44 registros encontrados - material ARTIGO E unidade Museu de Zoologia
ARTIGO - Inglês
Assunto: Amazônia
Hemigrammus xaveriellus sp. nov. is described from the upper Río Vaupés basin (Amazon basin), Departamento Guaviare, Colombia. It is distinguished...
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Hemigrammus xaveriellus sp. nov. is described from the upper Río Vaupés basin (Amazon basin), Departamento Guaviare, Colombia. It is distinguished from all congeners by the combination of the following characters: presence of a conspicuous, dark, longitudinal midlateral stripe extending along the body; presence of a conspicuous rounded, horizontally elongated humeral blotch anterior to the beginning of the dark midlateral stripe; seven scale rows between the dorsal fin and lateral line (vs. five to six); and five scale rows between the lateral line and pelvic‐fin insertion (vs. three to four). The single mature male of He. xaveriellus possessed a well‐developed urogenital papilla, an unusual feature among characids. The presence of an enlarged urogenital papilla in the family is discussed, and comments regarding the putative relationships of the new species are presented
DOI: https://doi.org/10.1111/jfb.14267
Texto completo: https://onlinelibrary.wiley.com/doi/10.1111/jfb.14267
A new Hyphessobrycon (Characiformes: Characidae) from the Guiana Shield in northern Brazil
ARTIGO - Inglês
Assunto: Brasil
A new species of Hyphessobrycon from a tributary of the Rio Paru do Oeste (Rio Trombetas basin), at the lower Amazon basin draining the Guiana Shield...
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A new species of Hyphessobrycon from a tributary of the Rio Paru do Oeste (Rio Trombetas basin), at the lower Amazon basin draining the Guiana Shield region in Pará State, Brazil, is described. The new species presents a unique combination of an irregularly-shaped humeral blotch, a broad diffuse midlateral stripe, and a roughly triangular caudal peduncle blotch. The new species is herein included in the Hyphessobrycon agulha species-group, and comparisons with species belonging to this group and to a similar-looking non-congener, Hemigrammus bellottii, are presented
ARTIGO - Inglês
Assunto: Peixe
A new species of Pristella is described from the Río Meta drainage, Río Orinoco basin, Colombia. Pristella ariporo, new species, is described as the...
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A new species of Pristella is described from the Río Meta drainage, Río Orinoco basin, Colombia. Pristella ariporo, new species, is described as the second known species of the genus and differs from P. maxillaris by lacking maxillary teeth, possessing all teeth of premaxilla and dentary conical, by the absence of a dark blotch on the pelvic fin and the absence of a humeral blotch. The evaluation of the relationships of the new taxon within Characidae through an extensive phylogenetic analysis recovered Pristella as a monophyletic clade, sister to Bryconella pallidifrons. A new diagnosis of Pristella is provided. Hyphessobrycon axelrodi, the only species of this genus possessing only conical teeth, may actually be a species of Pristella
ARTIGO - Inglês
Assunto: Bagre (Peixe)
Abstract: A new species of the catfish genus Centromochlus (Auchenipteridae, Centromochlinae) is described. The new species is diagnosed by having...
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Abstract: A new species of the catfish genus Centromochlus (Auchenipteridae, Centromochlinae) is described. The new species is diagnosed by having numerous dark rounded blotches over the body and fins, dorsal-fin spine with serrations anteriorly and smooth posteriorly, anal fin of mature males with three unbranched and seven branched rays, anterior nuchal plate absent and posterior nuchal plate not extended ventrally. The new species is described from a small stream in the Estação Ecológica Serra Geral de Tocantins, a natural reserve in the centre of the Brazilian Cerrado, close to the watershed between the Rio Tocantins and the Rio São Francisco basins. The new species is possibly the sister taxon to the recently described Centromochlus meridionalis from the upper Rio Tapajós. Those two species share with Centromochlus perugiae, from the upper Amazon and upper Paraguay, derived features associated with the modified anal fin in sexually mature males
ARTIGO - Inglês
Assunto: Characiformes - Aspectos moleculares
A new species of Characidium is described from headwater tributaries of the upper rio Guaporé, Rio Madeira basin, Mato Grosso state, Brazil. The new...
