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1.
Isotopes Environ Health Stud ; 55(5): 478-498, 2019 Oct.
Article de Anglais | MEDLINE | ID: mdl-31402710

RÉSUMÉ

Faecal isotopic analysis may complement other non-invasive wildlife survey tools for monitoring landscape use by carnivores, such as motion-detecting cameras and non-invasive genetic sampling. We analysed carbon, nitrogen, and strontium isotopes in faecal matter produced by jaguars (Panthera onca) as well as bones from consumed prey at the Mountain Pine Ridge Forest Reserve (MPR) in Belize, Central America. The MPR is ideally suited for a spatial isotope study as vegetation and geology both vary considerably. The isotopic composition of faecal matter should reflect the habitat and geology where consumed prey lived. We used bone from consumed prey recovered from jaguar scats as a proxy for diet. Faecal matter and bone showed comparable spatial isotopic trends, suggesting that the isotopic composition of jaguar faeces can be used to detect foraging in different habitats (pine forest versus broadleaf forest) or on different geologies (Mesozoic carbonates; Palaeozoic granite, contact metamorphics, and metasediments). This result is reassuring as bones are not always present in carnivore scats. Studying landscape use by cryptic and wide-ranging carnivore species like jaguars remains challenging. Isotopic analysis of faecal matter complements the existing array of non-invasive spatial monitoring tools.


Sujet(s)
Isotopes du carbone/analyse , Fèces/composition chimique , Isotopes de l'azote/analyse , Panthera/physiologie , Comportement prédateur , Animaux , Belize , Os et tissu osseux/composition chimique , Carnivorisme/physiologie , Collagène/analyse , Collagène/composition chimique , Écosystème , Isotopes du strontium/analyse
2.
Mar Pollut Bull ; 144: 134-139, 2019 Jul.
Article de Anglais | MEDLINE | ID: mdl-31179979

RÉSUMÉ

The hypothesis that carnivorous consumers associated with the seabed are more likely to ingest marine debris was tested based on stomach content analysis of fish (Trichiurus lepturus and species of Ariidae) and cetaceans (Sotalia guianensis and Pontoporia blainvillei). Among 596 stomach contents, only 22 (3.7%) contained debris. The debris was flexible plastic, nylon yard, paper, latex, styrofoam and cigarette filter. The proportion of stomach contents with debris varied among species: P. blainvillei (pelagic demersal consumer) presented the highest frequency of ingestion (15.7%), while T. lepturus (pelagic consumer), S. guianensis (pelagic consumer) and Ariidae (demersal consumer) presented similar frequencies (1.3-1.8%). Therefore, a feeding site in the water column does not predict the probability of debris ingestion. Concerning these species, this probability seems to be more associated with prey-capture strategies (or feeding behavior), regardless of debris availability in the environment.


Sujet(s)
Carnivorisme , Dauphins/physiologie , Perciformes/physiologie , Matières plastiques/analyse , Eau de mer/composition chimique , Déchets/analyse , Polluants chimiques de l'eau/analyse , Animaux , Brésil , Carnivorisme/physiologie , Consommation alimentaire , Contenus gastro-intestinaux/composition chimique
3.
Plant Biol (Stuttg) ; 20(3): 591-601, 2018 May.
Article de Anglais | MEDLINE | ID: mdl-29266665

RÉSUMÉ

Genlisea violacea is a Brazilian endemic carnivorous plant species distributed in the cerrado biome, mainly in humid environments, on sandy and oligotrophic soil or wet rocks. Studies on reproductive biology or pollination in the Lentibulariaceae are notably scarce; regarding the genus Genlisea, the current study is the first to show systematic and standardised research on reproductive biology from field studies to describe the foraging of visiting insects and determine the effective pollinators of Genlisea. We studied two populations of G. violacea through the observation of flower visitors for 4 months of the rainy and dry seasons. Stigmatic receptivity, pollen viability, and breeding system were evaluated together with histochemistry and morphological analyses of flowers. The flowers showed stigmatic receptivity of 100% in open buds and mature flowers, reducing to 80% for senescent flowers. Nearly 80% of pollen grains are viable, decreasing to 40-45% after 48 h. Nectar is produced by glandular trichomes inside the spur. Two bee species are effective pollinators: one of the genus Lasioglossum (subgenus Dialictus: Halictidae) and the other of the genus Ceratina (subgenus Ceratinula: family Apidae). Moreover, bee-like flies of the Syrphidae family may also be additional pollinators. Genlisea violacea is an allogamous and self-compatible species. The differences in flower-visiting fauna for both populations can be attributed to factors such as climate, anthropogenic effect, seasonal factors related to insects and plants, as well as the morphological variation of flowers in both populations.


