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

2024 ◽  
Vol 84 ◽  
Author(s):  
F. M. Dutra-Vieira ◽  
M. S. Silva ◽  
G. S. Vieira ◽  
A. S. Carvalho ◽  
B. C. Schimming

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.

2020 ◽  
Vol 32 ◽  
Author(s):  
Tatiane Araujo Santos ◽  
Thamires Souza Gonçalves ◽  
Patricia Silva do Nascimento ◽  
Cézar Augusto Freire Fernandes ◽  
Francisca Edna de Andrade Cunha

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.


2008 ◽  
Vol 68 (2) ◽  
pp. 321-328 ◽  
Author(s):  
LM. Gomiero ◽  
AG. Manzatto ◽  
FMS. Braga

The purpose of this study was to characterize the diet of the fish Brycon opalinus (Characidae) seasonally and locally, allowing for the determination of its food items and trophic relations with the aquatic and terrestrial environments. The study area encompasses three rivers (Paraibuna, Ipiranga and Grande) in the basin of the Paraibuna, southeast Brazil. Twelve monthly collections were made from January to December 2004. The degree of stomachic repletion and of accumulated visceral fat was analyzed, as was the intestinal length in each class of total length. The frequency of occurrence and the degree of food preference (DFP) of the food items of Brycon opalinus were determined by separating the vegetal and animal items, autochthonous and allochthonous, by insect order and vegetal family consumed. The frequency of occurrence of items of animal origin was found to be equivalent to that of vegetal origin, thus characterizing the omnivorism of Brycon opalinus feeding.


Author(s):  
Edem, Edem Thomas ◽  
Patience B. Opeh

The present study is aimed to provide information on the food and feeding habit of adult Auchenoglanis biscutatus in Lower River Benue. The natural food of A. biscutatus in the Lower River Benue was studied from stomach contents of the fish. The stomach contents were analyzed using two methods; the frequency of occurrence and point methods. A total of 100 stomachs were randomly examined. Eleven major items constituted the diet of A. biscutatus. The stomach content analysis of A. biscutatus have shown that they fed on the various food items ranging from plant parts, detritus, seeds, digested food particles, fish parts, mollusc, sand/mud, insect parts and algae. This indicates that A. biscutatus is an omnivorous bottom feeder since; bottom dwelling immature insects dominated most of the food items of animal origin, digested food and detritus. A. biscutatus in Lower Benue River feeds on a wide range of food items which could make it to be regarded as an omnivore. Future attempts to culture this species must take cognizance of its food habits in the wild.


2017 ◽  
Vol 17 (1) ◽  
Author(s):  
Suzanne Fernandes ◽  
Rafael Pereira Leitão ◽  
Eurizângela Pereira Dary ◽  
Ana Isabel Camacho Guerreiro ◽  
Jansen Zuanon ◽  
...  

Abstract This study assessed the diet of two poorly known syntopic fish species of the family Crenuchidae, Characidium aff. declivirostre and Leptocharacidium omospilus, in a Presidente Figueiredo´ rocky stream, Amazonas, Brazil. The stomach contents were analyzed and their Frequency of Occurrence (FO %) and Relative Volume (Vol %) were combined in a Feeding Index (IAi). We examined 20 individuals of C. aff. declivirostre and 23 of L. omospilus. The Morisita-Horn Index was used to estimate the overlap between the diets of these species. Immature insects were the most valuable items consumed by both fish species. The diet of C. aff. declivirostre was mainly composed of larvae and pupae of Chironomidae, while L. omospilus predominantly consumed larvae of Hydroptilidae, Hydropyschidae and Pyralidae. Thus, both species were classified as autochthonous insectivorous. Characidium aff. declivirostre was considered a more specialized species, probably reflecting lower feeding plasticity or the use of more restricted microhabitats compared to L. omospilus. When the food items were analyzed at the family taxonomic level, the diet overlap between these species was considered moderate (Morisita-Horn Index = 0.4). However, a more thorough analysis, at the genus level, indicates a very low diet overlap. Therefore, we conclude that the feeding segregation between C. aff. declivirostre and L. omospilus may favor their co-existence, despite their high phylogenetic closeness.


2013 ◽  
Vol 25 (1) ◽  
pp. 34-41 ◽  
Author(s):  
Márcia Emília de Jesus Trindade ◽  
Alexandre Peressin ◽  
Maurício Cetra ◽  
Ricardo Jucá-Chagas

AIM: in this study we present data from the diet of Astyanax vermilion which were used as a tool to compare two sites of streams with different vegetation cover in Ribeirão Limoeiro, Cachoeira River Basin, BA. METHODS: Four samples were taken (March, June, September and December) using electrofishing as the collection method in two contiguous sites of the headwaters: stretch without riparian vegetation and with riparian vegetation. RESULTS: The qualitative composition of the diet was analyzed by the method of frequency of occurrence. The allochthonous resources of vegetal origin made up the bulk of the diet in the stretch without riparian vegetation with a frequency of occurrence of 64%. In the section with riparian vegetation allochthonous resources of animal origin made up the bulk of the diet with a frequency of 62%, which emphasizes the importance of food items from the surrounding environment. The mean Shannon diversity index, calculated from the frequency of occurrence of food items was significantly different (p = 0.04) when comparing reach deforested (H'= 1.44) with reach forested (H'= 1.80). The average weight of stomachs in the deforested reach (WS D = 0.18g) was significantly higher than that of the forested reach (WS F = 0.14g). CONCLUSIONS: in the stretch with riparian vegetation, the food diversity was greater and the fish that are in the riparian stretch do not need as much food to satisfy their physiological needs. These results underscore the importance of the type of riparian vegetation as a food source for fish


2013 ◽  
Vol 13 (1) ◽  
pp. 376-379 ◽  
Author(s):  
Akemi Shibuya ◽  
Jansen Zuanon

In spite of the fact that catfish have rarely been reported as food items in the diets of freshwater stingrays, they are commonly observed in the stomach contents of species inhabiting the Solimões and Negro rivers in the Brazilian Amazon. The stomach contents of six rays from the Solimões River and 64 from the Negro River were analyzed, and catfishes (distributed among the families Callichthyidae, Cetopsidae, Doradidae and Loricariidae) were found in the stomach contents of four and 10 of these rays, respectively, comprising a frequency of occurrence of 20%. These data indicate a relevant participation of catfishes in the diets of potamotrygonid rays in the Amazon, and may reflect the regional diversity and abundance of Siluriformes in the region.