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A new species of Characidium is described from headwater tributaries of the upper rio Guaporé, Rio Madeira basin, Mato Grosso state, Brazil. The new species can be diagnosed from all congeners, except Characidium summus, for lacking the preorbital and postorbital stripes. It can be diagnosed from the latter species by having 12 circumpeduncular scales (vs. 14), by an adipose fin present (vs. adipose fin absent), and 10–12 bars along the body (vs. absence of bars), among other characters. The new species is so far only known from direct tributaries of the Rio Guaporé at the Serra da Borda, an isolated plateau 300–800 meters above sea level, and possess a behavior very uncommon within the genus, being a mid-water pelagic fish, instead of the benthic behavior of most congeners. Comments on the putative phylogenetic relationships of the new species, as well as some remarks on its unusual behavior within the genus, are presented
ARTIGO - Inglês
Assunto: Classificação
A new species of Cyphocharax is described from the rio Mentaí, a tributary of rio Arapiuns, lower rio Tapajós basin, Pará state, Brazil. The new...
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A new species of Cyphocharax is described from the rio Mentaí, a tributary of rio Arapiuns, lower rio Tapajós basin, Pará state, Brazil. The new species can be distinguished from its congeners by the combination of a rounded dark blotch at the caudal peduncle and a pattern of horizontal stripes formed by series of conspicuous dark spots situated over the center of the scales on the lateral and dorsolateral surfaces of the body. The new Cyphocharax is compared with similar congeners as C. helleri, C. multilineatus, and C. pantostictos. Comments on the distribution of C. multilineatus are provided
A new species of Hemigrammus (Characiformes: Characidae) from western Amazon river basin, Colombia
ARTIGO - Inglês
Assunto: Peixe de água doce
A new species of Hemigrammus is described from the Amazon Basin near Leticia, Departamento Amazonas, Colombia. In common with some congeners and some...
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A new species of Hemigrammus is described from the Amazon Basin near Leticia, Departamento Amazonas, Colombia. In common with some congeners and some Hyphessobrycon spp., the new species colour pattern lacks a humeral blotch but has a caudal-peduncle blotch. It can be distinguished from congeners with a similar colour pattern by having: a relatively deep body (30.2%–39.0% LS), 20–24 branched anal-fin rays, 6–8 perforated scales of the lateral line, anal-fin base without a conspicuous black stripe, 3–5 maxillary teeth, maxillary teeth with 1–3 cusps, a thin longitudinal midlateral line and a well-defined oval shaped caudal blotch, extending from caudal peduncle into the lower caudal-fin rays. Comparisons with congeners and with Hyphessobrycon species sharing the same general colour pattern are presented
ARTIGO - Inglês
Assunto: Peixe - Amazônia
Abstract: A new species of Hemigrammus is described from the middle rio Solimões/Amazonas and tributaries, upper and middle rio Madeira, and rio...
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Abstract: A new species of Hemigrammus is described from the middle rio Solimões/Amazonas and tributaries, upper and middle rio Madeira, and rio Paraná-Paraguai basins in Brazil and Paraguay. The new species is most similar among congeners with Hemigrammus marginatus, with which it shares similar caudal-fin pigmentation pattern. The new species can be distinguished from Hemigrammus marginatus by possessing two conspicuous dark patches of pigmentation on caudal fin, occupying most of caudal-fin lobes, except the tips, by having two dark narrow stripes along anal-fin base, and by possessing 5–8 pored lateral line scales. The new species differs from Hyphessobrycon diancistrus, which is similar in color pattern and general body shape, by the presence of small scales on caudal-fin lobes, occupying approximately its basal third, by the presence of two narrow stripes along anal fin base, and by the absence of bony hooks on analfin in mature males. The occurrence of the new species in both Amazon and rio Paraná-Paraguai basins is discussed in order to clarify and expand recent discussions on the biogeographical relationships between both river systems
ARTIGO - Inglês
Assunto: Biogeografia
A new Hemigrammus is described from the rio Paraguai and rio Madeira basins, Mato Grosso and Rondônia States, Brazil. The new species is characterized...
