scholarly journals Catfishes as prey items of Potamotrygonid stingrays in the Solimões and Negro rivers, Brazilian Amazon

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.

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.


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.


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.


Author(s):  
Gabriel N. Genzano

The trophic ecology and seasonal changes in the diet of the intertidal hydrozoan Tubularia crocea were studied analysing the enteron contents of hydranths collected each season of the year. The relationship between feeding rate, prey availability, and re-suspension processes caused by tidal currents was also assessed. The most prevalent food items were diatoms and crustaceans. The most remarkable differences occurred during summer, when crustaceans were more abundant than diatoms. Conversely, diatoms were the most abundant prey during other seasons, and they were almost the only prey found during winter. There was no relationship between abundances of primary prey items in the water column and their occurrences in stomach contents. Instead, most prey items consisted of benthic organisms, primarily two species of diatoms (Grammatophora marina and Licmophora abreviatta) and fragments (usually appendages) of the amphipods Caprella sp. and Jassa falcata. Most food items were digested within 4–4·5 hours. The mean number of items captured per polyp per day was determined to be 115·2±19·2 in summer, 93·6±14·4 in autumn, 76·8±21·6 in winter and 199·2±31·2 in spring. Prey biomass (dry weight) polyp−1 d−1 was 5·1 μg in summer, 2·3 μg in autumn, 1·8 μg in winter, and 6·3 μg in spring. These values, in relation to hydranth biomass (55·3 μg; dry weight), were equivalent to a food intake polyp−1 d−1 of 9·3%, 4·2%, 3·2% and 11·5% of its own weight, respectively.


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.


2001 ◽  
Vol 28 (2) ◽  
pp. 121 ◽  
Author(s):  
Lesley A. Gibson

Diet and food availability of the greater bilby (Macrotis lagotis), was examined at two sites and over two summer and two winter seasons in Astrebla Downs National Park in south-western Queensland. The presence of both invertebrate and plant material in almost all faecal pellets (99.6% and 98.5%, respectively) indicated that bilbies in south-western Queensland are omnivorous. The plant component of the bilby diet consisted predominantly of Dactyloctenium radulans seeds (frequency of occurrence: 94.4%). The major invertebrate prey items were Isop-tera (termites, 73.1%) and Formicidae (ants, 77.6%). The frequency of occurrence of invertebrates in faecal pellets was higher during summer than winter, but the frequency of occurrence of plants was relatively constant regardless of season. Within the invertebrate categories, Isoptera and Acrididae (grasshoppers) displayed the greatest seasonal difference, with a significantly higher proportion of both categories in the diet during summer than winter at both study sites. The availability of invertebrate prey items also varied with season, and for most taxa, frequency of oc-currence was significantly higher in summer than winter. In contrast, the frequency of occurrence of seeds and bulbs (Cyperus bulbosus) varied only slightly with season. Seasonal changes in food availability were reflected by variation in dietary composition; however, relative proportions of some dietary items differed from their proportional availability. Therefore, bilbies were considered to be qualitatively opportunistic; selecting more invertebrates when their apparent availability increased, but continually exploiting the available seeds and bulbs. Additionally, although bilbies appeared to have some preferences for particular food items, several food items were selected almost randomly, and therefore bilbies were also considered to be dietary generalists. Such an opportunistic feeding strategy is advantageous to an arid-zone species as it permits the continuous exploitation of food resources that are unpredictable in their availability both spatially and temporally.


1992 ◽  
Vol 13 (3) ◽  
pp. 275-282 ◽  
Author(s):  
Gad Perry ◽  
Michael Brandeis

AbstractWe examined stomach contents of 77 specimens of Ptyodactylus hasselquistii guttatus (Lacertilia: Gekkonidae) from three locations in Israel. Juveniles took smaller and softer prey items than adults. Males had relatively larger bodies and heads and took fewer, larger and more diverse prey items than did females. Composition of stomach contents varied with collection locality and season, suggesting opportunism. Most of the prey items were small. All 324 food items were invertebrates (65.3% Insecta, 23.8% Arachnida, and 10.9% of other classes). A large proportion of food items were strict ground dwellers, suggesting frequent hunting trips to the ground.


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.


1975 ◽  
Vol 32 (10) ◽  
pp. 1799-1804 ◽  
Author(s):  
Donald S. Cherry ◽  
Rufus K. Guthrie

During early stages of succession in a new impoundment, fish species that could assimilate the readily available food resources, i.e. carp (Cyprinus carpio) and flat bullhead (Ictalurus platycephalus) were initially favored in numbers and weight. Detrital feeders or omnivores represented by carp and the flat bullhead comprised a majority of the numbers (56%) and weight (65%) of the 25 species captured during a 2-yr period. Numbers of the major fish groups captured decreased from 1971 to 1972, while the weight per species increased.On a volumetric basis, detritus and detritus-associated invertebrates (coleopterans and dipterans), were the major food items consumed by carp and catfish. Relative abundance of animal food items, in terms of frequency of occurrence and percentage of stomach contents, was greater at warmer water temperatures. In comparison to other species, catfish contained the greatest diversity of food items during warmer months and consumed larger quantities of detritus in the winter. Fish groups that constituted a smaller biomass, such as centrarchids, were generally insectivorous or fed upon cladocerans and copepods, while adult basses (Micropterus salmoides and M. coosae) and chain pickerel (Esox niger) were piscivorous.


2016 ◽  
Vol 43 (2) ◽  
pp. 213-220
Author(s):  
Kaniz Fatema ◽  
Wan Maznah Wan Omar ◽  
Mansor Mat Isa

This study was conducted in Merbok estuary, Kedah, Malaysia during January to December 2011 to assess monthly and seasonal variation in food items in the stomach of Chelon subviridis and Valamugil buchanani. A total of 341 fish samples (225 for Chelon subviridis and 116 for Valamugil buchanani) were collected from upper zone (Lalang and Sameling Rivers) of Merbok estuary. Among the stomach contents plant materials, diatom, cyanobacteria and detritus were the main food items in both fish species. In both fishes the highest numbers of food items were found in the month of November. Chelon subviridis consumed plant materials 65.84% by number and 8.55% by frequency of occurrence in the dry season whereas 66.25% by number and 9.73% by frequency of occurrence in the wet season. On the other hand, Valamugil buchanani consumed plant materials 59.54% by number and 12.28% by frequency of occurrence in the dry season whereas 72.89% by number and 11.96% by frequency of occurrence in the wet season respectively. Monthly variations of diatom as food item between C. subviridis and V. buchanani were found to be statistically significant (p<0.05). Both of the fish species consumed more food (by numerical method) in wet season than dry season.Bangladesh J. Zool. 43(2): 213-220, 2015


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