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1.
Commun Biol ; 4(1): 863, 2021 07 15.
Artigo em Inglês | MEDLINE | ID: mdl-34267313

RESUMO

Organisms comprise multiple interacting parts, but few quantitative studies have analysed multi-element systems, limiting understanding of phenotypic evolution. We investigate how disparity of vertebral morphology varies along the axial column of mammalian carnivores - a chain of 27 subunits - and the extent to which morphological variation have been structured by evolutionary constraints and locomotory adaptation. We find that lumbars and posterior thoracics exhibit high individual disparity but low serial differentiation. They are pervasively recruited into locomotory functions and exhibit relaxed evolutionary constraint. More anterior vertebrae also show signals of locomotory adaptation, but nevertheless have low individual disparity and constrained patterns of evolution, characterised by low-dimensional shape changes. Our findings demonstrate the importance of the thoracolumbar region as an innovation enabling evolutionary versatility of mammalian locomotion. Moreover, they underscore the complexity of phenotypic macroevolution of multi-element systems and that the strength of ecomorphological signal does not have a predictable influence on macroevolutionary outcomes.


Assuntos
Adaptação Fisiológica/fisiologia , Evolução Biológica , Carnivoridade/fisiologia , Locomoção/fisiologia , Mamíferos/fisiologia , Coluna Vertebral/fisiologia , Análise de Variância , Animais , Atividade Motora/fisiologia , Coluna Vertebral/anatomia & histologia , Coluna Vertebral/diagnóstico por imagem , Fatores de Tempo , Tomografia Computadorizada por Raios X , Microtomografia por Raio-X
2.
Commun Biol ; 4(1): 547, 2021 05 13.
Artigo em Inglês | MEDLINE | ID: mdl-33986452

RESUMO

Birds are characterized by evolutionary specializations of both locomotion (e.g., flapping flight) and digestive system (toothless, crop, and gizzard), while the potential selection pressures responsible for these evolutionary specializations remain unclear. Here we used a recently developed molecular phyloecological method to reconstruct the diets of the ancestral archosaur and of the common ancestor of living birds (CALB). Our results suggest a trophic shift from carnivory to herbivory (fruit, seed, and/or nut eater) at the archosaur-to-bird transition. The evolutionary shift of the CALB to herbivory may have essentially made them become a low-level consumer and, consequently, subject to relatively high predation risk from potential predators such as gliding non-avian maniraptorans, from which birds descended. Under the relatively high predation pressure, ancestral birds with gliding capability may have then evolved not only flapping flight as a possible anti-predator strategy against gliding predatory non-avian maniraptorans but also the specialized digestive system as an evolutionary tradeoff of maximizing foraging efficiency and minimizing predation risk. Our results suggest that the powered flight and specialized digestive system of birds may have evolved as a result of their tropic shift-associated predation pressure.


Assuntos
Aves , Carnivoridade/fisiologia , Herbivoria/fisiologia , Animais , Evolução Biológica , Dieta , Dinossauros/anatomia & histologia , Ecologia/métodos , Ecossistema , Evolução Molecular , Filogenia , Comportamento Predatório
3.
Nat Commun ; 12(1): 2453, 2021 04 27.
Artigo em Inglês | MEDLINE | ID: mdl-33907186

RESUMO

Parasitoid wasps inflict widespread death upon the insect world. Hundreds of thousands of parasitoid wasp species kill a vast range of insect species. Insects have evolved defensive responses to the threat of wasps, some cellular and some behavioral. Here we find an unexpected response of adult Drosophila to the presence of certain parasitoid wasps: accelerated mating behavior. Flies exposed to certain wasp species begin mating more quickly. The effect is mediated via changes in the behavior of the female fly and depends on visual perception. The sight of wasps induces the dramatic upregulation in the fly nervous system of a gene that encodes a 41-amino acid micropeptide. Mutational analysis reveals that the gene is essential to the behavioral response of the fly. Our work provides a foundation for further exploration of how the activation of visual circuits by the sight of a wasp alters both sexual behavior and gene expression.


