scholarly journals Feeding habits of Lithobates megapoda (Anura: Ranidae), a threatened leopard frog used for human consumption, in Lake Chapala, Mexico

2021 ◽  
Vol 20 (1) ◽  
pp. 75-88
Author(s):  
José Luis Barragán-Ramírez ◽  
Benjamín Hernández ◽  
María Guadalupe Velarde-Aguilar ◽  
Oscar Pérez-Flores ◽  
José Luis Navarrete-Heredia ◽  
...  
Keyword(s):  
Trophic Ecology ◽  
Dietary Diversity ◽  
Feeding Habits ◽  
Stomach Contents ◽  
Prey Type ◽  
Leopard Frog ◽  
Human Consumption ◽  
Relative Importance ◽  
Prey Category ◽  
Lake Chapala

The Big-footed Leopard Frog (Lithobates megapoda) is a threatened and endemic species from western Mexico. This species has aquatic habits and it is distinguished by its large size, particularly by the length of its legs, reason for which it is captured for human consumption. Also, knowledge about its natural history is scarce and incomplete. In this study, we analyzed the composition of the diet of L. megapoda on the shore of Lake Chapala, the largest lake in Mexico. A total of 69 adult individuals were collected lifeless in fishing nets, during the rainy season (June-October), of which 48 had stomach contents. A total of 96 prey items were identified, which correspond to 13 prey categories. Fish constituted the most dominant prey category in the diet in terms of number, volume, frequency of occurrence, and relative importance. No significant differences were found in the consumption by prey type (aquatic or terrestrial). However, the aquatic preys had a greater relative importance and were more voluminous than the terrestrial ones. The diversity of prey categories, in terms of prey volume, indicates males may have a higher dietary diversity than females, but we not evaluated possible bias. In addition, a significant effect was found in the interaction of size (SVL) of frogs with the average of prey volume. Females (that are larger than males) consumed prey within a wide volume range and, the larger they are, more voluminous are prey. In this way it is possible that intraspecific competition for trophic resources in the environment is reduced. This study helps us understand the trophic ecology of L. megapoda, a frog species that plays an important role in the food web where it lives, as a predator feeding on aquatic and terrestrial organisms.

Invasive bullfrogs as predators in a Neotropical assemblage: What frog species do they eat?

2012 ◽  
Vol 62 (4) ◽  
pp. 397-408 ◽  
Author(s):  
Ruben A. Boelter ◽  
Igor L. Kaefer ◽  
Camila Both ◽  
Sonia Cechin
Keyword(s):  
South America ◽  
Stomach Contents ◽  
Relative Importance ◽  
Feeding Preferences ◽  
Prey Category ◽  
American Bullfrog ◽  
Important Prey ◽  
Prey Composition ◽  
Frog Species

Anurans are important prey for the American bullfrog Lithobates catesbeianus, but field assessments of its diet in the context of a local prey assemblage are lacking. We aimed to identify the frog species consumed by an invasive bullfrog population in subtropical South America, and to assess their relative importance among other types of prey. Characterization of the frog assemblage in the study area also allowed us to calculate the degree of electivity of the recorded anuran prey, in order to gain insight regarding bullfrog feeding preferences and to test if the bullfrog prey composition differed from a random sample of the assemblage. A total of 32.6% of the bullfrogs had at least one anuran in the stomach contents, and post-metamorphic anurans represented 49.1% of the relative prey importance for adult bullfrogs. Anurans were preyed on by all size classes, and constituted the volumetrically most important prey category in the diet of individuals heavier than 100 g. Cycloramphidae, Hylidae and Leiuperidae were positively selected, and Hypsiboas pulchellus and Physalaemus cuvieri were the species most often taken. We found a low occurrence of cannibalism, despite the high density of bullfrogs at the study site. Our results showed that the degree of electivity differed among bullfrog prey types, suggesting that some frog species may be preyed on in a higher proportion than their relative abundance in the assemblage. Testing the clues provided by this assemblage-level approach may lead to a better assessment of the interactions between bullfrogs and the native frog fauna.

scholarly journals Trophic ecology of Mugil liza at the southern limit of its distribution (Buenos Aires, Argentina)

