Diet of the Bronze Skink Eutropis macularius (Reptilia: Squamata: Scincidae) from Thua Thien Hue Province, Central Vietnam

2020 ◽  
Vol 27 (4) ◽  
pp. 209-216
Author(s):  
Chung D. Ngo ◽  
Phuong L. T. Le ◽  
Huy D. Nguyen ◽  
Phong B. Truong ◽  
Nghiep T. Hoang ◽  
...  
Keyword(s):  
Limiting Factors ◽  
Insect Larvae ◽  
Plant Materials ◽  
Important Prey ◽  
Central Vietnam ◽  
Mouth Width ◽  
Index Of Relative Importance ◽  
Positive Correlations ◽  
Prey Length ◽  
Prey Items

In this study, we examined the diet of 149 males and 147 females of Eutropis macularius from Thua Thien Hue Province, central Vietnam using a nonlethal stomach-flushing technique. The prey items of E. macularius composed of Araneae, Insecta (Blattodea, Coleoptera, Hymenoptera, Isoptera, Odonata, and Orthoptera), Mollusca (Philomycidae), and plant materials. The most important prey items were insect larvae, hymenopterans (including ants), grasshoppers, and termites, for both sexes in three populations. Plant materials were also found in the stomach of E. macularius with an index of relative importance of 7.19%, suggesting that E. macularius is an omnivorous species. However, the dominant prey categories of E. macularius were insects, including insect larvae, hymenopterans, grasshoppers, and termites, with many small, sedentary, clumped prey items. Simpson’s heterogeneity index of skinks from three populations from Bach Ma National Park as well as from Aluoi and Huong Tra districts were 10.07, 7.85, 3.94, respectively. Eutropis macularius showed significant positive correlations between mouth width (MW) and prey width (P = 0.001) and between MW and prey volume (P 0.0001). There are significant positive correlations between snout-vent length (SVL) and prey sizes consumed: between SVL and prey length, P 0.0001; SVL and prey width, P 0.0001; and between SVL and prey volume, P 0.0001. These results indicated that SVL and MW are the limiting factors on the size of prey consumed in this skink.

Striped marlin (Kajikia audax) diet variability off Cabo San Lucas, B.C.S., Mexico during El Niño–La Niña events

2017 ◽  
Vol 98 (6) ◽  
pp. 1513-1524 ◽  
Author(s):  
Sofía Ortega Garcia ◽  
Dana I. Arizmendi-Rodríguez ◽  
Marcela S. Zúñiga-Flores
Keyword(s):  
Annual Variation ◽  
Stomach Contents ◽  
Diet Breadth ◽  
Dosidicus Gigas ◽  
Important Prey ◽  
Jumbo Squid ◽  
Diet Variability ◽  
Analysis Of Similarity ◽  
Index Of Relative Importance ◽  
Prey Items

The stomach contents of 1261 striped marlins caught from 2007 to 2010 by the sport-fishing fleet of Cabo San Lucas, Baja California Sur, Mexico, were analysed, taking into account sea surface temperatures estimated using satellite images of the study area and the Oceanic Niño Index (ONI). The analysis allowed the identification of three anomalously cold periods during 2007, 2008 and 2010 and a warm period in 2009. The stomach content results showed 89 different prey items eaten during the study period. Of the specimens captured, 868 (69%) stomachs contained food items. The most important prey items were cephalopods (Dosidicus gigas and Argonauta spp.) and fish (Scomber japonicus, Selar crumenophthalmus and Sardinops caeruleus). Despite having a broad trophic spectrum, the striped marlin was classified as a specialist consumer, with Bi = 0.03. Based on the diet breadth value and the prey-specific index of relative importance (PSIRI), the jumbo squid, D. gigas, was the main prey species, coinciding with cold periods. On the other hand, the fishes S. caeruleus and S. japonicus showed the highest PSIRI values during the 2009 warm anomalies. Analysis of similarity showed the formation of four groups in relation to PSIRI values. According to a non-metric multidimensional scaling ordination, these groups were formed with a similarity of 30% and a stress of 0.17. These results demonstrate inter-annual variation in the diet as well as in the availability and abundance of prey items.

