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1.
J Fish Biol ; 104(4): 1112-1121, 2024 Apr.
Article in English | MEDLINE | ID: mdl-38174622

ABSTRACT

The yellowfin tuna is a very abundant tropical tuna species in the western equatorial Atlantic Ocean and an important fishery resource for the Brazilian tuna fleet. In this study we performed stable isotope analysis to better understand the spatial trophodynamics and dietary changes in yellowfin tuna around two insular marine protected areas in Brazil. A total of 65 yellowfin tuna specimens measuring between 47 and 138 cm LT (total length) were sampled around the archipelagos of Fernando de Noronha (FNA; n = 34) and Saint Peter and Saint Paul (SPSPA; n = 31) between July 2018 and September 2019. Bayesian mixing models and generalized additive models were used to investigate the contributions of four different prey items (zooplankton, cephalopods, fish larvae, and flying fish) to yellowfin tuna diet in each area and their potential changes in relation to predator growth. The four prey items were found to have different overall contributions between the two studied areas, with zooplankton being the most important prey in FNA, whereas flying fish was the most relevant prey to the species' diet in SPSPA. Significant changes in the species diet by size were also found, with fish smaller than 90 cm (TL) having a more generalist diet and larger animals relying more on consuming larger and more nutritious prey (i.e., flying fish). Our results suggest that these two marine protected areas play an important role in ocean dynamics, providing important and different foraging grounds for the development of this predator species.


Subject(s)
Insular Cortex , Tuna , Animals , Bayes Theorem , Atlantic Ocean , Fishes , Feeding Behavior , Pacific Ocean
2.
Sci Total Environ ; 878: 163098, 2023 Jun 20.
Article in English | MEDLINE | ID: mdl-36996984

ABSTRACT

The connection between epipelagic and deep-sea mesopelagic realms controls a variety of ecosystem processes including oceanic carbon storage and the provision of harvestable fish stocks. So far, these two layers have been mostly addressed in isolation and the ways they connect remain poorly understood. Furthermore, both systems are affected by climate change, exploitation of resources, and increasing pervasion of pollutants. Here we use bulk isotopes of δ13C and δ15N of 60 ecosystem components to evaluate the trophic linkage between epipelagic and mesopelagic ecosystems in warm oligotrophic waters. Additionally, we we conducted a comparison of isotopic niche sizes and overlaps across multiple species to evaluate how environmental gradients between epipelagic and mesopelagic ecosystems shape ecological patterns of resource use and competition between species. Our database comprises siphonophores, crustaceans, cephalopods, salpas, fishes, and seabirds. It also includes five zooplankton size classes, two groups of fish larvae, and particulate organic matter collected at different depths. Through this wide taxonomic and trophic variety of epipelagic and mesopelagic species, we show that pelagic species access resources originating from different food sources, mostly autotrophic-based (epipelagics) and microbial heterotrophic-based (mesopelagics). This leads to a sharp trophic dissimilarity between vertical layers. Additionally, we show that trophic specialization increases in deep-sea species and argue that food availability and environmental stability are among the main drivers of this pattern. Finally, we discuss how the ecological traits of pelagic species highlighted in this study can respond to human impacts and increase their vulnerability in the Anthropocene.


Subject(s)
Ecosystem , Fishes , Animals , Humans , Oceans and Seas , Zooplankton , Nutritional Status , Food Chain
3.
Environ Pollut ; 327: 121532, 2023 Jun 15.
Article in English | MEDLINE | ID: mdl-37001599

ABSTRACT

Plastic pollution is present in most marine environments; however, contamination in pelagic predators, including species of economic interest, is still poorly understood. This study aims to access the macro- and microplastic contamination in tuna and large pelagic species and verify whether a trophic transfer occurs from prey to tunas captured by two fleets in the Southwestern Tropical Atlantic (SWTA). We combined different methodological approaches to analyse the intake of macro- and microplastics. In addition to examining the plastics in the fish' stomachs, we investigated the contamination in the prey retrieved from the guts of predators. A low frequency of occurrence (3%) of macroplastic was detected in the tuna and large pelagic species; conversely, we observed a high frequency of microplastic in the tuna's stomachs (100%) and prey analysed (70%). We evinced the trophic transfer of microplastics by analysing the ingestion rate of particles in prey retrieved from the tuna stomachs. In the 34 analysed prey, we detected 355 microplastic particles. The most contaminated prey were cephalopods and fishes of the Bramidae family. The most frequent microplastic shapes in both prey and tuna stomachs were foams, pellets and fibres (<1 mm). A variety of polymers were identified; the most frequent were styrene-butadiene rubber (SBR), polyamide (PA), polyethylene terephthalate (PET) and polyethylene (PE). Our findings enhance scientific knowledge of how the ecological behaviour of marine species can affect microplastic intake.


