Diet and prey selection dynamics of Cancer polyodon in three different habitat types in Tongoy Bay, Chile

2004 ◽  
Vol 84 (4) ◽  
pp. 751-756 ◽  
Author(s):  
Rafael I. León ◽  
Wolfgang B. Stotz
Keyword(s):  
Prey Species ◽  
Prey Availability ◽  
Prey Selection ◽  
Feeding Habits ◽  
Habitat Types ◽  
Important Prey ◽  
Selection Dynamics ◽  
Argopecten Purpuratus ◽  
Sea Grass ◽  
Main Factors

Feeding dynamics of Cancer polyodon was studied, by comparing the diets of three size-classes of the crab to environmental abundance of prey species in three habitats in Tongoy Bay, Chile (30°S). In the sea grass and sand–gravel habitats cannibalism was observed, the small C. polydon being actively selected as the main prey in spite of their lower abundance compared with other crustaceans. In the mud habitat the scallop Argopecten purpuratus was the most important prey, being actively selected although occurring at low relative abundance. Cancer polyodon showed plasticity in feeding habits, adapting to differential prey availability, but always selecting certain species independently of their abundance in each habitat. Accessibility, more than the abundance of the prey, seem to be the main factors influencing prey selection.

Comparison between the feeding habits of spotted eagle ray (Aetobatus narinari) and their potential prey in the southern Gulf of Mexico

2018 ◽  
Vol 99 (3) ◽  
pp. 661-672 ◽  
Author(s):  
F. Serrano-Flores ◽  
J.C. Pérez-Jiménez ◽  
I. Méndez-Loeza ◽  
K. Bassos-Hull ◽  
M.J. Ajemian
Keyword(s):  
Gulf Of Mexico ◽  
Prey Species ◽  
Prey Availability ◽  
Feeding Habits ◽  
Small Scale ◽  
Potential Prey ◽  
Important Prey ◽  
Ecological Aspects ◽  
Southern Gulf Of Mexico ◽  
Spotted Eagle Ray

In the southern Gulf of Mexico, the spotted eagle ray (Aetobatus narinari) is the second most frequently caught batoid in small-scale fisheries off Campeche. Ecological aspects of this ray are unknown in this region, hampering the understanding of the relationship between its distribution and prey availability in the fishing area. In order to study the feeding habits of this batoid and characterize its potential prey in the study area, stomachs and intestines of 154 specimens (68 females and 86 males) were analysed. The results indicated that A. narinari near Campeche is a specialist and selective predator that feeds mainly on gastropods (92.7% IRI), with no significant differences in the diet found between sexes, size groups, or between stomach and intestine contents. In addition, the results indicated that the most important prey species in the diet were among the most common benthic species in three of the four sampling transects positioned in or adjacent to fishing areas for rays. These most important prey species were Strombus pugilis (53.33% IRI) and Americoliva reticularis (25.6% IRI). Other prey species included Lobatus costatus (5.6% IRI) and Petrochirus diogenes (3.6% IRI). This study suggests that this widely distributed ray species feeds in Campeche's coastal waters and that the study of its potential prey increases the understanding of ecological aspects of the species, which emphasizes the added importance of monitoring fishery impacts on prey species (e.g. the conch fishery off Campeche) to help support integrated assessment and management of fisheries.

Intrapopulation variation in the diet of franciscana dolphin (Pontoporia blainvillei) off southern Brazil

2021 ◽  
pp. 1-17
Author(s):  
Manuela Bassoi ◽  
Eduardo R. Secchi ◽  
Daniel Danilewicz ◽  
Ignacio B. Moreno ◽  
Roberta A. Santos ◽  
...  
Keyword(s):  
Sexual Maturity ◽  
Linear Models ◽  
Prey Species ◽  
Prey Availability ◽  
Prey Selection ◽  
Feeding Habits ◽  
Stomach Contents ◽  
Brazilian Coast ◽  
Pontoporia Blainvillei ◽  
Franciscana Dolphin