Stomach contents of small cetaceans stranded along the Sea of Oman and Arabian Sea coasts of the Sultanate of Oman

2012 ◽  
Vol 92 (8) ◽  
pp. 1699-1710 ◽  
Author(s):  
Louisa S. Ponnampalam ◽  
Tim J.Q. Collins ◽  
Gianna Minton ◽  
Isabelle Schulz ◽  
Howard Gray ◽  
...  
Keyword(s):  
Bottlenose Dolphins ◽  
Stomach Contents ◽  
Commercial Fishing ◽  
Sultanate Of Oman ◽  
Fish Family ◽  
Important Prey ◽  
Conservation Implications ◽  
Index Of Relative Importance ◽  
Spinner Dolphins ◽  
Prey Items

This study examined the stomach contents of 11 bottlenose dolphins (Tursiops sp.), five Indo-Pacific humpback dolphins (Sousa chinensis) and two spinner dolphins (Stenella longirostris) that were found stranded along the Omani coastline. Across the three species examined, a total of 4796 fish otoliths and 214 cephalopod beaks were found, representing at least 33 species in 22 families. Prey item importance was calculated using the percentage by number and percentage by frequency of occurrence methods, and a modified index of relative importance. The fish families Apogonidae, Carangidae and Scombridae were the most numerically important prey of the bottlenose dolphins. Sciaenidae was the most numerically important fish family for the Indo-Pacific humpback dolphins. The myctophid Benthosema pterotum formed the majority of the prey items of spinner dolphins. Cephalopod remains found in the stomach samples were represented by the families Sepiidae, Loliginidae and Onychoteuthidae. The known depth distribution of prey items of bottlenose dolphins indicated that the animals fed in a wide variety of habitats. Indo-Pacific humpback dolphin prey items indicated feeding in shallow coastal areas. Spinner dolphins appear to have exploited the upper 200 m of the water column for food, where their vertically migrating mesopelagic prey are found at night. Most prey species found in the stomach contents do not appear to be of current commercial importance in Oman. However, the findings here indicated that all three species of dolphins were feeding in areas where artisanal and/or commercial fishing occurs and has conservation implications.

Trophic ecology of large pelagic fish in the Saint Peter and Saint Paul Archipelago, Brazil

2019 ◽  
Vol 70 (10) ◽  
pp. 1402 ◽  
Author(s):  
F. V. Albuquerque ◽  
A. F. Navia ◽  
T. Vaske ◽  
O. Crespo ◽  
F. H. V. Hazin
Keyword(s):  
Trophic Ecology ◽  
Feeding Habits ◽  
Saint Paul ◽  
Pelagic Fish ◽  
Trophic Niche ◽  
Trophic Relationships ◽  
Main Prey ◽  
Important Prey ◽  
Saint Peter ◽  
Prey Items

Trophic relationships of large pelagic predators can determine the structure and dynamics of oceanic food webs. The feeding habits and trophic ecology of five large pelagic fish (Acanthocybium solandri, Coryphaena hippurus, Elagatis bipinnulata, Thunnus albacares and Thunnus atlanticus) in the Saint Peter and Saint Paul Archipelago were evaluated to determine whether there is a trophic-niche overlap or resource partitioning among them. Eighty prey items found in 1528 stomachs were identified and grouped into Cephalopoda, Cnidaria, Crustacea, Gastropoda, Teleostei and Tunicata. Exocoetidae and Scombridae were the main prey in the diet of Acanthocybium solandri. In C. hippurus, Cheilopogon cyanopterus and Exocoetus volitans were the most important prey items, whereas C. cyanopterus was the main prey for T. albacares. Thunnus atlanticus consumed a great proportion of invertebrate species, with shrimps of Sergestidae family being particularly important. The gastropod Cavolinia sp. was the most important prey for E. bipinnulata. The five species had a high trophic specialisation and a high trophic level (>4.4), whereas most dietary overlaps were consistently low. The most important factor for diet dissimilarity was the consumption of Exocoetidade. All species were classified as top predators with varied diets, indicating their structural and functional importance in the food web of the Archipelago.