Subject(s)
Microplastics , Water Pollutants, Chemical , Animals , Plastics , Tuna , Water Pollutants, Chemical/analysis , Environmental Monitoring , Fishes
4.
Sci Rep ; 12(1): 8787, 2022 05 24.
Article in English | MEDLINE | ID: mdl-35610249

ABSTRACT

Tropical marine ecosystems are highly biodiverse and provide resources for small-scale fisheries and tourism. However, precise information on fish spatial distribution is lacking, which limits our ability to reconcile exploitation and conservation. We combined acoustics to video observations to provide a comprehensive description of fish distribution in a typical tropical environment, the Fernando de Noronha Archipelago (FNA) off Northeast Brazil. We identified and classified all acoustic echoes into ten fish assemblage and two triggerfish species. This opened up the possibility to relate the different spatial patterns to a series of environmental factors and the level of protection. We provide the first biomass estimation of the black triggerfish Melichthys niger, a key tropical player. By comparing the effects of euphotic and mesophotic reefs we show that more than the depth, the most important feature is the topography with the shelf-break as the most important hotspot. We also complete the portrait of the island mass effect revealing a clear spatial dissymmetry regarding fish distribution. Indeed, while primary productivity is higher downstream, fish concentrate upstream. The comprehensive fish distribution provided by our approach is directly usable to implement scientific-grounded Marine Spatial Planning.


Subject(s)
Coral Reefs , Ecosystem , Acoustics , Animals , Biodiversity , Fisheries , Fishes
5.
Appl Radiat Isot ; 176: 109862, 2021 Oct.
Article in English | MEDLINE | ID: mdl-34385091

ABSTRACT

Mammography has a crucial role in breast cancer detection. The National Cancer Institute (INCA) estimates that 29.7% of the cancer cases in Brazil are related specifically to the breast. It is necessary to evaluate the mean glandular dose with a new solid-state detector in a digital radiography system, utilizing PMMA phantoms and spacers for different thicknesses. The Selenia Dimensions (Hologic, Bedford) direct radiography (DR) system can perform full-field digital mammographies through digital detectors. This system uses new technologies, such as the digital breast tomosynthesis system (DBT), and employs a sequence of projections acquired over the breast, resulting in images with low contrast. The estimation of breast dose is an important part of mammographic quality control for x-ray mammography. Nevertheless, there are currently no standard protocols for the dosimetry of breast imaging in 3D. Additionally, a x-ray spectra function is crucial to measure a considerable output in x-ray spectrometry. The purpose of this work was to assess the mean glandular dose (MGD) and the spectra in slabs of polymethyl methacrylate (PMMA) and breast equivalent thickness through digital mammography using four experiments: a Hologic Selenia Dimensions mammograph with a solid-state detector; a spectrometer (only for the spectra, in this case); a clinical COMET x-ray tube with a solid-state detector; and the MCNPX code. References recommend that the real environments that work well with digital mammography are in the following tube voltages: 25 kVp; 26 kVp; 28 kVp; 31 kVp and 33 kVp. Taking into account several thicknesses of PMMA, the results of both the MGD in metrological, clinical and simulated cases were in accordance with the references, from 30 mm of PMMA. All the spectra for all cases have indicated good agreement with the references.