Abstract The franciscana dolphin (Pontoporia blainvillei) is a coastal dolphin endemic to the western South Atlantic Ocean. The dolphin is listed as vulnerable in the IUCN Red List, with incidental catches in gillnet fisheries the greatest conservation concern for this species. Insights into the feeding habits of this dolphin are essential to understand its distribution, movements and use of habitat, which are fundamental for effective management of the species. The feeding habits of franciscana dolphins were investigated from analyses of stomach contents of animals incidentally caught by two fishing operations from southern and northern regions of the southern Brazilian coast. In this study we investigate the existence of intrapopulation (sexual maturity and sex-related) variation in the diet of the franciscana dolphin, evaluating the spatial (northern and southern geographic areas) and seasonal influences. The analyses were based on Linear and Generalized Linear Models (LM and GLM). The majority of identified prey species were bottom-dwelling teleosts and the squid Doryteuthis sanpaulensis. The most important prey differed spatially and seasonally between northern and southern regions of the study area, and our results revealed significant differences between sexes and sexual maturity stages, mainly related to prey species sizes. This variation might indicate differences in prey selection, availability or habitat use patterns among these groups. In any case, these dietary differences are likely to minimize intraspecific competition for food resources, and/or indicate spatio-temporal variation in prey availability.

scholarly journals Feeding Ecology of Short-Toed Snake-Eagle (Circaetus gallicus [Gmelin, 1788]) in the Montados of Iberian Peninsula

2020 ◽  
Vol 28 (2) ◽  
pp. 155-179
Author(s):  
Nuno Onofre ◽  
Luís Sampaio
Keyword(s):  
Relative Abundance ◽  
Diet Composition ◽  
Prey Species ◽  
Prey Selection ◽  
Prey Type ◽  
Generalist Predator ◽  
Important Prey ◽  
Psammodromus Algirus ◽  
Circaetus Gallicus ◽  
Water Snakes

The diet of Short-toed Snake-eagle (Circaetus gallicus) during the breeding season in an area dominated by cork and holm oak parkland forests (Montados) was analyzed in this study. As expected, results showed that snakes are the dominant prey in the diet of this eagle, comprising up to 92.5% of the identified items, if potential secondary prey species were excluded. The Montpellier Snake (Malpolon monspessulanus) was the most consumed one (42.2%), followed by the Ladder Snake (Zamenis scalaris) (28.0%), and the water snakes (Natrix spp.) (14.2%). According to the same criteria, lizards (mainly Psammodromus algirus) and mammals represent between 4.8 and 2.2%, respectively. Other animals such as pond turtle and amphibians are irregular prey (<1%), and no bird remains were found at all. Short-toed Snake-eagle is usually referred as a stenophagic predator where snakes are by far its most important prey type, and where within this taxonomic group it behaves as a generalist predator. In this study this premise was then tested comparing the relative abundance of the snake species with their proportion in the diet composition of the eagle in order to know whether or not prey selection exists with regard to the species of snakes in this region. Results point to a quite plausible "preference" for the Ladder Snake and an "avoidance" for the smooth snakes group (Macroprotodon brevis/Coronella girondica), and possibly for the Horseshoe Whip (Hemorrhois hippocrepis). The avoidance to the Horseshoe Whip must be indirect and habitat related, while in relation to the two smooth snakes it may be due in large extend to its small size, in particular.

scholarly journals Diet of Ameerega braccata (Steindachner, 1864) (Anura: Dendrobatidae) from Chapada dos Guimarães and Cuiabá, Mato Grosso State, Brazil

2011 ◽  
Vol 71 (1) ◽  
pp. 189-196 ◽  
Author(s):  
LR. Forti ◽  
ASO. Tissiani ◽  
T. Mott ◽  
C Strüssmann
Keyword(s):  
Body Size ◽  
Niche Breadth ◽  
Prey Availability ◽  
Feeding Habits ◽  
Close Association ◽  
Mato Grosso ◽  
Important Prey ◽  
Phylogenetic Perspective ◽  
Toxic Alkaloids ◽  
Two Populations

The understanding of feeding habits is important for anurans in general, both from an ecological and a phylogenetic perspective. For diurnal poison frogs belonging to the Dendrobatidae family, diet aspects play a crucial role in their defense and survival. Herein, we investigated feeding habits, foraging behaviour, and overall effects of habitat, sex, and body size on the diet of individuals of Ameerega braccata, a poorly known dendrobatid species. Specimens were observed and collected in the type-locality, Chapada dos Guimarães, and in the neighbouring municipality of Cuiabá, both in the State of Mato Grosso, Midwestern Brazil. The most important prey categories for A. braccata were Formicidae, Isoptera, and Acari, whose representatives were caught during active foraging. Individuals from Chapada dos Guimarães population consumed more Acari but fewer Isoptera than individuals from Cuiabá. Despite this, niche breadth values were narrow and similar for the two populations. Individuals from two distinct habitats (campo sujo and cerrado stricto sensu) showed differences in their diet, probably as an effect of differential prey availability. Females consumed more Isoptera than males. The number of prey categories used as food was not influenced by the variation of body size of the target species. However, the abundance and the volume of consumed Acari were statistically correlated with body size. The main results suggest that Ameerega braccata has a narrow niche breadth, as well as a specialised diet in ants, termites, and mites, which reinforces the hypotheses of close association between Acari consumption and the presence of skin toxic alkaloids, already found in other species of Dendrobatidae. Although differences in prey consumption between sexes are uncommon among poisonous frogs, differences in the diet composition between age classes, which probably reduce intraspecific competition, are frequently reported.