2015 ◽  
Vol 63 (3) ◽  
pp. 271-277 ◽  
Author(s):  
Gustavo Thompson ◽  
Roberta Callico Fortunato ◽  
Ignacio Chiesa ◽  
Alejandra Volpedo
Keyword(s):  
Trophic Ecology ◽  
Buenos Aires ◽  
Feeding Habits ◽  
Stomach Contents ◽  
Benthic Fauna ◽  
Fine Sand ◽  
Coarse Sand ◽  
Buenos Aires Province ◽  
Southern Limit ◽  
Rates Of Growth

AbstractIn order to get to know the habitat and feeding habits of Mugil liza on the southern coast of Buenos Aires province, 65 specimens obtained at two sampling sites - the San Blas bay (SBB) and the mouth of the Quequén-Salado river (QSR) - during spring (November 2012) and summer (February 2013) were analyzed. Specimens were measured, sexed and weighed, their stomachs were removed and their stomach contents weighed and analyzed under the stereoscopic microscope. The specimens were adults, 28-49 cm in length and weighing 380-1100 g. Population growth was higher in the SBB (TW: 0.003*TL3.36), than in RQS (TW: 0.045*TL2.61). About 98% of the stomachs had some content, their repletion rate being of between 0.4 and 1.2%. About 75% of the stomachs contained very fine sand with few benthic organisms (algae, copepods, foraminifera), whereas the remaining 25% of stomachs contained coarse sand and a greater presence of benthic fauna (amphipods, bivalves, gastropods and coral organisms). The linear relationship between the weight of stomach contents and the total weight and length of the fish showed that the rates of growth (slope) were the same at both sites, but intercept values were significantly higher for San Blas bay (test parallelism; p < 0.001).

scholarly journals Feeding habits of Aspitrigla cuculus (L., 1758) (red gurnard), Lepidotrigla cavillone (Lac., 1802) (large scale gurnard) and Trigloporus lastoviza (Brunn., 1768) (rock gurnard) around Cyclades and Dodecanese Islands (E. Mediterranean)

2000 ◽  
Vol 1 (1) ◽  
pp. 91 ◽  
Author(s):  
A. TERRATS ◽  
G. PETRAKIS ◽  
C. PAPACONSTANTINOU
Keyword(s):  
Large Scale ◽  
Eastern Mediterranean ◽  
Feeding Habits ◽  
Stomach Contents ◽  
Frequency Of Occurrence ◽  
Relative Importance ◽  
Bottom Trawling ◽  
Percentage Frequency ◽  
Index Of Relative Importance

The feeding habits of the three most abundant gurnard species, red gurnard (Aspitrigla cuculus), large scale gurnard (Lepidotrigla cavillone) and rock gurnard (Trigloporus lastoviza) in the eastern Mediterranean (Dodecanese and Cyclades, Greece) are examined. The stomach contents of the gurnard specimens collected in April and September 1996 by bottom trawling were analyzed. The % frequency of occurrence, % number and % weight of prey types in the stomach contents were evaluated. By weight, Mysidacea and Decapoda dominated in the diet of the three species in both seasons, however the Index of Relative Importance, as well as the percentage frequency of occurrence varied. Rock gurnard presented the most diverse diet whereas the diet of large scale and red gurnard were more specialized. High overlap in terms of number was found between rock and large scale gurnard in May. Rock gurnard had the most divers diet in both seasons.

Diet of the amphi-Atlantic scaphopod Fissidentalium candidum in the deep waters of Campos Basin, south-eastern Brazil

2016 ◽  
Vol 97 (6) ◽  
pp. 1259-1266
Author(s):  
Renato Junqueira De Souza Dantas ◽  
Lazaro Luiz Mattos Laut ◽  
Carlos Henrique Soares Caetano
Keyword(s):  
Trophic Ecology ◽  
Inorganic Material ◽  
Dietary Diversity ◽  
Feeding Habits ◽  
High Rate ◽  
South Eastern ◽  
Deep Waters ◽  
Campos Basin ◽  
Eastern Brazil ◽  
Polymetallic Nodules