Sujet(s)
Lamiales/physiologie , Pollinisation/physiologie , Brésil , Carnivorisme/physiologie , Fleurs/anatomie et histologie , Fleurs/physiologie , Fleurs/ultrastructure , Lamiales/anatomie et histologie , Reproduction/physiologie
4.
PLoS One ; 12(11): e0188386, 2017.
Article de Anglais | MEDLINE | ID: mdl-29161322

RÉSUMÉ

Caribbean seagrass habitats provide food and protection for reef-associated juvenile fish. The invasive seagrass Halophila stipulacea is rapidly altering these seascapes. Since its arrival in the Caribbean in 2002, H. stipulacea has colonized and displaced native seagrasses, but the function of this invasive seagrass as a juvenile fish habitat remains unknown. To compare diversity, community structure, and abundance of juvenile fish between H. stipulacea and native seagrass beds, fish traps were deployed in four nearshore bays around St. Thomas, U.S. Virgin Islands. Traps were deployed in Frenchman, Lindbergh, and Sprat Bays for 24 h intervals in patches of bare sand, patches of H. stipulacea and patches of the native Caribbean seagrasses Thalassia testudinum and Syringodium filiforme. Traps were then deployed in Brewers Bay for 12 h intervals in stands of H. stipulacea and S. filiforme. Relative and total abundances of juvenile fish, identified at least to family, were compared across treatment habitats for each trap deployment period. The catch from H. stipulacea, compared to native seagrasses, comprised a greater abundance of nocturnal carnivores Lutjanus synagris (family Lutjanidae) and Haemulon flavolineatum (family Haemulidae). Additionally, the herbivore species Sparisoma aurofrenatum (family Labridae) and Acanthurus bahianus (family Acanthuridae) and the diurnal carnivore species Pseudopeneus maculatus (family Mullidae) were relatively scarce in H. stipulacea. The catch from sand was much smaller, compared to vegetated habitats, and comprised only L. synagris, H. flavolineatum, and H. aurolineatum. These results provide evidence of reduced family diversity and altered juvenile fish assemblages in H. stipulacea, driven by an abundance of some nocturnal carnivores and scarcity of herbivores and diurnal carnivores. The findings from the present work underpin the need for further investigation and mitigation of this invasion, particularly where H. stipulacea is driving seascape-alterations of key juvenile fish habitats.


Sujet(s)
Écosystème , Poissons/croissance et développement , Plantes tolérantes au sel/croissance et développement , Migration animale/physiologie , Animaux , Caraïbe , Carnivorisme/physiologie , Récifs de corail , Poissons/métabolisme , Herbivorie/physiologie , Espèce introduite , Iles Vierges des États-Unis
5.
PLoS One ; 12(7): e0180484, 2017.
Article de Anglais | MEDLINE | ID: mdl-28723946

