Diel feeding pattern and diet of rough scad Trachurus lathami Nichols, 1920 (Carangidae) from the Southwestern Atlantic

Diel changes in feeding activity and dietary composition of the rough scad Trachurus lathami were investigated through the analysis of stomach contents of 307 fish sampled over a 24-h period on the continental shelf off Ubatuba (23º 35'S 45ºW). Stomach contents were analyzed by frequency of occurrence (O%), percent number (N%), percent mass (M%), and feeding index (FI% = O% * M%). Rough scad fed on mollusks (Gastropoda, Crepidula sp.), crustacean (Ostracoda, Copepoda, decapod larvae), chaetognat and teleostean fish. The main items were calanoid copepods (Eucalanus sp. and Centropages sp.). According to the analysis of the stomach fullness and prey digestion, T. lathami is both a diurnal and nocturnal feeder, showing some seasonal variation in feeding time. According to the Chronobiology concept, it was raised the hypothesis of circadian rhythm in feeding of this fish, probably synchronized by light/dark cycle.

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diet and feeding of the cutlassfish trichiurus lepturus in the subtropical convergence ecosystem of southern brazil

Journal of the Marine Biological Association of the United Kingdom ◽

10.1017/s002531540501235x ◽

2005 ◽

Vol 85 (5) ◽

pp. 1223-1229 ◽

Cited By ~ 40

Author(s):

agnaldo s. martins ◽

manuel haimovici ◽

raul palacios

Keyword(s):

Cold Water ◽

Feeding Activity ◽

Warm Season ◽

Stomach Contents ◽

Small Fish ◽

Southern Brazil ◽

Calanoid Copepods ◽

Diet Diversity ◽

Trichiurus Lepturus ◽

Wide Range

the diet and feeding of the cutlassfish trichiurus lepturus were studied based on analyses of the stomach contents of larvae, juveniles, and adults collected along the continental shelf and shelf break off southern brazil, from the cape of santa marta grande (28°36′s) to chuí (34°45′s). the larvae and pre-juveniles with a total length of <5 cm were found to have fed almost exclusively on calanoid copepods, whereas juveniles (5 to 30 cm) fed on small zooplanktonic crustaceans such as lucifer faxoni and promysys atlantica. on the other hand, sub-adults (30 to 70 cm), fed on euphausiids, mainly euphausia similis, and small fish, mostly anchovy engraulis anchoita. adults (70 to 160 cm) fed on a wide range of larger prey, such as anchovy, sciaenid fish, cephalopods and coastal shrimps, as well as euphausiids. the juveniles and sub-adults fed more intensively than adults during the warm-water season whereas adults fed more intensively during the cold-water season. feeding activity was more intense at night, while cannibalism was more frequent during the warm season, when biological productivity was lower. finally, diet diversity was higher in coastal waters, during the warm season. the abundance of cutlassfish off southern brazil may be explained by the fact that it is adapted to feed on a wide size-range of both pelagic and demersal prey.

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Effects of light-dark cycle on the spatial distribution and feeding activity of fish larvae of two co-occurring species (Pisces: Hypophthalmidae and Sciaenidae) in a Neotropical floodplain lake

Brazilian Journal of Biology ◽

10.1590/1519-6984.179070 ◽

2018 ◽

Vol 78 (4) ◽

pp. 763-772 ◽

Cited By ~ 4

Author(s):

P. H. S. Picapedra ◽

P. V. Sanches ◽

F. A. Lansac-Tôha

Keyword(s):

Spatial Distribution ◽

Feeding Behavior ◽

Fish Larvae ◽

Feeding Activity ◽

Food Distribution ◽

Floodplain Lake ◽

Calanoid Copepods ◽

Natural Ecosystems ◽

Dark Cycle ◽

Food Items

Abstract Most studies on mechanisms regulating fish larvae processes have focused on assessing the isolated effects of food distribution and feeding behavior. However, in natural ecosystems, fish larvae may strongly interact with zooplankton organisms in an array of complex, direct and indirect interdependencies. This study analyzed the spatial distribution, diet and feeding behavior of early stages of Hypophthalmus edentatus and Plagioscion squamosissimus, two fish species co-occurring in an isolated floodplain lake, during the light-dark cycle. Larvae fed more actively during dark periods (dusk and night) when they migrated toward the surface of the lake, and remained on the bottom and fed less during light periods (day and dawn). Cladocerans represented the most frequent prey in the diet of H. edentatus larvae. In turn, P. squamosissimus larvae initially preferred cladocerans and, as they developed, included calanoid copepods in the diet. Significant differences were detected in the frequencies of food items consumed during larval development, which could be related to a better ability of the most developed stages to explore the environment in search of other prey.