Assuntos
Proteínas de Drosophila/genética , Drosophila melanogaster/genética , Drosophila simulans/genética , Drosophila/genética , Receptores Ionotrópicos de Glutamato/genética , Receptores Odorantes/genética , Comportamento Sexual Animal/fisiologia , Vespas/patogenicidade , Adaptação Fisiológica , Animais , Animais Geneticamente Modificados , Carnivoridade/fisiologia , Drosophila/metabolismo , Drosophila/parasitologia , Proteínas de Drosophila/deficiência , Proteínas de Drosophila/metabolismo , Drosophila melanogaster/metabolismo , Drosophila melanogaster/parasitologia , Drosophila simulans/metabolismo , Drosophila simulans/parasitologia , Feminino , Fertilidade/genética , Regulação da Expressão Gênica , Masculino , Neurônios/citologia , Neurônios/metabolismo , Reconhecimento Visual de Modelos/fisiologia , Receptores Ionotrópicos de Glutamato/deficiência , Receptores Odorantes/deficiência , Vespas/fisiologia , beta-Caroteno 15,15'-Mono-Oxigenase/genética , beta-Caroteno 15,15'-Mono-Oxigenase/metabolismo
4.
Proc Natl Acad Sci U S A ; 117(52): 33325-33333, 2020 12 29.
Artigo em Inglês | MEDLINE | ID: mdl-33288693

RESUMO

Human-wildlife conflicts occur worldwide. Although many nonlethal mitigation solutions are available, they rarely use the behavioral ecology of the conflict species to derive effective and long-lasting solutions. Here, we use a long-term study with 106 GPS-collared free-ranging cheetahs (Acinonyx jubatus) to demonstrate how new insights into the socio-spatial organization of this species provide the key for such a solution. GPS-collared territory holders marked and defended communication hubs (CHs) in the core area of their territories. The CHs/territories were distributed in a regular pattern across the landscape such that they were not contiguous with each other but separated by a surrounding matrix. They were kept in this way by successive territory holders, thus maintaining this overdispersed distribution. The CHs were also visited by nonterritorial cheetah males and females for information exchange, thus forming hotspots of cheetah activity and presence. We hypothesized that the CHs pose an increased predation risk to young calves for cattle farmers in Namibia. In an experimental approach, farmers shifted cattle herds away from the CHs during the calving season. This drastically reduced their calf losses by cheetahs because cheetahs did not follow the herds but instead preyed on naturally occurring local wildlife prey in the CHs. This implies that in the cheetah system, there are "problem areas," the CHs, rather than "problem individuals." The incorporation of the behavioral ecology of conflict species opens promising areas to search for solutions in other conflict species with nonhomogenous space use.


Assuntos
Acinonyx/fisiologia , Comunicação Animal , Carnivoridade/fisiologia , Animais , Feminino , Geografia , Humanos , Masculino , Namíbia
5.
Evolution ; 74(12): 2681-2702, 2020 12.
Artigo em Inglês | MEDLINE | ID: mdl-33085081

RESUMO

The skeleton is a complex arrangement of anatomical structures that covary to various degrees depending on both intrinsic and extrinsic factors. Among the Feliformia, many species are characterized by predator lifestyles providing a unique opportunity to investigate the impact of highly specialized hypercarnivorous diet on phenotypic integration and shape diversity. To do so, we compared the shape of the skull, mandible, humerus, and femur of species in relation to their feeding strategies (hypercarnivorous vs. generalist species) and prey preference (predators of small vs. large prey) using three-dimensional geometric morphometric techniques. Our results highlight different degrees of morphological integration in the Feliformia depending on the functional implication of the anatomical structure, with an overall higher covariation of structures in hypercarnivorous species. The skull and the forelimb are not integrated in generalist species, whereas they are integrated in hypercarnivores. These results can potentially be explained by the different feeding strategies of these species. Contrary to our expectations, hypercarnivores display a higher disparity for the skull than generalist species. This is probably due to the fact that a specialization toward high-meat diet could be achieved through various phenotypes. Finally, humeri and femora display shape variations depending on relative prey size preference. Large species feeding on large prey tend to have robust long bones due to higher biomechanical constraints.