Population diet variation and individual specialization in the poison toad, Melanophryniscus rubriventris (Vellard, 1947)

2011 ◽  
Vol 32 (2) ◽  
pp. 261-265 ◽  
Author(s):  
María Fernanda Quiroga ◽  
Marcos Vaira ◽  
Maria Ines Bonansea
Keyword(s):  
Entire Range ◽  
Diet Composition ◽  
Foraging Strategies ◽  
Future Research ◽  
Individual Specialization ◽  
Generalist Species ◽  
Defensive Strategies ◽  
Important Prey ◽  
Diet Variation ◽  
Prey Items

AbstractFew studies have investigated the level of individual variation in diet composition of poisonous frogs and toads. We compare the diet composition of three populations of a poisonous toad, Melanophryniscus rubriventris, and predicted that toads within a population might be constrained to forage on particular types of alkaloid-containing prey and consequently diets among populations might not diverge from each other. Most important prey categories in the diets of the three populations consisted of the same ground-dwelling arthropods. We found evidence for individuals consuming different arrays of prey types in all populations implying that this “generalist” species is actually comprised of individuals eating different sets of the available range of prey. Formicidae, Acari, and Coleoptera were all important alkaloid-containing prey items in the diets of all populations and individuals, although there were differences in their order of importance among populations and individuals use different sets of the entire range of alkaloid-containing preys. Future research should evaluate individual diet variation in other poisonous anurans taxa given that shifts in diet composition might have important implications for understanding the consequences of alternate foraging strategies in the evolution of defensive strategies among species.

Trophic spectrum of the sailfish Istiophorus platypterus caught off Acapulco in the southern Mexican Pacific

2012 ◽  
Vol 93 (4) ◽  
pp. 1097-1104 ◽  
Author(s):  
Sandra Berenice Hernández-Aguilar ◽  
Leonardo Andrés Abitia-Cárdenas ◽  
Xchel Gabriel Moreno-Sánchez ◽  
Marcial Arellano-Martínez ◽  
Eduardo González-Rodríguez
Keyword(s):  
Prey Species ◽  
Feeding Habits ◽  
Coastal Region ◽  
Important Species ◽  
Mexican Pacific ◽  
Istiophorus Platypterus ◽  
Important Prey ◽  
Males And Females ◽  
Index Of Relative Importance ◽  
Size Interval

The sailfish Istiophorus platypterus is one of the most common billfish species in the Mexican Pacific. Information about its feeding habits in the coastal region of Acapulco, Guerrero is extremely limited. In the present study we quantified the diet of sailfish, based on captures made from March 2008 to December 2009 by the sport fishing fleet of Acapulco. We analysed a total of 561 stomachs, of which 254 contained food (45%). The size interval of examined specimens was between 101 and 212 cm postorbital length and between 15 and 47 kg total weight. In general, teleosts were the most important prey, followed by cephalopods. According to index of relative importance, the most important species in the diet were the fish Auxis thazard (63.04%) and Fistularia commersonii (6.62%), followed by the cephalopod Octopus spp. (4.58%). There were no significant differences in the diet by sex (males and females), sexual maturity (immature and mature), or by season (warm and cold seasons). In all cases the most important prey species was A. thazard. We conclude that the sailfish I. platypterus off Acapulco behaves as a specialist predator because, despite the consumption of a high number of prey items, it feeds preferentially on a reduced number of prey species that form schools, and are available and abundant in the ocean.