Subject(s)
Breast Neoplasms/diagnostic imaging , Mammography/methods , Radiation Dosage , Female , Humans , Phantoms, Imaging
6.
J Fish Biol ; 99(5): 1576-1590, 2021 Nov.
Article in English | MEDLINE | ID: mdl-34302361

ABSTRACT

The objective of this study was to analyse the feeding habits and trophic interactions between four oceanic predatory fish around the Fernando de Noronha Archipelago (FNA), Brazil, in the western equatorial Atlantic (3.86°S/32.42°W), internationally recognized as an environment of high economic and ecological value. For this purpose, biological samples of yellowfin tuna (Thunnus albacares), wahoo (Acanthocybium solandri), barracuda (Sphyraena barracuda) and dolphinfish (Coryphaena hippurus) were collected for stomach content and stable isotope analysis. Values of the index of relative importance revealed varied diets, with a strong presence of teleost fishes (Diodontidae and Exocoetidae) for all species, with yellowfin tuna having a greater diversity of food items. Despite being generalists/opportunists, the feeding strategy of these predators showed a tendency towards a specialized diet in the use of the available resources around the FNA. They presented a narrow trophic niche width (Levin's index, Bi < 0.6) and low overlap between species, except between barracuda and wahoo (MacArthur and Levin's, R0  = 0.72). Isotopic compositions had broad values of δ13 C and δ15 N, and were significantly different between species. Our results provide information about the four species' trophic organization and suggest that the predators avoid competition by preying on different prey, thus allowing their coexistence.


Subject(s)
Fishes , Perciformes , Animals , Brazil , Isotopes , Predatory Behavior
7.
Radiat Prot Dosimetry ; 192(3): 402-412, 2020 Dec 30.
Article in English | MEDLINE | ID: mdl-33320943

ABSTRACT

Digital breast tomosynthesis (DBT) is a screening and diagnostic modality that acquires images of a breast at multiple angles during a short scan. The Selenia Dimensions (Hologic, Bedford, Mass) DBT system can perform both full-field digital mammography and DBT. The system acquires 25 projections over a 15° angular range (from -7.5° to +7.5°). X-ray spectroscopy is generally linked with a high-resolution semiconductor detector through a correction to its energy response function. The energy spectrum describes the radiation field, in which several quality parameters can be extracted, such as the effective energy, half-value layer and exposure. X-ray spectroscopy is usually performed with solid-state semiconductor detectors. Radiation dose is a concern in mammography, as the current protocols recommend that medical physicians evaluate mean glandular dose (MGD) as a part of service quality control. Studies are needed for radiation dose optimization from tomosynthesis patients. The COMET metrological X-ray tube, considered as with a constant potential and cooled, has proved to be a crucial tool in order to obtain the high energy resolution for low-energy radiographs in mammography. The Monte Carlo method, through Monte Carlo N-Particle eXtended (MCNPX), was proven to be an essential tool for image formation and posterior analysis of the deposited dose from breast simulators and radiographic contrast evaluation, for several anode/filter combinations. The purpose of this work was to assess the MGD and spectra in slabs of polymethyl methacrylate (PMMA) and breast equivalent thicknesses using four experiments with a Hologic Selenia Dimensions mammography X-ray tube with multimeter, a spectrometer (only for spectra, in this case), a metrological X-ray tube with a multimeter, and the MCNPX code. References indicate that the real conditions for a mammography X-ray tube that conducts tomosynthesis include tube voltages of 26, 29, 30 and 33 kVp. Taking into account several thicknesses of PMMA, both the MGD and spectral results were in accordance with the references. Most of the spectra were in accordance with the references, showing that the resources used in the experiments can evaluate the energy level received by a patient. The MGD values were lower than those in the references from 30 to 50 mm PMMA, and the data can be used for improvements in the detectors used in the Laboratory of Metrology in the State of Rio de Janeiro University, Brazil. Additionally, in the future, optimization of image quality can be performed for both semiconductors and mammography X-ray equipment.


