Variation in stomach contents of the gecko Ptyodactylus hasselquistii guttatus in relation to sex, age, season and locality

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):  
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.


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.


2012 ◽  
Vol 72 (2) ◽  
pp. 267-274 ◽  
Author(s):  
R. Mazzoni ◽  
PS. Marques ◽  
CF. Rezende ◽  
R. Iglesias-Rios

Spatio-temporal changes in the diet, niche breadth and niche overlap of two species of Characidium from three different sites along a Neotropical coastal stream were studied during a dry and rainy season. Seasonal changes were restricted to the occurrence of plant items in the stomach contents. The relative importance of food items in the diet of both species varied across sites, but Diptera, Ephemeroptera, Simuliidae, Trichoptera and Coleoptera larvae were always the main prey items. Contrary to the expected pattern, values of the niche breadth were higher at the site where Characidium species co-existed and niche overlapped at this site indicated 52% (p = 0.52) of feeding overlap.


1973 ◽  
Vol 21 (3) ◽  
pp. 391 ◽  
Author(s):  
BJ Coman

Stomach contents were examined for 1229 foxes collected in Victoria during 1968-70. Of these, 967 stomachs contained measurable quantities of food. The fox appears to have a very wide dietary range but is predominantly carnivorous. The main food items encountered were rabbits, sheep carrion, and mice. Lesser amounts of native mammals, birds, cold-blooded vertebrates, invertebrates, and plant material were encountered. For many foods, particularly insects, the intake was markedly seasonal. Regional differences in diet were also apparent. Much of the variation in intake of particular foods over time and between regions was explicable in terms of changing availabilities of these foods.


2001 ◽  
Vol 61 (1) ◽  
pp. 55-61 ◽  
Author(s):  
A. L. V. ANDRADE ◽  
M. C. PINEDO ◽  
A. S. BARRETO

The gastrointestinal tract of 14 false killer whales, 6 males and 8 females, stranded in June 1995 in southern Brazil, with total standard lengths from 338 to 507 cm, were analysed for endoparasites and food items. A pregnant female had a male foetus of 77.5 cm. Parasites were found in all 14 false killer whales. The nematode Anisakis simplex (Rudolphi, 1809) was found in the stomach of 57% of the animals and the acanthocephalan Bolbosoma capitatum (Linstow, 1889) Porta, 1908 was present in the intestine of all specimens and showed densities up to 600 m-1. An unidentified cestode (Tethrabothridae) was found also in the intestines of 14% of the individuals. The high infections of B. capitatum and A. simplex were not directly related with the cause of death. In the stomachs of four females, beaks of at least eight specimens of the oceanic and epipelagic species Ommastrephes bartramii (Lesueur, 1821) were found, with mantle lengths ranging from 189.8 to 360.9 mm. The distribution of O. bartramii in the coast of Rio Grande do Sul is consistent with false killer whales feeding in continental shelf waters.


2018 ◽  
Vol 10 (10) ◽  
pp. 12382-12388 ◽  
Author(s):  
Syed Asrafuzzaman ◽  
Susmita Mahapatra ◽  
Jasmin Rout ◽  
Gunanidhi Sahoo

Anuran tadpoles are gregarious predators capable of differentiating food items among diverse types of prey via varied feeding and oral structures.  Tadpoles were collected from different study sites in three districts of northern Odisha during three consecutive rainy seasons (from July–October of 2015–2017).  After morphometric measurements (total length and body length), the stomach contents of 75 tadpoles belonging to five different anuran species (Duttaphrynus melanostictus, Euphlyctis cyanophlyctis, Fejervarya orissaensis, Polypedates maculatus and Microhyla ornata) belonging to four families namely Bufonidae, Dicroglossidae, Rhacophoridae and Microhylidae were examined.  The food spectrum of tadpoles included mostly detritus, followed by phytoplankton (represented by 5 classes and 54 genera).  Such studies contribute to the understanding of the natural diets of these anuran species that can assist in developing management strategies for them.  Aquatic habitats must be conserved and maintained so that conservation of anurans can be ensured.


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.


2015 ◽  
Vol 72 (5) ◽  
pp. 1359-1369 ◽  
Author(s):  
Michael J. Miller ◽  
Jeff Dubosc ◽  
Elodie Vourey ◽  
Katsumi Tsukamoto ◽  
Valerie Allain

Abstract Leptocephali, the larvae of eels, grow to large sizes and are widely distributed in tropical and subtropical oceans. Their role in oceanic food webs is poorly known because they are rarely reported as food items in fish stomach content studies. Data from 13 years of research on the trophic dynamics of Pacific Ocean predatory fish indicate that among 8746 fish of 76 species/taxa (33 families) that had been feeding, only 16 fish of 6 species had remains of 34 leptocephali in their stomachs. Only 0.013% of the 256 308 total prey items were leptocephalus larvae, and 0.03% of the total prey items were juvenile or adult eels (mostly snipe eels: Nemichthyidae). There were 10 fish of 2 species of lancetfish (Alepisaurus spp., n = 152), 2 rainbow runners (Elagatis bipinnulata, n = 222), and 2 yellowfin tuna (Thunnus albacares, n = 3103) that had leptocephali in their stomach contents, but all except one T. albacares (contained 15 leptocephali) had each eaten ≤3 leptocephali. A swallower, Pseudoscopelus sp., and a frigate tuna, Auxis thazard, had eaten single leptocephali. Twenty-eight bigeye tuna, Thunnus obesus, had eaten 76 juvenile/adult nemichthyid or serrivomerid eels. A literature survey found that only 15 out of 75 examined publications listed leptocephali in the stomach contents of a total of 6 species out of ∼ 42 300 predatory fish of 40 species. The transparency of leptocephali and their apparent mimicry of gelatinous zooplankton could contribute to lower rates of predation. Their soft bodies likely digest rapidly, so although this study and existing literature indicate that leptocephali sometimes contribute to predatory fish diets, particularly for fish that do not exclude gelatinous prey types, and fish with low digestion rates in their stomachs such as lancetfish, their levels of contribution to fish diets and the impacts of predators on eel recruitment remain uncertain.


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.


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