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A new Hemigrammus is described from the rio Paraguai and rio Madeira basins, Mato Grosso and Rondônia States, Brazil. The new species is characterized by possessing a wide dark horizontal stripe across the eye, a vertically elongated humeral blotch, and 4-5 gill-rakers on upper branch and 9-10 on lower. The new species can be easily diagnosed from H. lunatus, the sympatric and morphologically most similar congener, by the shape of humeral blotch and the number of gill rakers. Data of the type material of both Hemigrammus lunatus and H. maxillaris, as well as extensive examination of specimens, allowed us to conclude that H. maxillarisis a junior subjective synonym of H. lunatus. A redescription of H. lunatus, as well as a formal restriction of its type locality, is provided. A putative monophyletic group within Hemigrammus, composed by H. barrigonae, Hemigrammus lunatus, H. machadoi new species, and H. ulreyi, named Hemigrammus lunatus group, is proposed based on overall body morphology and color pattern. Additionally, a discussion on the biogeographical relationships between the rio Paraguai and rio Guaporé basins is provided
ARTIGO - Inglês
Assunto: Characideo
A new species of Hyphessobrycon is described from the Rio Papagaio, a tributary of the Rio Juruena, Rio Tapajos basin, Brazil. The new taxon can be...
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A new species of Hyphessobrycon is described from the Rio Papagaio, a tributary of the Rio Juruena, Rio Tapajos basin, Brazil. The new taxon can be distinguished from its congeners by having a well-defined and relatively narrow dark midlateral stripe on body extending from the upper half of the posterior margin of the eye to the middle caudal-fin rays, absence of a humeral blotch, 16-19 branched anal-fin rays, 2-4 maxillary teeth, six branched pelvic-fin rays, and the absence of dark pigmentation crossing the eye. Hyphessobrycon cyanotaenia, a species described from few specimens from the aquarium trade without precise locality, is redescribed herein based on extensive material, and its known distribution is discussed and rectified from the original description
ARTIGO - Inglês
Assunto: Peixe
A new species of Moenkhausia is described from Rio Curicuriari and Rio Tiquié, both right-bank tributaries of the upper Rio Negro basin, Amazonas...
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A new species of Moenkhausia is described from Rio Curicuriari and Rio Tiquié, both right-bank tributaries of the upper Rio Negro basin, Amazonas State, Brazil. The new taxon differs from all congeners, except M. agnesae and M. beninei, by the combination of a sinuous humeral blotch, similar to a compressed letter Z, and distinct dark longitudinal stripes along the body sides. The new species can be distinguished from M. agnesae and M. beninei by the presence of a single humeral blotch and of longitudinal stripes running through the center of the scales, more conspicuous dorsally
ARTIGO - Inglês
Assunto: Classificação
Abstract: A revision of the cis-andean species of Brycon, with the exception of the Brycon pesu species-complex, is presented. Twenty-one Brycon...