Subject(s)
Breast , Mammography , Radiographic Image Enhancement , Brazil , Breast/diagnostic imaging , Humans , Monte Carlo Method , Phantoms, Imaging
8.
J Fish Biol ; 95(3): 820-832, 2019 Sep.
Article in English | MEDLINE | ID: mdl-31215642

ABSTRACT

Species-specific disturbance calls of five commercially-important characiform species are described, the Curimatidae commonly called branquinhas: Potamorhina latior, Potamorhina altamazonica and Psectrogaster amazonica; Prochilodontidae: jaraquí Semaprochilodus insignis and curimatã Prochilodus nigricans. All species have a two-chambered swimbladder and the sonic mechanism, present exclusively in males, utilises hypertrophied red muscles between ribs that adhere to the anterior chamber. The number of muscles is unusually plastic across species and varies from 1 to 4 pairs suggesting considerable evolution in an otherwise conservative system. Advertisement calls are produced in river confluences in the Madeira Basin during the high-water mating season (January-February). Disturbance calls and sampling allowed recognition of underwater advertisement choruses from P. latior, S. insignis and P. nigricans. The advertisement calls of the first two species have largely similar characteristics and they mate in partially overlapping areas in the Guaporé River. However, P. latior sounds have a lower dominant frequency and it prefers to call from river confluences whereas S. insignis shoals occur mostly in the main river channel adjacent to the confluence. These results help identify and differentiate underwater sounds and evaluate breeding areas during the courtship of commercially important characids likely to be affected by two hydroelectric dams.


Subject(s)
Animal Communication , Characiformes/physiology , Sexual Behavior, Animal , Acoustics , Air Sacs/anatomy & histology , Air Sacs/physiology , Animals , Characiformes/anatomy & histology , Male , Muscles/anatomy & histology , Muscles/physiology , Reproduction , Rivers , Species Specificity
9.
Vet Parasitol ; 252: 163-166, 2018 Mar 15.
Article in English | MEDLINE | ID: mdl-29559141

ABSTRACT

Ocular thelaziosis is caused by nematodes of the genus Thelazia (Spirurida, Thelaziidae), which inhabit the surface of the eyes and associated tissues. Thelazia callipaeda affects a range of mammal species, including humans, and in the last two decades has been reported in multiple European countries, being classified as an emergent vector-borne pathogen. In Portugal T. callipaeda is endemic in north-eastern areas, where it has been reported in domestic dogs, cats, red foxes (Vulpes vulpes) and wild European rabbits (Oryctolagus cuniculus). We report, for the first time, T. callipaeda in a beech marten (Martes foina) from Portugal and highlight the presence of haplotype 1 as the only one found in Europe, irrespective of the host species and geographical area of provenience.


Subject(s)
Animals, Wild/parasitology , Eye/parasitology , Mustelidae/parasitology , Pets/parasitology , Spirurida Infections/veterinary , Thelazioidea/isolation & purification , Animals , Cat Diseases/epidemiology , Cat Diseases/parasitology , Cats , Dog Diseases/epidemiology , Dog Diseases/parasitology , Dogs , Foxes/parasitology , Portugal/epidemiology , Spirurida Infections/epidemiology , Spirurida Infections/parasitology , Thelazioidea/genetics , Thelazioidea/physiology
10.
Mol Ecol ; 26(10): 2812-2825, 2017 May.
Article in English | MEDLINE | ID: mdl-28222237

ABSTRACT

Social barriers have been shown to reduce gene flow and contribute to genetic structure among populations in species with high cognitive capacity and complex societies, such as cetaceans, apes and humans. In birds, high dispersal capacity is thought to prevent population divergence unless major geographical or habitat barriers induce isolation patterns by dispersal, colonization or adaptation limitation. We report that Iberian populations of the red-billed chough, a social, gregarious corvid with high dispersal capacity, show a striking degree of genetic structure composed of at least 15 distinct genetic units. Monitoring of marked individuals over 30 years revealed that long-distance movements over hundreds of kilometres are common, yet recruitment into breeding populations is infrequent and highly philopatric. Genetic differentiation is weakly related to geographical distance, and habitat types used are overall qualitatively similar among regions and regularly shared by individuals of different populations, so that genetic structure is unlikely to be due solely to isolation by distance or isolation by adaptation. Moreover, most population nuclei showed relatively high levels of genetic diversity, suggesting a limited role for genetic drift in significantly differentiating populations. We propose that social mechanisms may underlie this unprecedented level of genetic structure in birds through a pattern of isolation by social barriers not yet described, which may have driven this remarkable population divergence in the absence of geographical and environmental barriers.