Assuntos
Adaptação Biológica , Evolução Biológica , Carnivoridade/fisiologia , Feliformes/anatomia & histologia , Fenótipo , Esqueleto/anatomia & histologia , Animais , Dieta
6.
Curr Opin Endocrinol Diabetes Obes ; 27(5): 312-316, 2020 10.
Artigo em Inglês | MEDLINE | ID: mdl-32833688

RESUMO

PURPOSE OF REVIEW: The aim of this study was to summarize current contributions affecting knowledge and predictions about the nutritional adequacy of plant-free diets, contextualized by historical accounts. RECENT FINDINGS: As demonstrated in recent experiments, nutrient interactions and metabolic effects of ketogenic diets can impact nutritional needs, sometimes resulting in nutrient-sparing effects. Other studies highlight conflicting hypotheses about the expected effect on metabolic acidosis, and therefore mineral status, of adding alkaline mineral-rich vegetables. SUMMARY: A carnivore diet is a newly popular, but as yet sparsely studied form of ketogenic diet in which plant foods are eliminated such that all, or almost all, nutrition derives from animal sourced foods. Ketogenic diets are already nutritionally controversial due to their near-complete absence of carbohydrate and high dietary fat content, but most ketogenic diet advocates emphasize the inclusion of plant foods. In this review, we discuss the implications of relying solely on animal sourced foods in terms of essential nutrient status.


Assuntos
Carnivoridade/fisiologia , Dieta , Nutrientes/administração & dosagem , Animais , Dieta Cetogênica , Humanos , Nutrientes/metabolismo , Estado Nutricional , Proteínas de Vegetais Comestíveis/administração & dosagem , Plantas Comestíveis/fisiologia
7.
Genetica ; 148(2): 87-99, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32096054

RESUMO

Crabs feed on a wide range of items and display diverse feeding strategies. The primary objective of this study was to investigate 10 digestive enzyme genes in representative crabs to provide insights into the genetic basis of feeding habits among crab functional groups. Crabs were classified into three groups based on their feeding habits: herbivores (HV), omnivores (OV), and carnivores (CV). To test whether crabs' feeding adaptations matched adaptive evolution of digestive enzyme genes, we examined the 10 digestive enzyme genes of 12 crab species based on hepatopancreas transcriptome data. Each of the digestive enzyme genes was compared to orthologous sequences using both nucleotide- (i.e., PAML and Datamonkey) and protein-level (i.e., TreeSAAP) approaches. Positive selection genes were detected in HV crabs (AMYA, APN, and MGAM) and CV crabs (APN, CPB, PNLIP, RISC, TRY, and XPD). Additionally, a series of positive selection sites were localized in important functional regions of these digestive enzyme genes. This is the first study to characterize the molecular basis of crabs' digestive enzyme genes based on functional feeding group. Our data suggest that HV crabs have evolved an enhanced digestion capacity for carbohydrates, and CV crabs have acquired digestion capacity for proteins and lipids.


Assuntos
Braquiúros/genética , Evolução Molecular , Trato Gastrointestinal/enzimologia , Seleção Genética/genética , Adaptação Fisiológica/genética , Animais , Braquiúros/classificação , Braquiúros/enzimologia , Carnivoridade/classificação , Carnivoridade/fisiologia , Dieta , Herbivoria/classificação , Herbivoria/genética
8.
PLoS Biol ; 17(10): e3000427, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31600203