RÉSUMÉ

The carnivorous plants of the family Lentibulariaceae have attained recent attention not only because of their interesting lifestyle, but also because of their dynamic nuclear genome size. Lentibulariaceae genomes span an order of magnitude and include species with the smallest genomes in angiosperms, making them a powerful system to study the mechanisms of genome expansion and contraction. However, little is known about mitochondrial DNA (mtDNA) sequences of this family, and the evolutionary forces that shape this organellar genome. Here we report the sequencing and assembly of the complete mtDNA from the endemic terrestrial Brazilian species Utricularia reniformis. The 857,234bp master circle mitochondrial genome encodes 70 transcriptionaly active genes (42 protein-coding, 25 tRNAs and 3 rRNAs), covering up to 7% of the mtDNA. A ltrA-like protein related to splicing and mobility and a LAGLIDADG homing endonuclease have been identified in intronic regions, suggesting particular mechanisms of genome maintenance. RNA-seq analysis identified properties with putative diverse and important roles in genome regulation and evolution: 1) 672kbp (78%) of the mtDNA is covered by full-length reads; 2) most of the 243kbp intergenic regions exhibit transcripts; and 3) at least 69 novel RNA editing sites in the protein-coding genes. Additional genomic features are hypothetical ORFs (48%), chloroplast insertions, including truncated plastid genes that have been lost from the chloroplast DNA (5%), repeats (5%), relics of transposable elements mostly related to LTR retrotransposons (5%), and truncated mitovirus sequences (0.4%). Phylogenetic analysis based on 32 different Lamiales mitochondrial genomes corroborate that Lentibulariaceae is a monophyletic group. In summary, the U. reniformis mtDNA represents the eighth largest plant mtDNA described to date, shedding light on the genomic trends and evolutionary characteristics and phylogenetic history of the family Lentibulariaceae.


Sujet(s)
Carnivorisme/physiologie , Évolution moléculaire , Génome mitochondrial , Génome végétal , Magnoliopsida/génétique , Phylogenèse , ADN intergénique , ADN mitochondrial/génétique , ADN des plantes/génétique , Introns
6.
PLoS One ; 11(7): e0158919, 2016.
Article de Anglais | MEDLINE | ID: mdl-27391425

RÉSUMÉ

Alpha-amylases are ubiquitously distributed throughout microbials, plants and animals. It is widely accepted that omnivorous crustaceans have higher α-amylase activity and number of isoforms than carnivorous, but contradictory results have been obtained in some species, and carnivorous crustaceans have been less studied. In addition, the physiological meaning of α-amylase polymorphism in crustaceans is not well understood. In this work we studied α-amylase in a carnivorous lobster at the gene, transcript, and protein levels. It was showed that α-amylase isoenzyme composition (i.e., phenotype) in lobster determines carbohydrate digestion efficiency. Most frequent α-amylase phenotype has the lowest digestion efficiency, suggesting this is a favoured trait. We revealed that gene and intron loss have occurred in lobster α-amylase, thus lobsters express a single 1830 bp cDNA encoding a highly conserved protein with 513 amino acids. This protein gives rise to two isoenzymes in some individuals by glycosylation but not by limited proteolysis. Only the glycosylated isoenzyme could be purified by chromatography, with biochemical features similar to other animal amylases. High carbohydrate content in diet down-regulates α-amylase gene expression in lobster. However, high α-amylase activity occurs in lobster gastric juice irrespective of diet and was proposed to function as an early sensor of the carbohydrate content of diet to regulate further gene expression. We concluded that gene/isoenzyme simplicity, post-translational modifications and low Km, coupled with a tight regulation of gene expression, have arose during evolution of α-amylase in the carnivorous lobster to control excessive carbohydrate digestion in the presence of an active α-amylase.


Sujet(s)
Protéines d'arthropode , Carnivorisme/physiologie , Régulation de l'expression des gènes codant pour des enzymes/physiologie , Palinuridae , alpha-Amylases , Animaux , Protéines d'arthropode/biosynthèse , Protéines d'arthropode/génétique , ADN complémentaire/génétique , ADN complémentaire/métabolisme , Glycosylation , Isoenzymes/biosynthèse , Isoenzymes/génétique , Palinuridae/génétique , Palinuridae/métabolisme , Protéolyse , alpha-Amylases/biosynthèse , alpha-Amylases/génétique
7.
PLoS One ; 11(5): e0153900, 2016.
Article de Anglais | MEDLINE | ID: mdl-27144980