Subject(s)
Genetic Variation , Genetics, Population , Passeriformes/genetics , Social Behavior , Animals , Behavior, Animal , Gene Flow , Genetic Drift , Microsatellite Repeats , Spain
11.
Mitochondrial DNA A DNA Mapp Seq Anal ; 27(3): 2278-81, 2016 05.
Article in English | MEDLINE | ID: mdl-25431821

ABSTRACT

The complete mitochondrial genomes of Red-billed Chough (Pyrrhocorax pyrrhocorax) and Yellow-billed Chough (Pyrrhocorax graculus) were sequenced using the Ion Torrent PGM platform. These mitogenomes contain 16,889 bp (Red-billed Chough) and 16,905 bp (Yellow-billed Chough), including 13 protein-coding genes (PCGs), two ribosomal RNA (rRNA) genes, 22 transfer RNA (tRNA) genes, and a control region (D-loop). The gene content, orientation, and structure are similar to a wide range of other vertebrate species and the nucleotide composition is very similar to other Passeriformes. All PCGs start with ATG, except for COX1 that starts with GTG, and four stop codons and one incomplete stop codon are used (TAA, TAG, AGG, AGA, and T-). The size of PCGs is the same in both mitogenomes, except for ND6 that has one codon less in the Yellow-billed Chough. All the tRNAs can fold into a typical cloverleaf secondary structure. These mitogenomic data can be of great value in complementing forthcoming approaches on molecular ecology, comparative and functional genomics.


Subject(s)
Genome, Mitochondrial , Passeriformes/genetics , Animals , Codon, Initiator , Codon, Terminator , Comparative Genomic Hybridization , DNA, Mitochondrial/chemistry , DNA, Mitochondrial/isolation & purification , DNA, Mitochondrial/metabolism , Electron Transport Complex IV/chemistry , Electron Transport Complex IV/genetics , High-Throughput Nucleotide Sequencing , NADH Dehydrogenase/chemistry , NADH Dehydrogenase/genetics , Open Reading Frames/genetics , RNA, Ribosomal/chemistry , RNA, Ribosomal/isolation & purification , RNA, Ribosomal/metabolism , RNA, Transfer/chemistry , RNA, Transfer/isolation & purification , RNA, Transfer/metabolism , Sequence Analysis, DNA
12.
PLoS One ; 10(10): e0141396, 2015.
Article in English | MEDLINE | ID: mdl-26492091

ABSTRACT

A combination of fisheries dependent and independent data was used to assess the vulnerability of the oceanic whitetip shark to pelagic longline fisheries. The Brazilian tuna longline fleet, operating in the equatorial and southwestern Atlantic, is used as a case study. Fisheries dependent data include information from logbooks (from 1999 to 2011) and on-board observers (2004 to 2010), totaling 65,277 pelagic longline sets. Fisheries independent data were obtained from 8 oceanic whitetip sharks tagged with pop-up satellite archival tags in the area where longline fleet operated. Deployment periods varied from 60 to 178 days between 2010 and 2012. Tagging and pop-up sites were relatively close to each other, although individuals tended to travel long distances before returning to the tagging area. Some degree of site fidelity was observed. High utilization hotspots of tagged sharks fell inside the area under strongest fishing pressure. Despite the small sample size, a positive correlation between tag recorded information and catch data was detected. All sharks exhibited a strong preference for the warm and shallow waters of the mixed layer, spending on average more than 70% of the time above the thermocline and 95% above 120 m. Results indicate that the removal of shallow hooks on longline gear might be an efficient mitigation measure to reduce the bycatch of this pelagic shark species. The work also highlights the potential of tagging experiments to provide essential information for the development of spatio-temporal management measures.


Subject(s)
Conservation of Natural Resources , Ecosystem , Fisheries , Sharks/physiology , Animals , Geography , Population Dynamics
13.
Rev Biol Trop ; 61(3): 1327-39, 2013 Sep.
Article in English | MEDLINE | ID: mdl-24027926