RESUMO

Leaves display a remarkable range of forms, from flat sheets with simple outlines to cup-shaped traps. Although much progress has been made in understanding the mechanisms of planar leaf development, it is unclear whether similar or distinctive mechanisms underlie shape transformations during development of more complex curved forms. Here, we use 3D imaging and cellular and clonal analysis, combined with computational modelling, to analyse the development of cup-shaped traps of the carnivorous plant Utricularia gibba. We show that the transformation from a near-spherical form at early developmental stages to an oblate spheroid with a straightened ventral midline in the mature form can be accounted for by spatial variations in rates and orientations of growth. Different hypotheses regarding spatiotemporal control predict distinct patterns of cell shape and size, which were tested experimentally by quantifying cellular and clonal anisotropy. We propose that orientations of growth are specified by a proximodistal polarity field, similar to that hypothesised to account for Arabidopsis leaf development, except that in Utricularia, the field propagates through a highly curved tissue sheet. Independent evidence for the polarity field is provided by the orientation of glandular hairs on the inner surface of the trap. Taken together, our results show that morphogenesis of complex 3D leaf shapes can be accounted for by similar mechanisms to those for planar leaves, suggesting that simple modulations of a common growth framework underlie the shaping of a diverse range of morphologies.


Assuntos
Carnivoridade/fisiologia , Lamiales/citologia , Células Vegetais/ultraestrutura , Desenvolvimento Vegetal/fisiologia , Folhas de Planta/citologia , Polaridade Celular , Proliferação de Células , Forma Celular , Tamanho Celular , Lamiales/crescimento & desenvolvimento , Folhas de Planta/crescimento & desenvolvimento
9.
Sci Rep ; 9(1): 15344, 2019 10 25.
Artigo em Inglês | MEDLINE | ID: mdl-31653949

RESUMO

Although sexual size dimorphism (SSD) is widespread across the animal tree of life, the underlying evolutionary processes that influence this phenomenon remains elusive and difficult to tease apart. In this study, I examined how social system (as a proxy for sexual selection) and diet (as a proxy for natural selection) influenced the evolution of SSD in terrestrial carnivorans (Carnivora; Mammalia). Using phylogenetic comparative methods, I found that are territorial solitary and carnivorous carnivorans exhibited selection towards increased degree of male-biased SSD compared to other carnivorans with alternative social systems and diets. I also found the absence of Rensch's rule across most carnivoran clades, suggestion a relaxation of the influences of sexual selection on SSD. These results together suggest that sexual selection and niche divergence together are important processes influencing the evolution of male-biased SSD in extant terrestrial carnivorans.


Assuntos
Tamanho Corporal , Carnivoridade/fisiologia , Caracteres Sexuais , Animais , Peso Corporal , Dieta , Feminino , Masculino , Modelos Biológicos , Filogenia
10.
Isotopes Environ Health Stud ; 55(5): 478-498, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31402710

RESUMO

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.


Assuntos
Isótopos de Carbono/análise , Fezes/química , Isótopos de Nitrogênio/análise , Panthera/fisiologia , Comportamento Predatório , Animais , Belize , Osso e Ossos/química , Carnivoridade/fisiologia , Colágeno/análise , Colágeno/química , Ecossistema , Isótopos de Estrôncio/análise
11.
Sci Rep ; 9(1): 11199, 2019 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-31371768

RESUMO

The long-chain (≥C20) polyunsaturated fatty acid biosynthesis capacity of fish varies among species, with trophic level hypothesised as a major factor. The biosynthesis capacity is largely dependent upon the presence of functionally diversified fatty acyl desaturase 2 (Fads2) enzymes, since many teleosts have lost the gene encoding a Δ5 desaturase (Fads1). The present study aimed to characterise Fads2 from four teleosts occupying different trophic levels, namely Sarpa salpa, Chelon labrosus, Pegusa lascaris and Atherina presbyter, which were selected based on available data on functions of Fads2 from closely related species. Therefore, we had insight into the variability of Fads2 within the same phylogenetic group. Our results showed that Fads2 from S. salpa and C. labrosus were both Δ6 desaturases with further Δ8 activity while P. lascaris and A. presbyter Fads2 showed Δ4 activity. Fads2 activities of herbivorous S. salpa are consistent with those reported for carnivorous Sparidae species. The results suggested that trophic level might not directly drive diversification of teleost Fads2 as initially hypothesised, and other factors such as the species' phylogeny appeared to be more influential. In agreement, Fads2 activities from P. lascaris and A. presbyter were similar to their corresponding phylogenetic counterparts Solea senegalensis and Chirostoma estor.