RÉSUMÉ

A new interaction between insects and carnivorous plants is reported from Brazil. Larvae of the predatory flower fly Toxomerus basalis (Diptera: Syrphidae: Syrphinae) have been found scavenging on the sticky leaves of several carnivorous sundew species (Drosera, Droseraceae) in Minas Gerais and São Paulo states, SE Brazil. This syrphid apparently spends its whole larval stage feeding on prey trapped by Drosera leaves. The nature of this plant-animal relationship is discussed, as well as the Drosera species involved, and locations where T. basalis was observed. 180 years after the discovery of this flower fly species, its biology now has been revealed. This is (1) the first record of kleptoparasitism in the Syrphidae, (2) a new larval feeding mode for this family, and (3) the first report of a dipteran that shows a kleptoparasitic relationship with a carnivorous plant with adhesive flypaper traps. The first descriptions of the third instar larva and puparium of T. basalis based on Scanning Electron Microscope analysis are provided.


Sujet(s)
Carnivorisme/physiologie , Diptera/physiologie , Drosera/physiologie , Fleurs/physiologie , Animaux , Brésil , Aliments , Larve/physiologie , Feuilles de plante/physiologie
8.
Nat Commun ; 7: 11250, 2016 Apr 07.
Article de Anglais | MEDLINE | ID: mdl-27052750

RÉSUMÉ

Diet is commonly assumed to affect the evolution of species, but few studies have directly tested its effect at macroevolutionary scales. Here we use Bayesian models of trait-dependent diversification and a comprehensive dietary database of all birds worldwide to assess speciation and extinction dynamics of avian dietary guilds (carnivores, frugivores, granivores, herbivores, insectivores, nectarivores, omnivores and piscivores). Our results suggest that omnivory is associated with higher extinction rates and lower speciation rates than other guilds, and that overall net diversification is negative. Trait-dependent models, dietary similarity and network analyses show that transitions into omnivory occur at higher rates than into any other guild. We suggest that omnivory acts as macroevolutionary sink, where its ephemeral nature is retrieved through transitions from other guilds rather than from omnivore speciation. We propose that these dynamics result from competition within and among dietary guilds, influenced by the deep-time availability and predictability of food resources.


Sujet(s)
Oiseaux/génétique , Régime alimentaire , Extinction biologique , Chaine alimentaire , Spéciation génétique , Modèles statistiques , Animaux , Oiseaux/classification , Carnivorisme/physiologie , Poissons , Herbivorie/génétique , Insectes , Phylogenèse , Nectar des plantes , Poaceae
9.
PLoS One ; 10(11): e0141651, 2015.
Article de Anglais | MEDLINE | ID: mdl-26524336

RÉSUMÉ

This study evaluated feeding patterns and ontogenetic variations in a non-native fish species (Plagioscion squamosissimus) in an isolated lake in the Upper Paraná River floodplain. Quarterly samplings were performed from April 2005 to February 2006 using plankton nets to capture larvae, seining nets for juveniles, and gill nets and trammel for adults. Stomach contents (n = 378) were examined according to the volumetric method in which the volume of each food item was estimated using graduated test tubes or a glass counting plate. During early development (larval stage), P. squamosissimus consumed mainly Cladocera and Copepoda. Juveniles showed a more diverse diet, including shrimp (Macrobrachium amazonicum), fish, aquatic insects (Trichoptera, Ephemeroptera, Chironomidae and pupae of Diptera) and plants. It was notable the high proportion of cannibalism (23.3%) in this stage. Adults consumed predominantly shrimp and fish. The use of food resources varied significantly between development stages (ANOSIM; r = 0.458; p<0.005), showing changes in food preferences during ontogeny. The Similarity Percentage Analysis (SIMPER) indicated that Cladocera and Copepoda were responsible for the differences observed between the larval stages of pre-flexion, flexion and post-flexion. M. amazonicum and Chironomidae were responsible for the differences between juvenile and larval stages, while M. amazonicum and other fishes caused the differences between adults and other ontogenetic stages. These results are confirmed by the relationship between standard length and developmental periods (ANCOVA; r2 = 0.94; p<0.0001). In general, there were low values of trophic niche breadth. The essentially carnivorous habit from the early stages of P. squamosissimus and the predominant use of M. amazonicum by adults have important roles in feeding patterns of the species, suggesting a major contribution to its success and establishment, especially in lentic environments.