Shorebird–prey interactions in South Carolina coastal soft sediments

1997 ◽  
Vol 75 (2) ◽  
pp. 245-252 ◽  
Author(s):  
Louise M. Weber ◽  
Susan M. Haig
Keyword(s):  
South Carolina ◽  
Feedback Loop ◽  
Prey Density ◽  
Species Abundance ◽  
High Water ◽  
Insect Larvae ◽  
Prey Biomass ◽  
Exclosure Experiment ◽  
Positive Correlations ◽  
Simultaneous Influence

We investigated the simultaneous influence of benthic prey (primarily insect larvae, oligochaetes, and polychaetes) on spring-migrating shorebirds (Charadriiformes) and shorebirds on prey in brackish managed wetlands of South Carolina. We proposed that positive correlations between shorebird and prey densities and between prey reduction and shorebird density might result in a negative feedback loop. The loop would be characterized by shorebird redistribution over time and equalization of shorebird and prey densities (and biomass) across the site. In support of the feedback loop (i) there were positive correlations between shorebird and prey densities (and biomass) early in migration; (ii) shorebird predation was responsible for declines of 49% in prey density and 50% in prey biomass in a shorebird exclosure experiment, with shorebird density positively correlated with prey decline in open plots; (iii) there was equalization of prey biomass across the site, and relative prey species abundance appeared to become more equal. Contrary to predictions, shorebirds did not redistribute after prey reduction, and patchiness of shorebird and prey densities persisted across the site. This failure was attributed to high prey density, even at the season's end, and high water depths. There were no confounding indirect trophic-level effects.

scholarly journals Diet of the toad Rhinella icterica (Anura: Bufonidae) from Atlantic Forest Highlands of southeastern Brazil

2012 ◽  
Vol 12 (4) ◽  
pp. 258-262 ◽  
Author(s):  
Leandro Talione Sabagh ◽  
Ana Maria Paulino Telles Carvalho-e-Silva ◽  
Carlos Frederico Duarte Rocha
Keyword(s):  
Atlantic Forest ◽  
National Park ◽  
Niche Breadth ◽  
Trophic Niche ◽  
Southeastern Brazil ◽  
Important Prey ◽  
High Consumption ◽  
Low Diversity ◽  
Mouth Size ◽  
Index Of Relative Importance

In this study, we present some information of the regarding throphic niche from the anuran toad Rhinella icterica living in high altitudes above 2000 m a.s.l. from a habitat of the Atlantic Forest Biome - the Altitude Fields in the Itatiaia National Park. We found 150 prey items in toad stomachs, belonging to five prey types, as well as skin remains and some remains of plant material. The index of relative importance indicated that most important prey types were beetles and ants, these last composing 70% of the diet numerically and the trophic niche breadth (B) was 1.81. The relatively low diversity of prey types we recorded in the diet of R. icterica of Itatiaia and numerically dominated by ants suggests some preference for this item. We do not found significant relationship between the toad measurements with the preys' measurements. We concluded that R. icterica toads at the highlands of Itatiaia feeds on arthropods, mainly ants and coleopterans and that the high consumption of preys with relatively small and similar size as ants in the diet prevents an expected relationship among frog body or mouth size and prey volume and size.

Hard prey specialists or opportunistic generalists? An examination of the diet of the cownose ray, Rhinoptera bonasus

2007 ◽  
Vol 58 (1) ◽  
pp. 135 ◽  
Author(s):  
A. B. Collins ◽  
M. R. Heupel ◽  
R. E. Hueter ◽  
P. J. Motta
Keyword(s):  
Feeding Behaviour ◽  
Stomach Contents ◽  
Relative Importance ◽  
Charlotte Harbor ◽  
Severe Damage ◽  
Important Prey ◽  
Cownose Ray ◽  
Rhinoptera Bonasus ◽  
Group Feeding ◽  
Index Of Relative Importance

Atlantic cownose rays (Rhinoptera bonasus) are benthic, suction feeders whose foraging activities have been implicated in severe damage to commercial shellfish industries. With jaws highly modified for durophagy, it has been assumed that R. bonasus are crushing specialists that feed primarily upon hard molluscan prey. Stomach contents from R. bonasus caught within Florida’s Charlotte Harbor estuary between July 2003 and July 2004 were analysed using the index of relative importance (IRI) to determine most important prey types. Prey items were identified from 38 families and fell into nine distinctive groups. The three most dominant prey groups were crustaceans (%IRI = 55.31), polychaetes (%IRI = 25.20) and bivalves (%IRI = 12.58). Shoalmates had more similar diets than non-shoalmates, suggesting group feeding. Most small or softer-bodied prey consumed were relatively intact, indicating lack of prey processing and capture through suction feeding. All larger, harder-bodied prey showed evidence of crushing (fractured and broken shells). Although R. bonasus has been characterised as a hard prey specialist, these results suggest it may behave as an opportunistic generalist, modifying feeding behaviour to consume readily available prey.