ABSTRACT

The reproduction of Blackfin tuna Thunnus atlanticus has been described for coastal regions, and for a long time, this species was considered to be a strictly continental spawner. Recently, this species was observed around a seamount habitat 500 nautical miles Northeast of Brazil, located between South America and Africa. In this study we describe the reproductive biology of Blackfin tuna at Saint Peter and Saint Paul Archipelago (SPSPA). Male and female gonads were sampled from December 2008 to July 2010, and analyzed macro and microscopically. A total of 361 fish were sampled (247 males and 114 females). Males were more common than females, with a sex ratio of 2.2 male:1 female. The fork length (FL) of all sampled specimens ranged from 38 to 98cm, and larger length classes were more frequent in males. It was possible to distinguish six maturity phases for females: immature, developing, spawning capable, actively spawning, regressing and recovering. Five phases were identified for males: immature, developing, spawning capable, actively spawning and recovering. The gonad index (GI) mean monthly values ranged from 6.6 (SD = 4.1) to 58.4 (SD = 34.7) for females, and from 2.6 (SD = 1.3) to 66.2 (SD = 30.4) for males. For both sexes, the largest GI values were observed at the beginning of the first semester of the year. Size at first maturity was estimated at 48cm FL and 55cm FL for females and males respectively. Approximately 80% of the specimens were adults and considered to be in reproductive conditions. Histological analysis of the ovaries and testes showed that most of the specimens were sexually mature and were reproductively active during all months of the year. However, females with mature ovaries, with large amounts of hydrated oocytes and post-ovulatory follicles, were mainly found from December to March, thus these months may constitute the main spawning season in SPSPA. Batch fecundity varied between 272025 and 1,140584 oocytes for 56 and 68 cm FL females respectively. Oocyte development and spawning patterns suggest a multiple spawning behavior. The results revealed that Blackfin tuna is using the SPSPA as a spawning ground, similar to other species commonly observed in the same area during the same reproductive season.


Subject(s)
Gonads/growth & development , Reproduction/physiology , Sexual Maturation/physiology , Tuna/physiology , Animals , Brazil , Female , Male , Seasons , Sex Ratio , Tuna/classification
14.
Rev. biol. trop ; 61(3): 1327-1339, sep. 2013. ilus, graf, mapas, tab
Article in English | LILACS | ID: lil-688479

ABSTRACT

The reproduction of Blackfin tuna Thunnus atlanticus has been described for coastal regions, and for a long time, this species was considered to be a strictly continental spawner. Recently, this species was observed around a seamount habitat 500 nautical miles Northeast of Brazil, located between South America and Africa. In this study we describe the reproductive biology of Blackfin tuna at Saint Peter and Saint Paul Archipelago (SPSPA). Male and female gonads were sampled from December 2008 to July 2010, and analyzed macro and microscopically. A total of 361 fish were sampled (247 males and 114 females). Males were more common than females, with a sex ratio of 2.2 ♂:1♀. The fork length (FL) of all sampled specimens ranged from 38 to 98cm, and larger length classes were more frequent in males. It was possible to distinguish six maturity phases for females: immature, developing, spawning capable, actively spawning, regressing and recovering. Five phases were identified for males: immature, developing, spawning capable, actively spawning and recovering. The gonad index (GI) mean monthly values ranged from 6.6 (SD=4.1) to 58.4 (SD=34.7) for females, and from 2.6 (SD=1.3) to 66.2 (SD=30.4) for males. For both sexes, the largest GI values were observed at the beginning of the first semester of the year. Size at first maturity was estimated at 48cm FL and 55cm FL for females and males respectively. Approximately 80% of the specimens were adults and considered to be in reproductive conditions. Histological analysis of the ovaries and testes showed that most of the specimens were sexually mature and were reproductively active during all months of the year. However, females with mature ovaries, with large amounts of hydrated oocytes and post-ovulatory follicles, were mainly found from December to March, thus these months may constitute the main spawning season in SPSPA. Batch fecundity varied between 272 025 and 1 140 584 oocytes for 56 and 68cm FL females respectively. Oocyte development and spawning patterns suggest a multiple spawning behavior. The results revealed that Blackfin tuna is using the SPSPA as a spawning ground, similar to other species commonly observed in the same area during the same reproductive season.