Specimens of Fissidentalium candidum collected at Campos Basin, south-eastern Brazil, had their diet investigated in order to assess its feeding habits. Benthic prey exceeded the planktonic ones as expected and Foraminifera constituted the most frequent prey taxa, comprising about 99.5% of the scaphopod diet; the remaining components included a few molluscs (gastropods, bivalves and scaphopods), a nematode, an ostracod crustacean, fish otoliths, unknown partial organisms and inorganic material (e.g. sediment grains and polymetallic nodules). Amongst the species previously studied, F. candidum stood out by presenting the highest dietary diversity (H = 3.35) and species richness (N = 118). Predator and prey dimensions were not correlated and no spatial variation was observed in the diet amongst the three collection sites in the mid-slope of Campos Basin. Generalism, high rate of rare or unimportant species and high contribution of within-phenotype component to the niche width were important features of the trophic ecology of F. candidum. Inhabiting the deep water of Campos Basin, this dentaliid obtained most of its energy from the benthic microfauna, being a specialized foram predator with moderate preference for, and moderate selection against, several species.

Diet composition and food habits of Caranx rhonchus (Carangidae) from the Gulf of Gabes (central Mediterranean)

2008 ◽  
Vol 88 (4) ◽  
pp. 831-836 ◽  
Author(s):  
Ayda Sley ◽  
Othman Jarboui ◽  
Mohamed Ghorbel ◽  
Abderrahmen Bouain
Keyword(s):  
Feeding Habits ◽  
Stomach Contents ◽  
Relative Importance ◽  
Central Mediterranean ◽  
Gulf Of Gabes ◽  
Food Category ◽  
Piscivorous Fish ◽  
Gulf Of Gabès ◽  
Wide Range ◽  
South Tunisia

From June 2004 to May 2006, 1040 Caranx rhonchus (Carangidae) ranging from 6.5 to 30.6 cm in total length (TL), fished in the Gulf of Gabes (south Tunisia, central Mediterranean), were used to investigate feeding habits of the species. This study was based mainly on the evolution of the index of relative importance (IRI) with respect to sex, fish size and season. Among 1040 stomachs examined, 595 were empty (%VI = 57.2). The vacuity index (%VI) differed significantly across months and declined slightly with season. A total of 13 species representing 12 different families belonging to four major groups: teleosts, crustaceans, molluscs and annelids, were identified in stomach contents of Caranx rhonchus.Caranx rhonchus is primarily an opportunistic piscivorous fish with a diet characterized by a wide range of species. Teleosts occurred in the majority of stomachs, with a total of the relative importance (%IRI) of 52.7%. The anchovy Engraulis encrasicolus were the most important teleost species (%IRI = 11.2), while crustaceans were the second most important food category consumed (47.1%).There were no significant differences in the diet between males and females, but significant differences were found with season and among size-classes.

scholarly journals Diet and feeding habits of Saurida tumbil (Bloch, 1795) from northern Kerala, South-west coast of India

2016 ◽  
Vol 63 (4) ◽  
Author(s):  
P. P. Manojkumar ◽  
P. P. Pavithran
Keyword(s):  
West Coast ◽  
Prey Size ◽  
Feeding Habits ◽  
Stomach Contents ◽  
Relative Importance ◽  
West Coast Of India ◽  
South West ◽  
South West Coast ◽  
Index Of Relative Importance ◽  
Maximum Similarity

Composition of the diet of greater lizardfish Saurida tumbil (Bloch, 1795), caught from northern Kerala, south-west coast of India was studied and described. The stomachs of 1981 specimens were collected between January, 2012 and June, 2014. Analysis of stomach contents based on index of relative importance (IRI) revealed that this species is exclusively piscivorous. Contrary to other benthic predators of the study area, it mainly feeds on pelagic and demersal fishes(IRI = 63.2), molluscs (IRI = 17.86), crustaceans (IRI = 18.33) and other miscellaneous items (IRI = 2.54). The diet of S. tumbil were found to be related to the seasonal availability of resources, occurrence of juveniles of certain species and on the migration of fishes from nearby places to the study area. Significant changes in prey items were observed between predator length groups, but a positive, significant relationship was recorded between prey size and predator size (p<0.05). Statistical analysis indicated a uniform representation of different diets in the stomach. Maximum similarity in diet between different food items was found in April and November.