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Abstract: A revision of the cis-andean species of Brycon, with the exception of the Brycon pesu species-complex, is presented. Twenty-one Brycon species (including B. pesu) are recognized from cis-andean river systems: Brycon stolzmanni Steindachner, from the upper Río Marañon basin, Peru; Brycon coxeyi Fowler, from the Río Marañon basin, Ecuador and Peru; Brycon polylepis Moscó Morales, from the Lago de Maracaibo, Río Orinoco, upper rio Amazonas, and rio Tocantins basins, Venezuela, Colombia, Peru, and Brazil; Brycon coquenani Steindachner, from the upper Río Caroni, Río Orinoco basin, Venezuela; Brycon insignis Steindachner, from the rio Paraíba do Sul and small adjacent coastal river basins of eastern Brazil; Brycon vermelha Lima & Castro, endemic from the rio Mucuri basin, eastern Brazil; Brycon howesi new species, endemic from the rio Jequitinhonha basin, Brazil; Brycon dulcis new species, endemic from the rio Doce basin, eastern Brazil; Brycon ferox Steindachner, from several small coastal river systems, including the rio Mucuri basin in eastern Brazil; Brycon vonoi new species, from the rio Pardo basin and apparently also from a adjacent river system, the rio Una, in eastern Brazil; Brycon opalinus (Cuvier), from the headwaters of the rio Paraíba do Sul and rio Doce basins, eastern Brazil; Brycon nattereri Günther, from the headwaters of the upper rio Paraná, rio São Francisco, and upper rio Tocantins basins, Brazil; Brycon orthotaenia Günther, endemic from the rio São Francisco basin, Brazil; Brycon orbignyanus (Valenciennes), from the rio Paraná and rio Uruguai basins, Brazil, Paraguay, Argentina, and Uruguay; Brycon hilarii (Valenciennes), from the rio Paraguai, middle rio Paraná, and upper rio Amazonas basins, Brazil, Paraguay, Argentina, Peru, and Ecuador; Brycon whitei Myers & Weitzman, from the Río Orinoco basin in Colombia and Venezuela; Brycon amazonicus (Agassiz), from the Rio Amazonas and Río Orinoco basins, Brazil, Peru, Colombia, Bolivia, Venezuela, and Guyana; Brycon gouldingi Lima, endemic from the rio Tocantins basin, Brazil; Brycon melanopterus (Cope), from the western and central rio Amazonas basin, Brazil, Peru, Ecuador, and Colombia; and Brycon falcatus Müller & Troschel, widespread in the the rio Amazonas and Río Orinoco basins, and several guyanese river systems, in Brazil, Venezuela, Colombia, Peru, Bolivia, Guyana, Suriname, and French Guiana. All species are redescribed and illustrated, and a key to the species is provided. Comments on the diagnosis of the genus Brycon, the biogeography of the cis-andean species, and their current conservation status, are presented
ARTIGO - Inglês
Assunto: Água - Consumo
Abstract: Bromeliads as a water source for birds are seldom recorded in the scientific literature, despite the ubiquity of these plants in the...
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Abstract: Bromeliads as a water source for birds are seldom recorded in the scientific literature, despite the ubiquity of these plants in the Neotropics. We describe and illustrate herein the white-throated thrush and the dusky-legged guan drinking water from bromeliads at the Atlantic Forest biome in south-eastern Brazil. Additionally, we summarise bromeliad water drinking by birds in Brazil. The available records indicate that bromeliads as water source for birds are poorly known, and all records are from the Atlantic Forest biome. We expect that perceptive observations of birds probing into bromeliads will add more records of drinking behaviour from this source in Brazil, including the Amazonian forest and even the Caatinga biomes
ARTIGO - Inglês
Assunto: Artigo de dados de pesquisa
Bee in the nose : raptors let or let not stingless bees enter their nostrils
ARTIGO - Inglês
Assunto: Ave de rapina
Abstract: Relationships between birds and social insects include birds following ants, birds nesting close to active colonies of wasps or bees, and...