Assuntos
Ácidos Graxos Dessaturases/metabolismo , Ácidos Graxos Insaturados/biossíntese , Proteínas de Peixes/metabolismo , Peixes/fisiologia , Sequência de Aminoácidos/genética , Animais , Carnivoridade/fisiologia , Ensaios Enzimáticos , Ácidos Graxos Dessaturases/química , Ácidos Graxos Dessaturases/genética , Ácidos Graxos Insaturados/química , Proteínas de Peixes/química , Proteínas de Peixes/genética , Herbivoria/fisiologia , Filogenia , Alinhamento de Sequência , Especificidade da Espécie , Especificidade por Substrato/fisiologia
12.
Mar Pollut Bull ; 144: 134-139, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31179979

RESUMO

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.


Assuntos
Carnivoridade , Golfinhos/fisiologia , Perciformes/fisiologia , Plásticos/análise , Água do Mar/química , Resíduos/análise , Poluentes Químicos da Água/análise , Animais , Brasil , Carnivoridade/fisiologia , Ingestão de Alimentos , Conteúdo Gastrointestinal/química
13.
Commun Biol ; 2: 168, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31069277

RESUMO

Spatial planning increasingly incorporates theoretical predictions that artificial habitats assist species movement at or beyond range edges, yet evidence for this is uncommon. We conducted surveys of highly mobile fauna (fishes) on artificial habitats (reefs) on the southeastern USA continental shelf to test whether, in comparison to natural reefs, artificial reefs enhance local abundance and biomass of fishes at their poleward range margins. Here, we show that while temperate fishes were more abundant on natural reefs, tropical, and subtropical fishes exhibited higher abundances and biomasses on deep (25-35 m) artificial reefs. Further analyses reveal that this effect depended on feeding guilds because planktivorous and piscivorous but not herbivorous fishes were more abundant on artificial reefs. This is potentially due to heightened prey availability on and structural complexity of artificial reefs. Our findings demonstrate that artificial habitats can facilitate highly mobile species at range edges and suggest these habitats assist poleward species movement.


Assuntos
Adaptação Fisiológica , Migração Animal/fisiologia , Carnivoridade/fisiologia , Materiais de Construção , Recifes de Corais , Peixes/fisiologia , Animais , Oceano Atlântico , Biodiversidade , Biomassa , Ecossistema , Peixes/classificação , Cadeia Alimentar , Herbivoria/fisiologia , Plâncton/fisiologia , Sudeste dos Estados Unidos , Clima Tropical
14.
New Phytol ; 223(3): 1607-1620, 2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-31087371

RESUMO

(E)-ß-Farnesene (EßF) is the predominant constituent of the alarm pheromone of most aphid pest species. Moreover, natural enemies of aphids use EßF to locate their aphid prey. Some plant species emit EßF, potentially as a defense against aphids, but field demonstrations are lacking. Here, we present field and laboratory studies of flower defense showing that ladybird beetles are predominantly attracted to young stage-2 pyrethrum flowers that emitted the highest and purest levels of EßF. By contrast, aphids were repelled by EßF emitted by S2 pyrethrum flowers. Although peach aphids can adapt to pyrethrum plants in the laboratory, aphids were not recorded in the field. Pyrethrum's (E)-ß-farnesene synthase (EbFS) gene is strongly expressed in inner cortex tissue surrounding the vascular system of the aphid-preferred flower receptacle and peduncle, leading to elongated cells filled with EßF. Aphids that probe these tissues during settlement encounter and ingest plant EßF, as evidenced by the release in honeydew. These EßF concentrations in honeydew induce aphid alarm responses, suggesting an extra layer of this defense. Collectively, our data elucidate a defensive mimicry in pyrethrum flowers: the developmentally regulated and tissue-specific EßF accumulation and emission both prevents attack by aphids and recruits aphid predators as bodyguards.


