Pedro L Castro

Universidad de Las Palmas de Gran Canaria | ULPGC · Research Group of Aquaculture

The nutritional profile of aquaculture feeds can be altered with substitution of fish-based ingredients, including the vitamin contents, ultimately affecting the vitamin supply to fish. Requirements for several vitamins have been described for early life stages of species including some as salmonids and carps, but optimum levels for gilthead seabre...

Hydroxyproline (L-Hyp) is amply present in fishmeal but limited in plant-protein sources. This study was conducted to evaluate the effects of supplementation with dietary L-Hyp on the distribution of collagen types in the muscle, and on the texture, survival rate, growth rate, feed utilization, body composition as well as the expression of the gene...

This study describes the histomorphology and immunohistochemical profile of 9 cases of feline piloleiomyosarcoma. Cats ranged in age from 7 to 16 years (mean 10), and tumors were 7 to 24 mm in diameter (mean 15). Tumors were composed of fusiform cells that were haphazardly arranged or in variably sized interwoven bundles. Neoplastic cells had eosin...

The behavioural responses of fish to a stressful situation must be considered an adverse reaction caused by the perception of pain. Consequently, the handling prior to stunning and the immediacy of loss consciousness following stunning are the aspects to take into account during the slaughtering process. The most common commercial stunning method i...

Modern aquaculture feeds tend to contain lower levels of fish based ingredients, while increasing the content of plant ingredients. However, this may alter the vitamin profile of the feeds, leading to unbalanced vitamin supply. Requirements for several vitamins have been established for species such as carps and salmonids, but adequate levels for g...

Mycoplasma pneumoniae (Mp) is a leading cause of human community-acquired pneumonia. To investigate the pathogenesis of the infection, 36 gerbils were intranasally inoculated with Mp culture (30 animals) or sterile mycoplasma broth (6 animals) and euthanized from 1 to 5 weeks post infection. A morphological and immunohistochemical study was carried...

The present work investigated how the combination of poultry oil with microalgae oils, rich in eicosapentaenoic acid and docosahexaenoic acid (ED diets) or n-6 docosapentaenoic acid and n-3 docosahexaenoic acid (DD diets) modulates hepatic lipid metabolism in gilthead sea bream juveniles. Diets were tested using two different fishmeal contents (15%...

Abstract In previous studies, combined inclusion of Zn, Mn and Se in early weaning diets improved larval growth, but suggested a potential toxicity by one of these elements. The present study aimed to determine the effect of the single inclusion of Zn, Mn, Se or Cu, their combination (Control+) or their absence (Control−) on larval diets. At the en...

Substitution of marine ingredients (FM‐FO) by plant protein and oil sources can modify selenium (Se) levels in feeds. Se plays an important role in the antioxidative defence by forming part of selenoproteins. Se requirements of gilthead sea bream are not accurately determined; therefore, this study was conducted to define Se supplementation levels...

Fish meal is increasingly substituted in diets for gilthead sea bream with ingredients of terrestrial origin which may affect the mineral content and availability. Among these minerals, copper (Cu) is an essential trace element whose excess may have a potential toxic effect. Since ingredients of terrestrial origin have higher Cu levels than marine...

Meagre (Argyrosomus regius) is a promising new aquaculture species, however with some bottlenecks to high-scale commercial production. One of those constraints are the scarce information about its nutritional requirements, which difficult the production of optimized diets and can lead to pathological alterations in liver, such as hepatic steatosis....

To describe the effect and the distribution of zinc in different tissues of a representative marine fish species, gilthead seabreams (Sparus aurata Linnaeus, 1758) were fed different diets containing zinc in different sources (organic, inorganic, encapsulated, blood‐rich diet or fishmeal). The effect was monitored by histology in the lens, liver an...

Background: Cytokeratins with epitopes in common with those of alpha (acidic and basic) mammalian keratins have been immunohistochemically demonstrated in the epidermis of reptiles. However, there are no reports of immunohistochemical staining patterns of alpha-keratins in other tissues from reptiles. Because the epithelial tumours usually retain...

Resumen Introducción La microscopia virtual se ha convertido en un recurso educativo alternativo para la enseñanza de la organización estructural de células, tejidos y órganos. Su uso mediante el acceso a páginas web de distintas instituciones actúa como refuerzo y sirve como material adicional combinado con el uso de la microscopia óptica convenc...

There is a need to find sustainable alternatives to fishmeal (FM) and fish oil (FO) in feed formulations to support the continued growth of aquaculture. FM is mostly produced from mass‐caught pelagic species, but the production has been relatively constant for several decades. The aim of this study was to investigate the potential of dietary krill...

Meagre (Argyrosomus regius) is a promising new aquaculture species, with great potential due to its high growth rate, feed efficiency and easy adaptation to captivity. Essential fatty acids (EFA) are required to sustain growth, development, immune status and survival (Watanabe, 1982; Izquierdo, 2005). EFA requirement of meagre fingerlings were prev...

To determine differences between commercial size wild and farmed blackspot seabream, some parameters affecting quality were evaluated during shelf life, namely the fatty acid profiles, pH, muscle colour and Quality Index Method (QIM). In addition, a histological study of the lipids' distribution in the myotome (slow or fast twitch) in different dor...

Yellow-bellied slider turtles (Trachemys scripta scripta) are increasingly being used as animal models for experimental purposes. The aim of this work was to generate some seasonal haematological information for captive yellow-bellied slider turtles as a useful and complementary tool for research trials. Blood samples from 30 healthy adult yellow-b...

The increasing prevalence of yellow-bellied sliders (Trachemys scripta scripta) as pets in the European Union and also its utilization as animal models for experimental purposes makes crucial an accurate classification of their blood cells. The aim of this work was to provide a morphologic classification based on the cytochemical characteristics of...