Sujet(s)
Carnivorisme/physiologie , Perciformes/croissance et développement , Animaux , Brésil , Contenus gastro-intestinaux/composition chimique , Espèce introduite , Rivières
10.
Rev. bras. enferm ; Rev. bras. enferm;68(2): 191-197, Mar-Apr/2015. tab
Article de Portugais | LILACS, BDENF - Infirmière | ID: lil-752514

RÉSUMÉ

RESUMO Objetivo: analisar o desenvolvimento e a mobilização de competências relacionais, centrais no processo de cuidar, pelo estudante de enfermagem ao longo do seu processo de formação. Método: estudo descritivo-correlacional de abordagem quantitativa. A amostra foi constituída pelos estudantes do curso de enfermagem de uma Escola Superior de Saúde, no litoral de Portugal e os dados foram coletados através do Inventário de Competências Relacionais de Ajuda, já testado. Resultados: os estudantes adquirem gradualmente as competências genéricas, competências de comunicação e competências de contacto, atingindo a média mais alta no último ano do curso, enquanto na subescala competências empáticas os estudantes do 2º ano apresentam um valor médio superior. Conclusão: a idade e o ano do curso são variáveis decisivas na aquisição de competências específicas (empáticas e comunicação) pelos estudantes de enfermagem. .


RESUMEN Objetivo: este estudio analiza el desarrollo y la movilización de expertos relacional, central en la atención al estudiante de enfermería a lo largo de su processo formación. Método: se realizó un estudio descriptivo-correlacional de enfoque cuantitativo. La muestra incluyó a los alumnos del curso de enfermería de la Escuela de Salud, en la costa de Portugal y los datos fueron recogidos a través del Inventario de Habilidades Relational Ayuda, ya probado. Resultados: los resultados obtenidos indican que los estudantes adquirir gradualmente “habilidades blandas”, “habilidades de comunicación” y “habilidades de contacto”, alcanzando el promedio más alto en el último año, mientras que en subescala de “habilidades empáticas” estudiantes de segundo año tienen un valor promedio más alto. Conclusión: la edad y el año del curso son variables determinantes en la adquisición de habilidades específicas (Empática y la comunicación) de los estudiantes de enfermería. .


ABSTRACT Objective: to analyze the development and mobilization of relational skills central to the caring process among nursing students throughout their professional training. Method: this was a quantitative study, descriptive and cross-sectional in design. The sample consisted of nursing undergraduate students from the Higher School of Health Sciences, in the city of Évora, Portugal. Data were collected using the previously validated Helping Relational Skills Inventory. Results: the students gradually acquired “generic skills”, “communication skills” and “contact skills”, presenting the highest mean score in the last year of the program. However, the highest mean score for the “empathetic skills” subscale was presented by second-year students. Conclusion: age and year in program were found to be decisive variables regarding the acquisition of specifi c skills (empathetic and communication) by nursing students. .


Sujet(s)
Humains , Animaux , Agriculture/méthodes , Arthropodes/classification , Chaine alimentaire , Prairie , Modèles statistiques , Arthropodes/physiologie , Biodiversité , Biomasse , Carnivorisme/physiologie , Allemagne , Herbivorie/physiologie , Poaceae/physiologie
11.
J Comp Physiol B ; 185(2): 225-41, 2015 Feb.
Article de Anglais | MEDLINE | ID: mdl-25528145