scholarly journals FEEDING HABITS OF Lutjanus synagris (TELEOSTEI: LUTJANIDAE) IN THE AMAZON COAST OF THE NORTHEAST REGION OF BRAZIL

2021 ◽  
Vol 46 (4) ◽  
Author(s):  
Jackellynne Fernanda Farias FERNANDES ◽  
Jailza FREITAS ◽  
Yago Bruno Silveira NUNES ◽  
Rafael Santos LOBATO ◽  
Marina Bezerra FIGUEIREDO
Keyword(s):  
Feeding Habits ◽  
Stomach Contents ◽  
Food Composition ◽  
Relative Importance ◽  
Abiotic Conditions ◽  
Ecological Index ◽  
Food Items ◽  
Synthetic Materials ◽  
Spatial Differences ◽  
The Relationship

The feeding habit of lane snapper Lutjanus synagris was analyzed qualitatively and quantitatively, related to seasonality, its ontogenetic development, and the relationship between food and biotic and abiotic conditions on the Amazon Coast of Maranhão, between June 2018 and May 2019. Numerical, gravimetric, and ecological index methods were used to show the relative importance or preference of a category or food item in the diet. The food composition was studied related to the sex, size of the predator and seasonality. Of 359 stomachs sampled, 54 were empty due to regurgitation and presented a vacuity coefficient (Cv%) of 15.04%. In the analysis of diets between the sexes, it was possible to identify a greater participation of fish (30.43%) and Crabs (26.10%) for females, Shrimp (36.23%) and Organic Matter Not Identified (OMNI) (18.84%) in males. The diet showed spatial differences in length distributions. The analysis of stomach contents showed the presence synthetic materials (mesoplastics ranging from 5.0 mm to 2.5 cm) in 5.52% of the samples. The main food items found were from the Brachyura and Caridea species. The results clearly demonstrate that lane snapper prefers benthic prey, presenting a carnivorous and generalist-opportunistic habit. Its diet is also composed of demersal-pelagic species, such as Cephalopods and Teleost fish.

scholarly journals Feeding Habits of Different Fish Species in Negombo Lagoon

2019 ◽  
Vol 8 (2) ◽  
pp. 86-96
Author(s):  
Neetha Punchihewa ◽  
M.P.C. Silva
Keyword(s):  
Fish Species ◽  
Niche Breadth ◽  
Feeding Habits ◽  
Juvenile Fish ◽  
Stomach Contents ◽  
Gut Contents ◽  
Filamentous Algae ◽  
Relative Importance ◽  
Food Items ◽  
Plant Matter

To investigate the feeding habits of different fish species in Negombo lagoon, fish species were collected from Kadolkele and Liyanagemulla sites during February 2015 to July 2015 using a drag net. Collected specimens were preserved in 5% formalin. Later, the fish specimens were dissected, and stomach contents were mixed with water to make a suspension. One ml of suspension was added to the Sedgewick Rafter cell, and examined under the light microscope. The occurrence %, volume %, numbers %, and the Relative Importance Values (RIV) were calculated. The gut contents of 62 samples from 12 fish species were analyzed; 11 species were found to feed on mangroves, 10 on seagrasses, and 8 on filamentous algae. 13 food items were identified. Most of the analysed fish were categorized as omnivores and opportunistic feeders. The juvenile fish mainly feed on a combination of mangroves, seagrasses and filamentous algae. Apart from plant matter, the juvenile fish were found to feed upon Cyclops sp. and mysids. Although Hemirhamphus marginatus is an omnivore, it specially fed on mangroves, seagrasses and filamentous algae. Furthermore, H. marginatus consumed common food items in both habitats except mangroves and molluscs, and the shifting of its diet was depended on the availability of food. The broadest niche breadth was recorded by H. marginatus and the shortest niche breadth by the herbivorous fish species, Siganus vermiculatus and Liza macrolepis. Caranx sexfasciatus exhibited an ontogenetic shift in their diet. The smaller C. sexfasciatus was a carnivore and the larger individuals of the same species were herbivores.