Assuntos
Afídeos/fisiologia , Carnivoridade/fisiologia , Chrysanthemum cinerariifolium/fisiologia , Flores/fisiologia , Herbivoria , Feromônios/farmacologia , Animais , Monoterpenos Bicíclicos/metabolismo , Chrysanthemum cinerariifolium/efeitos dos fármacos , Chrysanthemum cinerariifolium/genética , Besouros/fisiologia , Flores/efeitos dos fármacos , Regulação da Expressão Gênica de Plantas , Pirofosfatases/genética , Pirofosfatases/metabolismo , Sesquiterpenos/metabolismo , Compostos Orgânicos Voláteis/análise
15.
Sci Rep ; 9(1): 6384, 2019 04 23.
Artigo em Inglês | MEDLINE | ID: mdl-31011158

RESUMO

The gastrointestinal microbiota plays a critical role on host health and metabolism. This is particularly important in teleost nutrition, because fish do not possess some of the necessary enzymes to cope with the dietary challenges of aquaculture production. A main difficulty within fish nutrition is its dependence on fish meal, an unsustainable commodity and a source of organic pollutants. The most obvious sustainable alternatives to fish meal are plant feedstuffs, but their nutritive value is limited by the presence of high levels of non-starch polysaccharides (NSP), which are not metabolized by fish. The composition of fish-gut microbial communities have been demonstrated to adapt when the host is fed different ingredients. Thus, we hypothesized that a selective pressure of plant-based diets on fish gut microbiota, could be a beneficial strategy for an enrichment of bacteria with a secretome able to mobilize dietary NSP. By targeting bacterial sporulating isolates with diverse carbohydrase activities from the gut of European sea bass, we have obtained isolates with high probiotic potential. By inferring the adaptive fitness to the fish gut and the amenability to industrial processing, we identified the best two candidates to become industrially valuable probiotics. This potential was confirmed in vivo, since one of the select isolates lead to a better growth and feed utilization efficiency in fish fed probiotic-supplemented plant-based diets, thus contributing for sustainable and more cost-effective aquaculture practices.


Assuntos
Ração Animal , Bass/microbiologia , Carboidratos/química , Carnivoridade/fisiologia , Microbioma Gastrointestinal , Plantas , Probióticos/isolamento & purificação , Animais , Aquicultura , Biodiversidade , Sobrevivência Celular , Dieta
16.
Sci Rep ; 9(1): 4243, 2019 03 12.
Artigo em Inglês | MEDLINE | ID: mdl-30862868

RESUMO

Avian ceca, a pair of blind sacs arising from the junction of the ileum and colon, are homologous to the cecum in mammals. Cecal size is hypothesized to depend on dietary proclivities and pressures, with faunivorous species having short ceca, whereas herbivorous species have long ceca. Previous tests of this hypothesis, however, did not account for phylogenetic pseudoreplication among closely related taxa. We collated published data on cecal length, dietary category, flying ability, and body mass from 155 avian taxa. Character states were mapped onto a phylogenetic framework, and the permutation tail probability test was used to detect phylogenetic signal in each character. Phylogenetic signal is significant among the characters. As with the cecoappendicular complex in mammals, closely-related birds tend to have similar cecal length. To account for phylogenetic pseudoreplication, we performed phylogenetic generalized least squares regression on cecal length and body mass with dietary category, superordinal-level clade, and flying ability as cofactors. The best-fitting regression model supports the dietary hypothesis for the avian cecum. Among sampled birds of comparable body mass, mean cecal length is significantly longer in herbivorous species than in carnivorous ones (p = 0.008), presumably allowing the extraction of nutrients without the burden of fermenting bulky masses of dietary fiber. Exceptions to this trend, however, suggest that avian ceca are functionally complex and may have additional roles in water balance and nitrogen recycling.