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Prey consumed by Guiana dolphin Sotalia guianensis (Cetacea, Delphinidae) and franciscana dolphin Pontoporia blainvillei (Cetacea, Pontoporiidae) in an estuarine environment in southern Brazil

Iheringia Série Zoologia ◽

10.1590/s0073-47212012000200003 ◽

2012 ◽

Vol 102 (2) ◽

pp. 131-137 ◽

Cited By ~ 20

Author(s):

Marta J. Cremer ◽

Pedro C. Pinheiro ◽

Paulo C. Simões-Lopes

Keyword(s):

Prey Species ◽

Stomach Contents ◽

Frequency Of Occurrence ◽

Teleost Fishes ◽

Southern Brazil ◽

Sympatric Populations ◽

Sotalia Guianensis ◽

Important Prey ◽

Pontoporia Blainvillei ◽

Lolliguncula Brevis

The present study provides information about the diet of sympatric populations of small cetaceans in the Babitonga Bay estuary. This is the first study on the diet of these species in direct sympatry. The stomach contents of seven Guiana dolphins Sotalia guianensis and eight franciscanas Pontoporia blainvillei were analyzed. The prey of both cetaceans was mostly teleost fishes, followed by cephalopods. We identified 13 teleost fishes as part of the diet of the franciscanas, and 20 as part of the diet of Guiana dolphins. Lolliguncula brevis was the only cephalopod recorded, and was the most important prey for both cetaceans. Stellifer rastrifer and Gobionellus oceanicus were also important for franciscana, so as Mugil curema and Micropogonias furnieri were important for Guiana dolphins. Stellifer rastrifer and Cetengraulis edentulus were the fishes with the highest frequency of occurrence for franciscana (50%), while Achirus lineatus, C. edentulus, S. brasiliensis, Cynoscion leiarchus, M. furnieri, M. curema, Diapterus rhombeus, Eugerres brasilianus and G. oceanicus showed 28.6% of frequency of occurrence for Guiana dolphins. Franciscanas captured greater cephalopods than the Guiana dolphins in both total length (z= -3.38; n= 40; p< 0.05) and biomass (z = -2.46; n = 40; p<0.05). All of the prey species identified occur inside the estuary, which represents a safe habitat against predators and food availability, reinforcing the importance of the Babitonga Bay for these cetacean populations.

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Feeding behavior of lambs fed castor mealom farelo de mamona

Semina Ciências Agrárias ◽

10.5433/1679-0359.2016v37n3p1451 ◽

2016 ◽

Vol 37 (3) ◽

pp. 1451 ◽

Cited By ~ 2

Author(s):

Hellenn Cardoso Oliveira ◽

Rasmo Garcia ◽

Vitor Visintin Silva de Almeida ◽

Aline Cardoso Oliveira ◽

Aureliano José Vieira Pires ◽

...

Keyword(s):

Feeding Behavior ◽

Soybean Meal ◽

Feed Efficiency ◽

Dry Matter ◽

Feeding Activity ◽

Experimental Period ◽

Feeding Time ◽

Adaptation Period ◽

Four Levels ◽

Castor Meal

The experiment aimed to evaluate the feeding behavior of Santa Inês lambs fed diets containing different levels of detoxified castor meal in the concentrate. Twenty-four sheep with an average body weight of 18.5± 2.26 kg, at four months of age, were distributed in a randomized complete design with four treatment and six replications. Treatments consisted of four levels of castor meal (0, 33, 67, and 100%) replacing soybean meal. Animals underwent a 15-day adaptation period and an experimental period of 84 days. The diet was composed of 60% sugarcane silage and 40% concentrate, on a dry matter basis. Animal behavior (idle, rumination, and feeding activities) were observed visually for two 24-h periods with 5-min intervals, and recorded. The number of rumination chews and the time taken to ruminate each cud per day were counted using a digital stopwatch. Dry matter (DM) intake was not affected by inclusion of castor meal in the concentrate, averaging 884.02 g day?1. The feeding activity was not affected by addition of castor meal. Rumination time increased linearly, whereas the idle and rumination times decreased linearly with addition of castor meal. Feeding time, expressed in min per kg of DM and NDF, was not influenced by the inclusion of the meal in the diet, averaging 373.3 and 880.0 min, respectively. The number of chews and the time taken to ruminate each cud were not changed by inclusion of castor meal in the diet. Feed efficiency, expressed in grams DM and NDF per hour, was not influenced by castor meal inclusion in the diet. Rumination efficiency expressed in g DM h?1 decreased, but was not affected when expressed in g NDF h?1. Total replacement of soybean meal by castor meal in the concentrate does not affect the feeding time or feed efficiency of feedlot sheep, but leads to a small reduction of their rumination efficiency. Thus, we recommend the inclusion of castor meal in sheep diets at the levels tested in this study.