scholarly journals Diet Composition and Trophic Level of Greater Forkbeard Phycis blennoides (Gadiform: Phycidae) from the Algerian Coast

2018 ◽  
Vol 76 (4) ◽  
pp. 135-144
Author(s):  
Zakia Alioua ◽  
Soumia Amira ◽  
Farid Derbal ◽  
Mounira Rachedi ◽  
Lamia Bahbah ◽  
...  
Keyword(s):  
Trophic Level ◽  
Diet Composition ◽  
Feeding Habits ◽  
Feeding Strategy ◽  
Stomach Contents ◽  
Relative Importance ◽  
Diverse Range ◽  
Qualitative And Quantitative ◽  
Algerian Coast ◽  
Index Of Relative Importance

Abstract The diet of the greater forkbeard Phycis blennoides (Brünnich, 1768) of the Algerian coast was studied between December 2013 and June 2015, providing information on its ecology for a better understanding of the feeding strategy. A total of 956 individuals, whose total length (TL) varied between 9.7 and 54.5 cm and weight (W) between 2.80 and 1334.11 g, were examined. The index of relative importance (%IRI), combining the three main descriptors of the presence of different ingested prey (%F, %N, %W), was used to characterize the relative importance of different food taxa. Qualitative and quantitative variations in diet were studied according to sex, size and seasons. The average annual digestive vacuity index (%V) was 5.51. It did not vary between seasons (x2cal = 5.43, x2th = 7.82, α = 5%) and size (x2cal = 2.08, x2th = 5.99, α = 5%), but was different between male (%V = 4.94) and female (%V= 12.78). Qualitative analysis of stomach contents reveals a fairly diverse range of predation with 1342 preys counted for a total weight of 462.84 g, which corresponds to an average number (AN) and weight (AW) of 3.03 and 1.04 g, respectively. This species feeds on benthic preys, composed mainly of natantia crustaceans (%IRI = 44.84) and teleost fish (%IRI = 2.61) with intraspecific preys (%IRI = 6.15). This cannibalism was frequent in specimens with a TL that exceeds 20 cm; it was even more frequent in females as well as in winter. Significant differences in feeding habits of P. blennoides occurred according to sex, fish size and between seasons. The trophic level (TROPH) was high (3.66 < TROPH < 3.97), corresponding to carnivorous character.

Investigating diet patterns of highly mobile marine predators using stomach contents, stable isotope, and fatty acid analyses

2018 ◽  
Vol 75 (5) ◽  
pp. 1583-1590 ◽  
Author(s):  
Talia Young ◽  
Jennifer Pincin ◽  
Philipp Neubauer ◽  
Sofía Ortega-García ◽  
Olaf P Jensen
Keyword(s):  
Fatty Acid ◽  
Stable Isotope ◽  
Trophic Ecology ◽  
Feeding Habits ◽  
Stomach Contents ◽  
Short Term ◽  
Predator Species ◽  
Diet Patterns ◽  
Marine Predators

Abstract Determining what animals eat is simultaneously challenging and yet also critical for ecologists, fisheries scientists, and resource managers. The tools of trophic ecology have expanded considerably in the last half century in pursuit of this goal. In this study, we combined stomach contents, stable isotope, and fatty acid analyses to investigate trophic patterns in three species of highly mobile, pelagic predators: striped marlin (Kajikia audax), blue marlin (Makaira nigricans), and common dolphinfish (Coryphaena hippurus). We were particularly interested in examining individual diet specialization among these species. We compared the short-term stomach contents with long-term diet proportions estimated from stable isotope ratios and fatty acid profiles using a Bayesian mixing model. Our results indicate that all three species feed on a mix of prey types. This work furthermore suggests that individuals of all three predator species demonstrate generalist feeding habits, with minimal differences in long-term (weeks, months) diet estimates between individuals with different short-term (hours, days) stomach contents. This novel, three-part analytical approach can elucidate complex and otherwise elusive trophic dynamics.

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