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Abstract: Relationships between birds and social insects include birds following ants, birds nesting close to active colonies of wasps or bees, and nesting inside termitaria. A little known relationship between birds and colonial insects is that of stingless bees (Meliponina) entering the nostrils of hawks and owls. Herein I report on a stingless bee entering the nostrils of the Roadside Hawk (Rupornis magnirostris), and on avoiding behaviours displayed by the same hawk species and a Burrowing Owl (Athene cunicularia) in presence of stingless bees hovering in front of their faces. The bees probably were seeking mucus inside the raptors’ nostrils, as already reported for a few birds of prey. Avoiding behaviour seems a novelty in this relationship between raptors and bees. The role stingless bees play in the lives of some bird species remains little known, and merits closer attention by field ornithologists and apidolologist
Texto completo: http://www.revbrasilornitol.com.br/BJO/article/view/1129
Behavioural and morphological traits influence sex-specific floral resource use by hummingbirds
ARTIGO - Inglês
Assunto: Artigo de pesquisa
Abstract: Research on resource partitioning in plant-pollinator mutualistic systems is mainly concentrated at the levels of species and communities,...
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Abstract: Research on resource partitioning in plant-pollinator mutualistic systems is mainly concentrated at the levels of species and communities, whereas differences between males and females are typically ignored. Nevertheless, pollinators often show large sexual differences in behaviour and morphology, which may lead to sex-specific patterns of resource use with the potential to differentially affect plant reproduction and diversification. We investigated variation in behavioural and morphological traits between sexes of hummingbird species as potential mechanisms underlying sex-specific flower resource use in ecological communities. To do so, we compiled a dataset of plant-hummingbird interactions based on pollen loads for 31 hummingbird species from 13 localities across the Americas, complemented by data on territorial behaviour (territorial or non-territorial) and morphological traits (bill length, bill curvature, wing length and body mass). We assessed the extent of intersexual differences in niche breadth and niche overlap in floral resource use across hummingbird species. Then, we tested whether floral niche breadth and overlap between sexes are associated with sexual dimorphism in behavioural or morphological traits of hummingbird species while accounting for evolutionary relatedness among the species. We found striking differences in patterns of floral resource use between sex. Females had a broader floral niche breadth and were more dissimilar in the plant species visited with respect to males of the same species, resulting in a high level of resource partitioning between sexes. We found that both territoriality and morphological traits were related to sex-specific resource use by hummingbird species. Notably, niche overlap between sexes was greater for territorial than non-territorial species, and moreover, niche overlap was negatively associated with sexual dimorphism in bill curvature across hummingbird species. These results reveal the importance of behavioural and morphological traits of hummingbird species in sex-specific resource use and that resource partitioning by sex is likely to be an important mechanism to reduce intersexual competition in hummingbirds. These findings highlight the need for better understanding the putative role of intersexual variation in shaping patterns of interactions and plant reproduction in ecological communities
Between fruits, flowers and nectar : the extraordinary diet of the frog Xenohyla truncata
ARTIGO - Inglês
Assunto: Interação animal-planta
Abstract: Pollination and seed dispersal are determinants for plant survivorship. Among land vertebrates, mammals and birds stand out in these...
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Abstract: Pollination and seed dispersal are determinants for plant survivorship. Among land vertebrates, mammals and birds stand out in these relationships with plants. On the other hand, frogs are not expected to play a role in these interactions, as nearly all species are carnivorous (mostly insectivorous) after metamorphosis. However, one species attracts attention: Xenohyla truncata, which includes plant parts on its natural diet. Recently, we observed unexpected interactions between this Neotropical treefrog and plants in their native range. The frog fed on different plant parts, consuming fruits, floral structures and nectar with suction-like movements, and we observed pollen grains adhered to the frog's back, which renders this treefrog as a potential pollinator, besides its already established role as seed disperser. Nectar ingestion during the reproductive season could benefit individuals under high energetic demand. This is a unique and outstanding example of unforeseen interactions between amphibians and plants
Birds preying on lizards at a suburban residential complex in Sydney, South Eastern Australia
ARTIGO - Inglês
Assunto: Ave
Abstract: Several bird species prey on small vertebrates including lizards, both in natural and human-modified environments. Reports on lizard...