To describe the distribution of zinc in the retina of a representative marine fish species and to determine whether the intracellular deposition amount correlates with the presentation of the zinc included in the practical diets (organic, inorganic, encapsulated, fish meal and Control diet), we examined the precise localization of endogenous zinc i...

A 7-year-old, male cocker spaniel was presented with a gingival proliferative lesion in the rostral maxilla and enlargement of the regional lymph node. Morphological and immunohistochemical analysis revealed a collision tumour composed of two malignant populations, epithelial and melanocytic, with metastasis of the neoplastic melanocytes to the reg...

In order to determine the differences between wild and farmed blackspot seabream, a promising finfish species for aquaculture, some parameters affecting quality were evaluated, such as proximal and fatty acid profiles, texture, skin and muscle colours and muscle cellularity, along with an extensive sensory assessment. Proximal composition showed a...

Background: The classification of blood cells from the Yellow-Bellied Slider Turtle (Trachemys scripta scripta) is relevant due to their increasing importance as pets and as object of study in clinical settings and research projects. However, no previous ultrastructural characterization of blood cells from turtles of the genus Trachemys has been r...

The concept of nutritional programming raises the interesting possibility of directing specific metabolic pathways or functions in juvenile fish, for example, to improve the use of substitutes to fishmeal and oil, and hence to promote sustainability in aquaculture. The aim of the study was to determine effects of early nutritional stimuli of gilthe...

To gain further insight into the pathogenesis of Mycoplasma bovis-associated pneumonia, cytokine expression in different pulmonary compartments was examined. The expression of tumour necrosis factor (TNF)-α, interleukin (IL)-4 and interferon (IFN)-γ was examined immunohistochemically in the lung of 10 calves infected experimentally with M. bovis. M...

Contents Cytokines, primarily produced by macrophages and lymphocytes, mobilize the immune system in response to infection, particularly at mucosal surfaces. Knowledge of the pathogenesis and persistence of Mycoplasma agalactiae ( Ma ) in the mammary gland is still insufficient. The aim of this study was to elucidate the role of cytokines in the pa...

Dietary lipid source in aquaculture has become a central topic in research whilst natural resources availability diminishes. Hence, to weigh up and forecast consumers impressions, the impact of partial (70%) and complete (100%) dietary replacement of fish oil (FO) by linseed oil (LO) on sensory and quality attributes was studied during the edible s...

Total volatile base nitrogen (TVBN) is a widely used fish spoilage indicator. Because TVBN is typically measured from muscle extracts, analytical laboratories would benefit from understanding how different conditions for storing extracts affect TVBN results. To examine this question, extracts from the muscle of gilthead sea bream (Sparus aurata) we...

Impact on proximate and fatty acids patterns of partial and complete dietary replacement of fish oil (FO) by linseed oil (LO) within on-growing period was evaluated on marketable-size gilthead sea bream (Sparus aurata) during 17 days of ice storage. The practical diets were factorially designed as follows: 100% FO (FO), 70% LO + 30% LO (70LO) and 1...

The post mortem degradation processes that take places in fish muscle gradually modify the initial state of freshness. Tissue degradation is accompanied by drastic myofibrillar proteolysis produced as a consequence of the activation of proteolytic enzymes. In this study, structural changes were correlated with the textural properties of sea bream (...

During a study on shelf life, different parameters were analyzed. For this reason, one group of farm raised European sea bass (Dicentrarchus labrax) from Canary Islands (Spain) sea waters were stored in melting ice for a period of 21 days from the time of harvest. The samples were assessed for their total volatile basic nitrogen contents (TVBN) at...

A study of the lesions of beaked whales (BWs) in a recent mass stranding in the Canary Islands following naval exercises provides a possible explanation of the relationship between anthropogenic, acoustic (sonar) activities and the stranding and death of marine mammals. Fourteen BWs were stranded in the Canary Islands close to the site of an intern...

Arising from: Jepson, P. D. et al. Nature 425, 575–576 (2003); Jepson replies We do not yet know why whales occasionally strand after sonar has been deployed nearby, but such information is important for both naval undersea activities and the protection of marine mammals. Jepson et al. suggest that a peculiar gas-forming disease afflicting some str...

There are spatial and temporal links between some mass strandings of cetaceans - predominantly beaked whales - and the deployment of military sonar. Here we present evidence of acute and chronic tissue damage in stranded cetaceans that results from the formation in vivo of gas bubbles, challenging the view that these mammals do not suffer decompres...

This short communication describes the histological and immunohistochemical characteristics of an unusual variant of squamous cell carcinoma in a dog, in which cells assumed a classic signet-ring appearance. The lesion is compared with other tumours reported in human beings and dogs.

Summary Cutaneous Merkel cells (MCs) have been well documented in humans, but less in other mammals. In dogs, there are only a few references about immunohistochemical characterization of MCs. We present the immunohistochemical profile of MCs in the dog for the most reliable antibodies used in human medicine. Tissue samples from several locations...

In the present work Hafnia alvei was isolated from laying hens displaying a reduction in egg production, loss of appetite, opisthotonus, and death. Multifocal necrotizing hepatitis and splenitis were the most prominent lesions. The organism was identified microbiologically. Laying hens were experimentally inoculated by the oral and intraperitoneal...

An intestinal disease in pigeons (Columba livia) from the Canary Islands characterized by diarrhea and body weight loss is described. Intestinal cryptosporidiosis was identified in three young pigeons. Cryptosporidia were associated with hyperplasia of the intestinal crypts and moderate inflammatory infiltration in lamina propria. This is the first...