scholarly journals Trophic ecology and foraging behavior of Tropidurus hispidus and Tropidurus semitaeniatus (Squamata, Tropiduridae) in a caatinga area of northeastern Brazil

2011 ◽  
Vol 101 (3) ◽  
pp. 225-232 ◽  
Author(s):  
Leonardo B. Ribeiro ◽  
Eliza M. X. Freire
Keyword(s):  
Foraging Behavior ◽  
Diet Composition ◽  
Trophic Ecology ◽  
Dry Season ◽  
Northeastern Brazil ◽  
Wet Season ◽  
Lizard Species ◽  
Important Prey ◽  
Lepidopteran Larvae ◽  
Prey Items

This study aimed to analyze the seasonal variation in diet composition and foraging behavior of Tropidurus hispidus (Spix, 1825) and T. semitaeniatus (Spix, 1825), as well as measurement of the foraging intensity (number of moves, time spent stationary, distance traveled and number of attacks on prey items) in a caatinga patch on the state of Rio Grande do Norte, Brazil. Hymenoptera/Formicidae and Isoptera predominated in the diet of both species during the dry season. Opportunistic predation on lepidopteran larvae, coleopteran larvae and adults, and orthopteran nymphs and adults occurred in the wet season; however, hymenopterans/Formicidae were the most important prey items. The number of food items was similar between lizard species in both seasons; however the overlap for number of prey was smaller in the wet season. Preys ingested by T. hispidus during the wet season were also larger than those consumed by T. semitaeniatus. Seasonal comparisons of foraging intensity between the two species differed, mainly in the wet season, when T. hispidus exhibited less movement and fewer attacks on prey, and more time spent stationary if compared to T. semitaeniatus. Although both lizards are sit-and-wait foragers, T. semitaeniatus is more active than T. hispidus. The diet and foraging behavior of T. hispidus and T. semitaeniatus overlap under limiting conditions during the dry season, and are segregative factors that may contribute to the coexistence of these species in the wet season.

Feeding habits of the sandskate Psammobatis extenta (Garman, 1913): sources of variation in dietary composition

2005 ◽  
Vol 56 (4) ◽  
pp. 395 ◽  
Author(s):  
J. Matías Braccini ◽  
Jorge E. Perez
Keyword(s):  
Feeding Habits ◽  
Seasonal Pattern ◽  
Seasonal Patterns ◽  
Dietary Composition ◽  
Important Prey ◽  
Eastern Brazil ◽  
Prey Diversity ◽  
Sources Of Variation ◽  
Males And Females ◽  
Prey Items

Understanding the variation in the diet of skates is crucial for determining their roles in marine ecosystems. The diet of 458 sandskates, Psammobatis extenta, from Puerto Quequén, Argentina was quantified to determine whether there was geographical, sexual, ontogenetic, and/or seasonal variation in dietary composition. Cumulative prey-diversity curves reached a stable level at ~30 stomachs and thus the sample size was large enough to describe the overall diet of the sandskate. The diet comprised a variety of small invertebrates, suggesting that the sandskate is a secondary consumer (trophic level of 3.5). The most important prey items were gammarids, shrimps and, to a lesser extent, polychaete worms. A significant correlation was found between the diets of sandskates from south-eastern Brazil and Puerto Quequén, suggesting that in both locations they used similar resources and would have similar ecological roles. No difference was found between the diets of males and females, but ontogenetic and seasonal patterns were detected. Small sandskates preyed largely on gammarids and shrimps but consumed fewer polychaetes and brachyurans than larger individuals. In summer and winter, the most important prey item by number was gammarids, whereas the consumption of shrimps peaked in autumn. This ontogenetic and seasonal pattern indicates that large and small sandskates are versatile predators that can shift their diets in response to prey abundance.

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