1999
Amalia E. Morales; G. Cardenete; A. Sanz; M. de la Higuera
The validity of crude fibre and acid-insoluble ash as inert markers as alternatives for chromic oxide was tested for digestibility studies in rainbow trout. Six practical diets were assayed: one of fish meal (C), and five in which 40% of the fish meal protein was replaced by corn gluten meal (CGM), cottonseed meal (CSM), lupine seed meal (LSM), soybean meal (SBM) or sunflower meal (SFM) on a crude protein basis. The apparent digestibility coefficients for crude protein, NFE, dry matter and gross energy were calculated using crude fibre, acid-insoluble ash and Cr 2 O 3 as inert markers. For all diets, when acid-insoluble ash was used as the marker, results for the apparent digestibility coefficients for crude protein, NFE, dry matter and gross energy were higher (P < 0.05) than those based on Cr 2 O 3 . All apparent digestibility coefficients for the control, corn gluten meal, cottonseed meal and lupine seed meal diets calculated with crude fibre as the marker were similar to those based on Cr 2 O 3 , whereas all results based on crude fibre for the soybean meal and sunflower meal diets, compared with those obtained with chromic oxide, were lower (P < 0.05). Based on these results, if one considers chromic oxide as the reference marker, then acid-insoluble ash is not a suitable marker for digestibility studies in rainbow trout. With respect to crude fibre, our results suggests that this substance can be an effective endogenous marker, although attention should be paid to the type of crude fibre present in the diets.
Comparative Biochemistry and Physiology A-molecular & Integrative Physiology | 2015
Amalia Pérez-Jiménez; Emilia Abellán; Marta Arizcun; G. Cardenete; Amalia E. Morales; M. Carmen Hidalgo
The present study was aimed to evaluate the capacity of common dentex (Dentex dentex) to efficiently use dietary carbohydrates. So, the effects of different type and levels of carbohydrates on growth performance, feed utilization, fish composition, plasma metabolites and key metabolic pathways in liver and white muscle of common dentex are presented. Nine isonitrogenous (43%) and isoenergetic (22 MJ kg(-1)) diets were formulated combining three types, pregelatinized starch (PS), dextrin (Dx) and maltodextrin (Mx), and three levels (12, 18 and 24%) of carbohydrates. Growth performance was not significantly influenced by treatments. The best feed utilization was observed in 18% Mx group. Higher hepatic lipid content was found in fish fed lower dietary carbohydrate levels. PS induced higher liver and white muscle hexokinase and pyruvate kinase activities compared to the lower values observed for Mx. Malic enzyme and glucose 6-phosphate dehydrogenase in liver and white muscle were lower in Mx group. The influence of dietary carbohydrates source was more noticeable than those induced by the carbohydrate level, when glycolysis and lipogenesis pathways were considered. Common dentex is able to use properly dietary carbohydrates, although optimal dietary inclusion levels are below 24%. The greater protein-sparing effect was promoted by the less complex carbohydrate (maltodextrin) and the best feed utilization indices were obtained at intermediate levels of inclusion (18%).
Archive | 2009
M. García-Gallego; A. Domezain; M. de la Higuera; M.C. Hidalgo; M. Furné; Amalia E. Morales; A. Sanz
Any attempt to save the endangered sturgeon species will depend on the availability of a sufficient stock of the fish in question, as aquaculture is a very suitable tool and has proved feasible for several sturgeon species and, additionally, it could contribute to the development of a new productive activity.