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.

scholarly journals Piscivory by Hoplias aff. malabaricus (Bloch, 1794): a question of prey availability?

2013 ◽  
Vol 25 (1) ◽  
pp. 68-78 ◽  
Author(s):  
Ana Karla Araujo Montenegro ◽  
Ana Carolina Brito Vieira ◽  
Maria Marcolina Lima Cardoso ◽  
Jane Enisa Ribeiro Torelli de Souza ◽  
Maria Cristina Crispim
Keyword(s):  
Environmental Factors ◽  
Food Preference ◽  
Prey Availability ◽  
Feeding Habits ◽  
Food Habit ◽  
Spearman Correlation ◽  
Reservoir Volume ◽  
Main Factors ◽  
Selection Of Species ◽  
Selection Of

AIM: In order to understand the factors which influence the predatory activity of the Hoplias aff. malabaricus, the present study evaluated feeding habits of this species and its relation to prey availability, in addition to environmental variables. METHODS: Six samplings were conducted in the Taperoá II reservoir, semi-arid of Paraíba state, Brazil, between October 2005 and October 2006. Measures were taken: rainfall, the reservoir volume, transparency, dissolved oxygen, pH, temperature, nitrate, nitrite, ammonia and phosphate. The activity, diet and feeding habits of H. aff. Malabaricus, from the method of frequency of occurrence of food items and point methods, conjugates in IAI (Alimentary Index). Spearman correlation analysis, a glm and CCA were performed between biotic and abiotic variables, and we used the CPUE as a measure of fish abundance. RESULTS: Eleven taxa of fish were recorded, four of which were predated by adult "trahira". Insects and other items were also common in the stomachs of juveniles. According to statistical analysis, it was observed that the highest consumption of cichlids was correlated with its increase in CPUE in the environment, while no relationship was observed for A. bimaculatus, C. bimaculatum and S. notonota abundances. The environmental factors as nutrients, transparency and water volumn were related to selection of species by trahira. CONCLUSIONS: Intrinsic characteristics of preys as swimming speed, food habit and the food preference of the predator possibly be the main factors to selection of species. Other mechanisms as heterogeneity of habitat and environmental factors can also influence the consumption of prey by trahira

Diet composition and prey selection in the lizard Lacerta monticola

1991 ◽  
Vol 69 (7) ◽  
pp. 1728-1735 ◽  
Author(s):  
Valentin Pérez-Mellado ◽  
Dirk Bauwens ◽  
Martin Gil ◽  
Fátima Guerrero ◽  
Miguel Lizana ◽  
...  
Keyword(s):  
Relative Abundance ◽  
Diet Composition ◽  
Prey Availability ◽  
Prey Selection ◽  
Selection Models ◽  
Important Prey ◽  
Activity Season ◽  
Individual Prey

We studied diet composition and prey selection in the lizard Lacerta monticola throughout its activity season. The most important prey groups in terms of numbers were Coleoptera, Diptera, Formicidae, and Araneae. Comparison of diet composition in the adult lizards with estimates of prey availability indicated that lizards exhibited precisely defined patterns of prey selection. Electivities were negative for prey < 3 mm in length and generally positive for larger prey, despite the higher relative abundance of the former group in the environment. Electivity scores for individual prey taxa were positively correlated with their length, and lizards preferentially consumed larger individuals belonging to the taxa containing smaller animals. Relative availability of the four major prey taxa fluctuated considerably throughout the year. In spite of these changes, monthly rates of consumption of Araneae and Diptera remained almost constant. Variations in monthly electivity scores were negatively correlated with relative availability of three (Coleoptera, Diptera, and Araneae) of the four major prey taxa. These results fit the predictions of prey-selection models based on nutrient constraints.

scholarly journals Dieta del pez chile lucio Synodus scituliceps (Aulopiformes: Synodontidae) en la Costa Este del Golfo de California, México

2020 ◽  
Vol 54 (3) ◽  
pp. 319
Author(s):  
Jesús Rodríguez-Romero ◽  
Juana López-Martínez ◽  
Ma. Ruth Ochoa Díaz ◽  
Eloísa Herrera-Valdivia
Keyword(s):  
Gulf Of California ◽  
Prey Species ◽  
Feeding Habits ◽  
Eastern Coast ◽  
Paralichthys Californicus ◽  
Important Prey ◽  
Content Analyses ◽  
Benthic Fishes ◽  
Soft Bottoms ◽  
By Catch