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Abstract: Several bird species prey on small vertebrates including lizards, both in natural and human-modified environments. Reports on lizard predation by birds in urbanised areas are scarce, and the behaviours of the birds are rarely documented. I briefly describe and illustrate the behaviours of an assemblage of seven bird species preying on lizards at a suburban site in Sydney, New South Wales, South Eastern Australia. The assemblage was composed of four insectivorous–carnivorous species and three omnivorous ones. Hunting tactics varied from searching for lizards while walking to inspecting while perched. The birds preyed on one to three different lizard species of the six ones that I recorded in the study area. I recorded new prey species for five birds and a particular behaviour for two of them: targeting lizards as the only prey. These records add novel insights to bird–lizard preying interactions in urbanised landscapes. Studies on bird assemblages at urbanised sites should draw attention to reptile predation, among the factors that influence the response of reptiles to urbanisation
Bromeliad water-drinking birds in Brazil : outline based on a citizen science platform
ARTIGO - Inglês
Assunto: Biodiversidade - Mata Atlântica
Abstract: Bromeliads are ubiquitous and species-rich plants in the Atlantic Forest in Brazil, which hold water available for bird-drinking. Herein, we...
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Abstract: Bromeliads are ubiquitous and species-rich plants in the Atlantic Forest in Brazil, which hold water available for bird-drinking. Herein, we list and illustrate bromeliad water-drinking birds recorded by Brazilian citizen scientists and available at the public platform Wiki Aves. We found photographic records of 36 bird species in the platform. The records indicate that bromeliads as water source for birds originate entirely from the Atlantic Forest, as previously found in the scientific literature. Records of bromeliad water-drinking birds in north-western Brazil are absent from the platform, but there are records from north-eastern and southern Brazil, regions undetected in the scientific literature search. Literature and the present records of bromeliad-drinking birds in Brazil comprise 42 species in 15 families to date, of which 10 are non-passerines and the remaining ones are passerines. Based on previous research, expected bird species were in Ramphastidae, Picidae, Cotingidae, Tyrannidae, Turdidae, and Thraupidae, whereas unforeseen bird species include Psittacidae, Tytiridae, Rhynchocyclidae, Vireonidae, Mimidae, Fringillidae, and Icteridae. Amazonian bromeliad-drinking birds are still lacking, despite bromeliad richness in this biome. However, it should be noted that Amazon Forest harbour lower bromeliad species-richness than the Atlantic Forest. Additional search in citizen science databases and fieldwork are needed to fill this gap
Cicada feast and food links : grey-headed flying fox preys on black prince in south-east Australia
ARTIGO - Inglês
Assunto: Cigarra
Abstract: Cicada mass emergence offers a plentiful and energy-rich food source for a variety of predators, mainly birds and spiders. Megabats...
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Abstract: Cicada mass emergence offers a plentiful and energy-rich food source for a variety of predators, mainly birds and spiders. Megabats (Pteropodidae) mostly feed on nectar and fruits, but occasionally prey on insects such as sap-sucking cicadas and fruit-eating beetles. We observed and documented with photographs the behavioural repertoire of the Grey-headed Flying Fox Pteropus poliocephalus while hunting and consuming the Black Prince cicada Psaltoda plaga in Sydney, New South Wales, Australia. The bats used three main tactics while hunting the cicadas: a) flushing and/or catching cicadas on tree foliage while clambering over branches or landing on the foliage, b) lunging from a perch after spotting a resting cicada, and c) pursuing cicadas on the wing. Upon securing a cicada the bats flew off and landed on a feeding perch, where they chewed the prey and spat the remains as a pellet below this perch. On the ground, the pellets were usually sought by large ants that tore off pieces from these remains, the ants transporting them to the nest. Small ants aggregated on the pellets probably to seek the remaining sap, after which they left the pellets. The above described events showed three main food links: a) cicadas feeding on plant sap, b) bats preying on cicadas and spitting the remains as pellets, and c) ants feeding on bat pellets. The links illustrate a food chain that include plants, cicadas, bats, and ants. Additional food links we observed were: 1) cicadas feeding on different plants, 2) cicadas preyed on by diurnal animals, 3) dead cicadas consumed by ants, 4) dead bats consumed by birds, and 5) nocturnal raptorial bird that may prey on bats. This report seems the first to mention food links within a megabat-insect trophic interaction
ARTIGO - Inglês
Assunto: Anhingidae
Abstract: Impacts of anthropogenic inedible debris on seabirds have been well documented, but on inland waterbirds this kind of pollution remains...