A pesar de la importancia de las capturas del atún de aleta negra Thunnus atlanticus en el noreste de Brasil y en las cercanías del Archipiélago San Pedro y San Pablo (ASPSP), hay una escasez de información sobre su reproducción, especialmente en las islas. La reproducción del atún de aleta negra en este archipiélago se estudió de diciembre 2008 a julio 2010. Con este fin, se recolectaron 361 gónadas de hembras y machos, los machos fueron predominantemente más frecuentes en la muestra total, con una proporción sexual de 1♀:2.2 ♂. La longitud furcal todos los ejemplares muestreados varió entre 38 y 98 cm, y los machos fueron más abundantes en las clases de mayor longitud. Los valores medios mensuales del índice gonadal (IG) variaron de 6.6 (SD=4.1) a 58.4 (SD=34.7) y de 2.6 (SD=1.3) a 66.2 (SD=30.4) para hembras y machos, respectivamente. Los mayores valores de IG para ambos sexos fueron observados el inicio del primer semestre. Los análisis histológicos mostraron que la mayoría de los ovarios y testículos correspondieron a especímenes aptos para reproducirse. Sin embargo, hembras con ovarios maduros, con gran cantidad de oócitos hidratados y folículos post ovulatorios, se encontraron principalmente de diciembre a marzo, que se considera es la época de reproducción del atún de aleta negra alrededor del ASPSP.


Subject(s)
Animals , Female , Male , Gonads/growth & development , Reproduction/physiology , Sexual Maturation/physiology , Tuna/physiology , Brazil , Seasons , Sex Ratio , Tuna/classification
15.
Mol Ecol Resour ; 13(3): 473-83, 2013 May.
Article in English | MEDLINE | ID: mdl-23433263

ABSTRACT

High-resolution melting (HRM) analysis is a very attractive and flexible advanced post-PCR method with high sensitivity/specificity for simple, fast and cost-effective genotyping based on the detection of specific melting profiles of PCR products. Next generation real-time PCR systems, along with improved saturating DNA-binding dyes, enable the direct acquisition of HRM data after quantitative PCR. Melting behaviour is particularly influenced by the length, nucleotide sequence and GC content of the amplicons. This method is expanding rapidly in several research areas such as human genetics, reproductive biology, microbiology and ecology/conservation of wild populations. Here we have developed a successful HRM protocol for avian sex identification based on the amplification of sex-specific CHD1 fragments. The melting curve patterns allowed efficient sexual differentiation of 111 samples analysed (plucked feathers, muscle tissues, blood and oral cavity epithelial cells) of 14 bird species. In addition, we sequenced the amplified regions of the CHD1 gene and demonstrated the usefulness of this strategy for the genotype discrimination of various amplicons (CHD1Z and CHD1W), which have small size differences, ranging from 2 bp to 44 bp. The established methodology clearly revealed the advantages (e.g. closed-tube system, high sensitivity and rapidity) of a simple HRM assay for accurate sex differentiation of the species under study. The requirements, strengths and limitations of the method are addressed to provide a simple guide for its application in the field of molecular sexing of birds. The high sensitivity and resolution relative to previous real-time PCR methods makes HRM analysis an excellent approach for improving advanced molecular methods for bird sexing.


Subject(s)
Avian Proteins/chemistry , Birds/genetics , DNA-Binding Proteins/chemistry , Sex Determination Analysis/methods , Transition Temperature , Animals , Avian Proteins/genetics , Base Sequence , DNA Primers/genetics , DNA-Binding Proteins/genetics , Genotype , Molecular Sequence Data , Real-Time Polymerase Chain Reaction , Sensitivity and Specificity , Sequence Analysis, DNA , Species Specificity
16.
Neotrop. ichthyol ; 10(3): 587-592, Sept. 2012. ilus, graf, tab
Article in English | LILACS | ID: lil-653607

ABSTRACT

Reproductive aspects of the Brazilian snapper Lutjanus alexandrei, were characterized, including a description of the development of oocytes and spermatogenic cells, size at first sexual maturity, and fecundity. A total of 540 fish were analyzed with 250 having their gonads sectioned to allow microscopic evaluation. Six maturity stages were identified for females and males: immature, maturing, mature, spawning, spawned, and resting. Fish standard length (SL) varied from 13.0 to 28.3 cm and sex ratio was 1.6 males: 1.0 females. Monthly distributions of mean Gonadosomatic Index (GSI) and maturity stages suggest that spawning occurs mainly in a protracted period, during the warmer months, from November to March. The size of first sexual maturity was estimated at 17.1 cm SL for females and 16.8 cm SL for males. Oocyte development suggests that L. alexandrei exhibits a multiple batch spawning behavior and batch fecundity varied from 34,000 to 324,000 oocytes.