This study provides information on feeding habits of the lizardfish Synodus scituliceps, one of the most abundant and frequent species in shrimp by-catch in the demersal area in the eastern coast of the Gulf of California, Mexico. Stomach content analyses were performed on 114 organisms caught from August 2004 to March 2005, and Levin's index was applied. The most important prey species were benthic fishes: Eucinostomus currani, Opisthonema libertate, Synodus lucioceps and Paralichthys californicus. According to the Levin’s index (Bi = 0.39), S. scituliceps is a piscivorous specialist predator in soft bottoms, with similar diet in juveniles and adults.

scholarly journals Population- and individual-level prey selection by a solitary predator as determined with two estimates of prey availability

2016 ◽  
Vol 94 (4) ◽  
pp. 275-282 ◽  
Author(s):  
L. Mark Elbroch ◽  
Patrick E. Lendrum ◽  
Hugh Robinson ◽  
Howard B. Quigley
Keyword(s):  
Prey Species ◽  
Puma Concolor ◽  
Prey Availability ◽  
Prey Selection ◽  
Population Level ◽  
Simple Calculation ◽  
Individual Level ◽  
Dietary Niche ◽  
Two Measures ◽  
The Mean

Prey selection is exhibited by predator populations that kill a prey species disproportionate to its availability, or alternatively, individual predators that select prey disproportionate to the mean selection exhibited by their populations. Prey selection is a simple calculation when one can determine prey availability; however, measuring prey availability is challenging. We compared population- and individual-level prey selection as determined with two measures of prey availability for five ungulate species killed by pumas (Puma concolor (L., 1771)) in the Southern Yellowstone Ecosystem, USA: (1) annual prey counts and (2) total prey killed by marked pumas. We also tested whether individual pumas in the population exhibited a narrower dietary niche breadth compared with their population as a whole. The two methods yielded different estimates of prey availability and highlighted the need to consciously match prey availability estimates with appropriate ecological questions. Prey counts may have overestimated elk (Cervus canadensis (Erxleben, 1777)) abundance and underestimated deer abundance, whereas predation data may have better captured the influence of prey size on puma-specific prey vulnerability and availability. Prey counts were the more appropriate metric for analyzing population-level prey selection or differences in interspecific foraging, whereas total prey killed was the more appropriate metric for intraspecific comparisons.

scholarly journals Diet of the Deep-Sea Shark Galeus melastomus Rafinesque, 1810, in the Mediterranean Sea: What We Know and What We Should Know

2021 ◽  
Vol 13 (7) ◽  
pp. 3962
Author(s):  
Claudio D’Iglio ◽  
Serena Savoca ◽  
Paola Rinelli ◽  
Nunziacarla Spanò ◽  
Gioele Capillo
Keyword(s):  
Mediterranean Sea ◽  
Prey Availability ◽  
Trophic Position ◽  
Feeding Habits ◽  
Ontogenetic Development ◽  
Central Mediterranean ◽  
Western Basin ◽  
Important Prey ◽  
Environment Adaptation ◽  
The Mediterranean

We reviewed literature on the diet of the Galeus melastomus Rafinesque, 1810, from the Mediterranean Sea. Specific keywords (“Galeus melastomus diet”, “feeding habits”, “trophic position”, “biology”, “deep environment adaptation”) in the principal data sources, such as Web of Science, PubMed, and Google Scholar were used. Seventeen studies conducted on the diet and trophic position of G. melastomus have been considered for Mediterranean Sea regions. The feeding habits have been analyzed in many areas of the western basin; instead, for the Tyrrhenian, Adriatic, and central Mediterranean Seas, information is outdated and fragmentary. In all investigated sub areas, the data showed that G. melastomus is an opportunistic demersal supra benthic predator, benthic feeder, and scavenger, that adapts its diet to the seasonal and geographical fluctuations of the prey availability. It occupies a generalist niche showing individual specialization. In all reviewed Mediterranean sub areas, the most important prey groups were crustaceans, cephalopods, and teleost fishes. Taxa percentage in its diet composition can vary depending on different habitats with ontogenetic development of individuals, depth (that is correlated with the ontogenetic development), seasonal availability, and distribution of different prey groups. Widening knowledge of G. melastomus feeding habits is a fundamental tool for better understand meso and bathy-pelagic ecosystems.

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