2022 ◽  
Vol 14 (2) ◽  
pp. 974
Author(s):  
Mathewos Temesgen ◽  
Abebe Getahun ◽  
Brook Lemma ◽  
Geert P. J. Janssens

This study aimed to investigate the natural feeding behavior of Nile tilapia in Lake Langeno, Ethiopia, with emphasis on potential spatial, size and seasonal effects on ingested food items. This study of the food and feeding biology of O. niloticus in Lake Langeno, Ethiopia, was conducted from March 2016to February 2017. Fish samples were collected monthly from six different sampling sites using different mesh sizes of gillnets. A total of 610 fish specimens with full stomachs were considered for the assessment of feeding biology. In total, seven food items, namely phytoplankton, zooplankton, insects, detritus, macrophytes, fish parts and nematodes, were identified from the fish stomach contents. Phytoplankton was the most commonly consumed food prey, followed by detritus, zooplankton and macrophytes. The other food items were occasionally and randomly consumed. Phytoplankton and detritus were the dominant food prey in the dry season, with zooplankton and macrophytes the main prey during the wet months. The contribution of phytoplankton, zooplankton and insects were slightly highest in small-sized groups (<10 cm), whereas detritus, macrophytes and fish parts were highest in larger-size groups (>20 cm) (p < 0.05). The present results point to a concurrence of the relative importance of dietary items at the individual level, species level and among the study sites. Phytoplankton was the primary consumed food item, which indicates the specialist feeding strategy of Nile tilapia in the lake. Generally, food items of plant origin, typically associated with less protein content than animal origin food items, dominated the stomach contents of Nile tilapia. The dietary pattern of Nile tilapia in Lake Langeno shifts with size and season, aspects that might warrant further study in view of aquaculture applications as well as climate change.


Author(s):  
Martha L. Cortés ◽  
María M. Críales

Juveniles and adults of the seabob Xiphopenaeus kroyeri (Heller) were collected at monthly invervals between September 1988 and June 1988. The food items were determined in order of descending importance as: detritus and fragments of bivalve shells, polychaete worms, foraminiferans, and crustaceans. There was a difference in the feeding habits between the rainy seasson (September to December) and the dry season (January to June) with items like rotifers, sponges and radiolarians appearing only during the dry season. Analysis of the frequency of occurrence of different food items showed that groups like rotifers and bryozoans appear more frequently in juveniles. Measurements of protein and carbohydrate levels in the stomach contents revealed the highest peaks of proteins for adults in September (92.03 ug/mg dry weight of stomach contents) and for juveniles in December (81.27 ug/mg), and of carbohydrates for adults in October (45.81 ug/mg) and for juveniles in December (35.25 ug/mg). Quantitative differences in proteins and carbohydrates between the two size groups were not statistically significant.


2009 ◽  
Vol 7 (2) ◽  
pp. 257-266 ◽  
Author(s):  
Luciano Lazzarini Wolff ◽  
Vinícius Abilhoa ◽  
Flavia Sant'Anna Rios ◽  
Lucélia Donatti

This study described the feeding habits of the characin Astyanax aff. fasciatus. The diet compositions of specimens from two sites (A and B) on a river in Southern Brazil were compared according to the size of individuals and seasonal period. The collections were performed monthly from March 2005 to February 2006, where the stomach contents of 290 specimens were assessed. Food items for A. aff. fasciatus were basically composed of plants and insects, especially leaf fragments, seeds, fruits, filamentous algae, aquatic and terrestrial insects and insect fragments. At site A, the most common items were insect and plant fragments. Conversely at site B, plant fragments were more representative. In general, all items of animal origin showed the highest feeding index values at site A, whereas at site B detritus and grass items were more abundant. The composition of items varied seasonally, with higher diversity of items being recorded during the spring at both sites. Smaller individuals preferred items of animal origin, while the larger ones consumed mainly items of plant origin. According to its size, A. aff. fasciatus in this study may be considered a species with insectivorous tendencies when immature or herbivorous tendencies when adult. Nevertheless, its feeding habits may be flexible according to resource availability, showing wide ontogenetic, besides spatial and temporal variation.


2005 ◽  
Vol 24 (4) ◽  
pp. 118-123
Author(s):  
O. B. Kok ◽  
S.v.d. M. Louw ◽  
A. C. Kok

Analyses of 326 white-quilled korhaan (Eupodotis afraoides) stomach contents collected in the Free State and Northern Cape over a period of 20 years (1984-2004) showed this species to be a mixed feeder concentrating mainly on insects. Based on dry mass prey items of the Isoptera and Coleoptera form the bulk of the diet. According to frequency of occurrence coleopterans, more specifically members of the family Curculionidae, are utilised most often. Indications are that the curculionids, owing to their size and relative hardness of the exoskeleton, fulfil an accessory function with regard to the physical breakdown of coarse food items in the muscular stomach.


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