RÉSUMÉ

Three closely related characids, Tambaqui (omnivore), black Piranha (carnivore), and Pacu (herbivore), all Serrasalmidae, inhabit the ion-poor, acidic Rio Negro. We compared O2-consumption and N excretion rates in vivo, and sodium, chloride, glucose, and ammonia transport characteristics of gut sac preparations in vitro. The Pacu had a significantly higher weight-specific oxygen consumption, and a lower N/Q ratio than the omnivorous Tambaqui, and a significantly lower urea-N excretion rate than the carnivorous black Piranha, suggesting N-limitation in the herbivorous Pacu. With a value of 2.62 ± 0.15, gut to fork length ratio in the Pacu was about 2.5 times higher than in the black Piranha, and 2.0 times higher than in the Tambaqui. Anterior intestinal activities of three enzymes involved in N-fixation for amino acid synthesis (glutamate dehydrogenase, glutamate-oxaloacetate transferase, and glutamate-pyruvate transferase) were generally greatest in the carnivore and lowest in the herbivore species. In all three species, sodium, chloride, glucose, and ammonia were taken up at high rates from the intestine, resulting in an isosmotic fluid flux. Comparing the area-specific fluid flux of the anterior, mid, and posterior gut sections, no difference was detected between the three sections of the Pacu, while in the Tambaqui, it was highest in the anterior section, and in the black Piranha highest in the middle section. Overall, the area-specific uptake rates for sodium, chloride, glucose, and ammonia of anterior, mid, and posterior sections were similar in all three species, indicating that there is no difference in the area-specific transport rates associated with trophic position. The net ammonia uptake flux from gut interior was not significantly different from the net ammonia efflux to the serosal fluid, so that the ammonia removed from the intestine by the mucosal epithelium was quantitatively transferred through the tissue to the serosal side in all three species. Thus, metabolic activity of gut tissue did not significantly influence the net ammonia transfer. Due to the much higher gut to fork length ratio, the overall transport capacity of the gut of the herbivorous Pacu by far exceeded the transport capacity of their carnivorous and omnivorous relatives, thus compensating for the lower digestibility and the low Na(+), Cl(-), and N-content of the plant diet. Accordingly, in order to cope with the more difficult digestible plant material and the very low nitrogen content of plants, herbivorous fish have not evolved more effective area-specific transport capacities, but rather have increased the length of the gut.


Sujet(s)
Carnivorisme/physiologie , Poissons/métabolisme , Herbivorie/physiologie , Muqueuse intestinale/métabolisme , Ammoniac/métabolisme , Animaux , Transport biologique , Brésil , Chlorures/métabolisme , Poissons/classification , Ions/métabolisme , Azote/métabolisme , Oxygène/métabolisme , Sodium/métabolisme
12.
Ecotoxicol Environ Saf ; 97: 17-25, 2013 Nov.
Article de Anglais | MEDLINE | ID: mdl-23921221

RÉSUMÉ

We evaluated the levels of selenium and mercury in five fish species commonly eaten by local populations of the Brazilian Amazon. Fish specimens were sampled in two lotic and three lentic areas at two different phases of the hydrological cycle. Analyses of Carbon and Nitrogen stable isotopes allowed us to confirm the trophic levels of the fish species (one herbivorous, two omnivorous and two piscivorous) and verify that these levels remained unchanged with the habitats and the season. The levels of selenium and mercury in fish varied from 50ng/g to 1006ng/g and from 17ng/g to 3502ng/g respectively. For both seasons, fish from lotic ecosystems presented higher selenium concentrations. An inverse pattern was observed between selenium and mercury concentrations within the trophic chain, and this in both seasons. Indeed, the highest mean concentrations of selenium and lowest mean concentrations of mercury were measured in the herbivorous species and the opposite in the piscivorous species. Our results unequivocally demonstrate that local riverside populations will maximize the selenium health benefits of eating fish while minimizing their risk of being chronically exposed to mercury by preferentially consuming herbivorous species and to some extent omnivorous species, while avoiding piscivorous species.


Sujet(s)
Carnivorisme/physiologie , Poissons/physiologie , Herbivorie/physiologie , Mercure/analyse , Rivières , Sélénium/analyse , Polluants chimiques de l'eau/analyse , Animaux , Brésil , Isotopes du carbone/analyse , Poissons/métabolisme , Chaine alimentaire , Mercure/métabolisme , Isotopes de l'azote/analyse , Saisons , Sélénium/métabolisme , Polluants chimiques de l'eau/métabolisme
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