Assuntos
Aves/fisiologia , Ceco/anatomia & histologia , Herbivoria/fisiologia , Filogenia , Especificidade da Espécie , Animais , Aves/anatomia & histologia , Carnivoridade/fisiologia , Ceco/fisiologia , Fibras na Dieta/metabolismo , Fermentação/fisiologia , Voo Animal/fisiologia , Nitrogênio/metabolismo , Nutrientes/metabolismo , Tamanho do Órgão , Equilíbrio Hidroeletrolítico/fisiologia
17.
Proc Natl Acad Sci U S A ; 116(8): 3036-3041, 2019 02 19.
Artigo em Inglês | MEDLINE | ID: mdl-30718421

RESUMO

The repeated evolution of dietary specialization represents a hallmark of mammalian ecology. To detect genomic changes that are associated with dietary adaptations, we performed a systematic screen for convergent gene losses associated with an obligate herbivorous or carnivorous diet in 31 placental mammals. For herbivores, our screen discovered the repeated loss of the triglyceride lipase inhibitor PNLIPRP1, suggesting enhanced triglyceride digestion efficiency. Furthermore, several herbivores lost the pancreatic exocytosis factor SYCN, providing an explanation for continuous pancreatic zymogen secretion in these species. For carnivores, we discovered the repeated loss of the hormone-receptor pair INSL5-RXFP4 that regulates appetite and glucose homeostasis, which likely relates to irregular feeding patterns and constant gluconeogenesis. Furthermore, reflecting the reduced need to metabolize plant-derived xenobiotics, several carnivores lost the xenobiotic receptors NR1I3 and NR1I2 Finally, the carnivore-associated loss of the gastrointestinal host defense gene NOX1 could be related to a reduced gut microbiome diversity. By revealing convergent gene losses associated with differences in dietary composition, feeding patterns, and gut microbiomes, our study contributes to understanding how similar dietary specializations evolved repeatedly in mammals.


Assuntos
Carnivoridade/fisiologia , Trato Gastrointestinal/microbiologia , Herbivoria/genética , Filogenia , Animais , Dieta , Feminino , Microbioma Gastrointestinal/genética , Trato Gastrointestinal/metabolismo , Genoma/genética , Herbivoria/fisiologia , Mamíferos/microbiologia , Plantas , Gravidez , RNA Ribossômico 16S/genética
18.
PLoS One ; 14(1): e0206747, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30640963

RESUMO

New data are reported from analyses of stomach contents from 114 long-finned pilot whales mass-stranded at four locations around Tasmania, Australia from 1992-2006. Identifiable prey remains were recovered from 84 (74%) individuals, with 30 (26%) individuals (17 females and 13 males) having empty stomachs. Prey remains comprised 966 identifiable lower beaks and 1244 upper beaks, belonging to 17 families (26 species) of cephalopods. Ommastrephidae spp. were the most important cephalopod prey accounting for 16.9% by number and 45.6% by reconstructed mass. Lycoteuthis lorigera was the next most important, followed by Ancistrocheirus lesueurii. Multivariate statistics identified significant differences in diet among the four stranding locations. Long-finned pilot whales foraging off Southern Australia appear to be targeting a diverse assemblage of prey (≥10 species dominated by cephalopods). This is compared to other similar studies from New Zealand and some locations in the Northern Hemisphere, where the diet has been reported to be primarily restricted to ≤3 species dominated by cephalopods. This study emphasises the importance of cephalopods as primary prey for Southern long-finned pilot whales and other marine vertebrates, and has increased our understanding of long-finned pilot whale diet in Southern Ocean waters.