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Seasonal variation on diet of juvenile Elops saurus Linnaeus, 1766 (Ladyfish) in the Parnaiba River Delta

Acta Limnologica Brasiliensia ◽

10.1590/s2179-975x8818 ◽

2020 ◽

Vol 32 ◽

Cited By ~ 1

Author(s):

Tatiane Araujo Santos ◽

Thamires Souza Gonçalves ◽

Patricia Silva do Nascimento ◽

Cézar Augusto Freire Fernandes ◽

Francisca Edna de Andrade Cunha

Keyword(s):

High Frequency ◽

Rainy Season ◽

Stomach Contents ◽

Dry Season ◽

River Delta ◽

Frequency Of Occurrence ◽

Relative Importance ◽

Dry Period ◽

Food Items ◽

Importance Index

Abstract: Aim Identify seasonal variations in the diet of juvenile living in the estuary of the Parnaíba River Delta. Methods Food items were identified through analysis of stomach contents, and later submitted to analysis by regular methods for Frequency of Occurrence (FO), Frequency Numerical (FN), Gravimetric Frequency (FW) and Relative Importance Index (IRI). Results Juvenile diet of Elops saurus that inhabit the lagoons in the Parnaíba delta was composed in order decreasing of importance by Osteichthyes (Teleostei), Insecta and Crustacea in addition to Polychaeta and Nematoda. It was also observed a high frequency of occurrence of fragments of plastics in the diet. In the rainy season, 17 items were recorded in the diet, whereas in the dry season only 7 items were present. Relative Importance Index showed high presence of the Teleostei fish (69.93%) on diet of E. saurus during the rainy season, whereas during the dry period the insects of the families Corixidae (43.25%) and Dysticidae (39.16%). Conclusions With the study it was possible to identify that juvenile are piscivorous in the rainy season when there is a higher availability of prey in the environment and insectivores in the dry season when it reduces the supply of food, indicating feeding flexibility to environmental alterations.

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Diet of crab-eating fox (Cerdocyon thous) in two conservation units of the Amazon rainforest, Brazil

Brazilian Journal of Biology ◽

10.1590/1519-6984.252093 ◽

2024 ◽

Vol 84 ◽

Author(s):

F. M. Dutra-Vieira ◽

M. S. Silva ◽

G. S. Vieira ◽

A. S. Carvalho ◽

B. C. Schimming

Keyword(s):

Dry Matter ◽

Amazon Basin ◽

Stomach Contents ◽

Amazon Rainforest ◽

Animal Origin ◽

Mineral Matter ◽

Frequency Of Occurrence ◽

Conservation Units ◽

Food Items ◽

Cerdocyon Thous

Abstract The present study aimed to evaluate the diet of the free-living crab-eating fox by identifying the stomach contents of the 17 crab-eating foxes (Cerdocyon thous) roadkilled in two conservation units, both located in the Amazon rainforest. The food items were quantified by frequency of occurrence (FO) and percentage of occurrence (PO). The stomach contents were analysed for dry matter (DM), crude protein (CP), crude fibre (CF), ether extract (EE), and mineral matter (MM). Nitrogen-free extractives (NFE), metabolisable energy (ME) values, as well as the energy need for maintenance were estimated. The composition of the diet for the crab-eating fox presented 29 food items from the different taxonomic groups, with a greater diversity of items of animal origin (n=22), although the highest frequency of occurrence was gramineae (Poaceae) (41.18%). Among the items of animal origin, 21% were mammals, 18% reptiles, 10% amphibians, 9% invertebrates and 3% birds. A high content of CF (62.76%) were determined. Nitrogen-free extractive and dry matter averages were 5.91% and 141.82 kcal/100g, respectively. The average maintenance energy was 447.01 kcal/day. These findings suggesting that the crab-eating foxes have a generalist diet with an omnivorous diet in the Amazon basin, feeding on gramineae, fruits, insects, snakes, amphibians, birds and small mammals and have the same feeding habit that present in other Brazilian biomes.