Os aspectos reprodutivos da baúna-de-fogo Lutjanus alexandrei foram caracterizados, incluindo a descrição do desenvolvimento dos ovócitos e células espermatogênicas, do tamanho de primeira maturação sexual, e da fecundidade. Um total de 540 peixes foi analisado, dos quais 250 tiveram as suas gônadas seccionadas para avaliação microscópica. Seis estágios de maturidade sexual foram determinados para fêmeas e machos: imaturo, em maturação, maduro, desovando, desovado e repouso. O comprimento padrão (CP) dos peixes variou de 13,0 a 28,3 cm e a proporção sexual foi de 1,6 machos: 1,0 fêmeas. As distribuições mensais dos valores médios do Índice Gonadosomático (IGS) e dos estágios de maturidade sexual sugerem a ocorrência de desovas em um período prolongado, principalmente nos meses de temperaturas mais quentes, entre novembro e março. O tamanho médio de primeira maturação sexual foi estimado em 17,1 cm CP para as fêmeas e 16,9 cm CP para os machos. O padrão de desenvolvimento dos ovócitos sugere que L. alexandrei exibe comportamento de múltiplas desovas por lote, e a fecundidade variou entre 34.000 a 324.000 ovócitos.


Subject(s)
Animals , Oocytes/growth & development , Perciformes/growth & development , Reproduction/physiology , Semen/physiology , Embryonic Development/genetics
17.
J Wildl Dis ; 44(2): 460-3, 2008 Apr.
Article in English | MEDLINE | ID: mdl-18436680

ABSTRACT

Pulmonary cryptococcosis was observed in a free-living adult female common toad (Bufo bufo) that was killed by a vehicle. Both lungs had various eosinophilic, monomorphic, and spherical to elliptical organisms identified as Cryptoccocus spp. The yeasts were demonstrated by Grocott's silver method and the periodic acid-Schiff reaction and the capsule was positive for mucin with a mucicarmine stain. The agent was confirmed by immunohistochemistry, using the monoclonal antibody anti-Cryptococcus neoformans, and by a polymerase chain reaction-based method using a C. neoformans-specific primer. This report, to the best of our knowledge, represents the first case of cryptococcosis in a common toad.


Subject(s)
Bufo bufo/microbiology , Cryptococcosis/veterinary , Cryptococcus neoformans/isolation & purification , Lung Diseases, Fungal/veterinary , Animals , Cryptococcosis/diagnosis , Female , Immunohistochemistry/veterinary , Lung Diseases, Fungal/diagnosis , Periodic Acid-Schiff Reaction/veterinary , Polymerase Chain Reaction/veterinary , Staining and Labeling/veterinary
18.
Vet Dermatol ; 17(1): 81-4, 2006 Feb.
Article in English | MEDLINE | ID: mdl-16412123

ABSTRACT

This case report describes a highly pruritic, papular and crusted dermatitis affecting the dorsum of a dog and microscopically diagnosed as dermatitis induced by Straelensia cynotis. Histologically, each papule was characterized by a dilated hair follicle with marked pseudoepitheliomatous hyperplasia, perifollicular mucinosis and an abundant mononuclear infiltration by plasma and mast cells. Each dilated follicle contained a larval mite. A therapy including systemic ivermectins and oral antibiotic therapy was initiated, but the clinical response was poor. To the best of the authors' knowledge, this is the first report of straelensiosis in Portugal, and the second in Europe.


Subject(s)
Dermatitis/veterinary , Dog Diseases/diagnosis , Trombiculiasis/veterinary , Trombiculidae , Animals , Dermatitis/diagnosis , Dermatitis/epidemiology , Dermatitis/pathology , Dog Diseases/epidemiology , Dog Diseases/pathology , Dogs , Europe/epidemiology , Immunohistochemistry/veterinary , Male , Portugal/epidemiology , Trombiculiasis/diagnosis , Trombiculiasis/epidemiology , Trombiculiasis/pathology
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