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Abstract: Impacts of anthropogenic inedible debris on seabirds have been well documented, but on inland waterbirds this kind of pollution remains poorly recorded. Herein we report 21 instances of inedible objects stuck in the bill of Anhinga (Anhinga anhinga), a fish-eating waterbird which has the cutting edges of the mandible serrated. Disturbance and harm by pieces of plastic, rope, and cotton stuck in the bill were recorded. Debris caused drag and prevented the birds from fishing. Birds with small pieces of material stuck on their bills were still able to fish, but their hunting success decreased. When the debris was large and stuck on the bill for long, the birds possibly starved and some of them died. The time spent to clean up the bill was related to the type of material, ranging from 1 to 17 days. Our records illustrate the deleterious effect that anthropogenic debris has on the life of a Neotropical aquatic inland bird
DOI: https://doi.org/10.1007/BF03544312
Texto completo: https://link.springer.com/article/10.1007%2FBF03544312
ARTIGO - Inglês
Assunto: Zoologia - Classificação
After 80 years of misidentifications, the analysis of the holotype of Corydoras arcuatus plus several non-type specimens attributed to this species...
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After 80 years of misidentifications, the analysis of the holotype of Corydoras arcuatus plus several non-type specimens attributed to this species allowed its recognition and also revealed a new species, both sharing the following diagnostic features: a long, arched, continuous black stripe that runs parallel to the dorsal profile of the body and extends at least from the anterior margin of the first dorsolateral body plate to the posterior portion of caudal peduncle; absence of transverse black bars on caudal fin; infraorbital 2 in contact with sphenotic and compound pterotic. In addition to these features, C. arcuatus can be distinguished from congeners by having the posterior margin of both dorsal and pectoral spines with laminar serrations directed towards their origins. The new species can be additionally distinguished from its congeners by presenting the following combination of features: ventral surface of trunk entirely or partially covered by relatively large and coalescent platelets; absence of spots or blotches on dorsal fin; and posterior margin of both dorsal and pectoral spines with serrations directed towards their tips. Finally, an identification key to all arc-striped species of Corydoras is provided
ARTIGO - Inglês
Assunto: Peixe - Comportamento
Abstract: Feeding ecology studies are crucial for understanding energy flow in reef ecosystems. In this study, we used an integrative approach to...
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Abstract: Feeding ecology studies are crucial for understanding energy flow in reef ecosystems. In this study, we used an integrative approach to investigate the diel-feeding ecology of the sergeant-major Abudefduf saxatilis. To examine the possibility of diel-periodicity and size-class differences in foraging behaviour, we tracked fish individuals until their first bite on two subtropical reefs. During each observation, we recorded the substratum that was bitten and estimated the individual’s total length. To assess the diet, we analysed the stomach contents of five individuals from each location. In total, we observed 2,703 individuals biting seven substrates. Our results showed no significant differences in substrate use for diel-periodicity. However, we found significant differences between two size classes. Despite this, both populations tended to forage near the surface in the water column in the morning and on the benthos in the afternoon, although this tendency was not statistically significant. Smaller individuals fed mostly in the water column, while larger individuals foraged on all substrates, likely due to their different energetic demands. Our findings indicate this species has an omnivorous, generalist diet, comprising 12 items from both benthos and plankton. The lack of differences in diel-periodicity is likely due to the sergeant-major’s opportunistic behaviour