Assuntos
Cefalópodes , Conteúdo Gastrointestinal , Baleias Piloto/fisiologia , Animais , Carnivoridade/fisiologia , Conservação dos Recursos Naturais , Feminino , Cadeia Alimentar , Masculino , Estômago , Tasmânia
19.
Sci Rep ; 8(1): 17806, 2018 12 13.
Artigo em Inglês | MEDLINE | ID: mdl-30546026

RESUMO

Turbinal bones are key components of the mammalian rostrum that contribute to three critical functions: (1) homeothermy, (2) water conservation and (3) olfaction. With over 700 extant species, murine rodents (Murinae) are the most species-rich mammalian subfamily, with most of that diversity residing in the Indo-Australian Archipelago. Their evolutionary history includes several cases of putative, but untested ecomorphological convergence, especially with traits related to diet. Among the most spectacular rodent ecomorphs are the vermivores which independently evolved in several island systems. We used 3D CT-scans (N = 87) of murine turbinal bones to quantify olfactory capacities as well as heat or water conservation adaptations. We obtained similar results from an existing 2D complexity method and two new 3D methodologies that quantify bone complexity. Using comparative phylogenetic methods, we identified a significant convergent signal in the rostral morphology within the highly specialised vermivores. Vermivorous species have significantly larger and more complex olfactory turbinals than do carnivores and omnivores. Increased olfactory capacities may be a major adaptive feature facilitating rats' capacity to prey on elusive earthworms. The narrow snout that characterises vermivores exhibits significantly reduced respiratory turbinals, which may reduce their heat and water conservation capacities.


Assuntos
Evolução Biológica , Carnivoridade/fisiologia , Murinae , Cavidade Nasal , Bulbo Olfatório , Animais , Austrália , Murinae/anatomia & histologia , Murinae/fisiologia , Cavidade Nasal/anatomia & histologia , Cavidade Nasal/fisiologia , Bulbo Olfatório/anatomia & histologia , Bulbo Olfatório/fisiologia
20.
PLoS One ; 13(12): e0206310, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30517109

RESUMO

Visual attractiveness and rarity often results in large carnivores being adopted as flagship species for stimulating conservation awareness. Their hunting behaviour and prey selection can affect the population dynamics of their prey, which in turn affects the population dynamics of these large carnivores. Therefore, our understanding of their trophic ecology and foraging strategies is important for predicting their population dynamics and consequently for developing effective conservation programs. Here we concentrate on an endangered species of carnivores, the snow leopard, in the Himalayas. Most previous studies on snow leopard diet lack information on prey availability and/or did not genetically check, whether the identification of snow leopard scats is correct, as their scats are similar to those of other carnivores. We studied the prey of snow leopard in three Himalayan regions in Nepal (Sagarmatha National Park (SNP), Lower Mustang (LM) and Upper Manang (UM) in the Annapurna Conservation Area, during winter and summer in 2014-2016. We collected 268 scats along 139.3 km linear transects, of which 122 were genetically confirmed to belong to snow leopard. Their diet was identified by comparing hairs in scats with our reference collection of the hairs of potential prey. We determined prey availability using 32-48 camera-traps and 4,567 trap nights. In the SNP, the most frequent prey in snow leopard faeces was the Himalayan tahr in both winter and summer. In LM and UM, its main prey was blue sheep in winter, but yak and goat in summer. In terms of relative biomass consumed, yak was the main prey everywhere in both seasons. Snow leopard preferred large prey and avoided small prey in summer but not in winter, with regional differences. It preferred domestic to wild prey only in winter, and in SNP. Unlike most other studies carried out in the same area, our study uses genetic methods for identifying the source of the scat. Studies solely based on visual identification of samples may be strongly biased. Diet studies based on frequency of occurrence of prey tend to overestimate the importance of small prey, which may be consumed more often, but contribute less energy than large prey. However, even assessments based on prey biomass are unlikely to be accurate as we do not know whether the actual size of the prey consumed corresponds to the average size used to calculate the biomass eaten. For example, large adults may be too difficult to catch and therefore mostly young animals are consumed, whose weight is much lower. We show that snow leopard consumes a diverse range of prey, which varies both regionally and seasonally. We conclude that in order to conserve snow leopards it is also necessary to conserve its main wild species of prey, which will reduce the incidence of losses of livestock.


Assuntos
Carnivoridade/fisiologia , Felidae/fisiologia , Animais , Feminino , Masculino , Nepal
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