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Inter-Population Similarities and Differences in Predation Efficiency of a Mosquito Natural Enemy

Journal of Medical Entomology ◽

10.1093/jme/tjaa093 ◽

2020 ◽

Vol 57 (6) ◽

pp. 1983-1987

Author(s):

Ross N Cuthbert ◽

Tatenda Dalu ◽

Ryan J Wasserman ◽

Olaf L F Weyl ◽

P William Froneman ◽

...

Keyword(s):

Critical Factor ◽

Population Variation ◽

Temporary Pond ◽

Feeding Time ◽

Eastern Cape ◽

Feeding Rates ◽

Calanoid Copepods ◽

Disease Vector ◽

Vector Mosquito ◽

Predation Efficiency

Abstract Predation is a critical factor that mediates population stability, community structure, and ecosystem function. Predatory natural enemies can contribute to the regulation of disease vector groups such as mosquitoes, particularly where they naturally co-occur across landscapes. However, we must understand inter-population variation in predatory efficiency if we are to enhance vector control. The present study thus employs a functional response (FR; resource use under different densities) approach to quantify and compare predatory interaction strengths among six populations of a predatory temporary pond specialist copepod, Lovenula raynerae, from the Eastern Cape of South Africa preying on second instar Culex pipiens complex mosquito larvae. All individuals from the sampled populations were predatory and drove significant mortality through per capita predation rates of 0.75–1.10 mosquitoes/h at maximum densities over a 5-h feeding time. Individuals from all copepod populations exhibited Type II FRs with no significant differences in attack rates. On the other hand, there were significant differences in handling times, and therefore also maximum feeding rates (maximum experimental prey density: 32), suggesting possible genetic differences among populations that influenced predation. Owing to a widespread distribution in arid landscapes, we propose that predatory calanoid copepods such as L. raynerae play a key regulatory role at the landscape scale in the control of disease vector mosquito populations. We propose that these ecosystems and their specialist biota should thus be conserved and enhanced (e.g., via selective breeding) owing to the ecosystem services they provide in the context of public health.

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Variations of Salminus hilarii diet (Ostariophysi, Characidae): seasonal and ontogenetic effects

Brazilian Journal of Biology ◽

10.1590/1519-6984.17213 ◽

2015 ◽

Vol 75 (3) ◽

pp. 574-580

Author(s):

GA Villares Junior ◽

R Goitein

Keyword(s):

Prey Size ◽

Pearson Correlation ◽

Feeding Activity ◽

Stomach Contents ◽

Food Composition ◽

Spearman Correlation ◽

Statistical Comparison ◽

Significant Difference ◽

Ontogenetic Effects ◽

Size And Morphology

AbstractThis study described the variations seasonal and ontogenetic of Salminus hilarii diet. Samples were collected in the Sorocaba River, São Paulo, Brazil, one of the few rivers where individuals of the species still occur in a higher frequency. The preys consumed were analyzed by Importance Alimentary Index (AIi). To determine similarities between year seasons, the AIi data were analyzed by the Morisita-Horn index and reduced in cluster analysis, along with a statistical comparison made by one-way ANOSIM test (5%). The feeding activity was analyzed according to the stomach repletion index and compared among the year seasons using non parametric variance analysis Kruskal-Wallis test (5%). Comparison of prey consumed between immature and adult individuals was made by Spearman correlation (5%). A Pearson correlation (5%) was applied between the standard length of the fish and prey consumed, as well as between the mouth and prey heights. The analyzes of stomach contents showed that the diet of this species was exclusively piscivorous, with significant difference of prey consumption during the period, the same happening among adult and immature individuals. It was observed that these fishes use to swallow their prey whole and that significant correlations between size of predator and prey size can be observed. There is also correlation between the mouth height and the maximum prey depth. Salminus hilarii feeds on the available prey, and the species food composition and feeding activity depends on prey`s abundance, their size and morphology, as do the water temperatures.

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