scholarly journals Seasonal variation on diet of juvenile Elops saurus Linnaeus, 1766 (Ladyfish) in the Parnaiba River Delta

2020 ◽  
Vol 32 ◽  
Author(s):  
Tatiane Araujo Santos ◽  
Thamires Souza Gonçalves ◽  
Patricia Silva do Nascimento ◽  
Cézar Augusto Freire Fernandes ◽  
Francisca Edna de Andrade Cunha
Keyword(s):  
High Frequency ◽  
Rainy Season ◽  
Stomach Contents ◽  
Dry Season ◽  
River Delta ◽  
Frequency Of Occurrence ◽  
Relative Importance ◽  
Dry Period ◽  
Food Items ◽  
Importance Index

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.

scholarly journals ANALISIS DEL CONTENIDO ESTOMACAL DEL CAMARON TITI Xiphopenaeus kroyeri (HELLER) (CRUSTACEA: NATANTIA: PENAEIDAE)

2016 ◽  
Vol 19 ◽  
Author(s):  
Martha L. Cortés ◽  
María M. Críales
Keyword(s):  
Feeding Habits ◽  
Stomach Contents ◽  
Dry Weight ◽  
Dry Season ◽  
Frequency Of Occurrence ◽  
Food Items ◽  
Size Groups ◽  
Xiphopenaeus Kroyeri ◽  
Carbohydrate Levels ◽  
Bivalve Shells

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.

scholarly journals Variation of Food items in the Stomach Contents of two Mullets, Chelon subviridis and Valamugil buchanani, from Merbok Estuary, Kedah, Malaysia

2016 ◽  
Vol 43 (2) ◽  
pp. 213-220
Author(s):  
Kaniz Fatema ◽  
Wan Maznah Wan Omar ◽  
Mansor Mat Isa
Keyword(s):  
Fish Species ◽  
Stomach Contents ◽  
Dry Season ◽  
Frequency Of Occurrence ◽  
Wet Season ◽  
Plant Materials ◽  
Food Items ◽  
Fish Samples ◽  
Merbok Estuary ◽  
Monthly Variations

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

scholarly journals Nocturnal Boundary Layer Erosion Analysis in the Amazon Using Large-Eddy Simulation during GoAmazon Project 2014/5

Atmosphere ◽  
2021 ◽  
Vol 12 (2) ◽  
pp. 240
Author(s):  
Rayonil Carneiro ◽  
Gilberto Fisch ◽  
Theomar Neves ◽  
Rosa Santos ◽  
Carlos Santos ◽  
...  
Keyword(s):  
Boundary Layer ◽  
Large Eddy Simulation ◽  
Rainy Season ◽  
Nocturnal Boundary Layer ◽  
Enso Event ◽  
Dry Season ◽  
Dry Period ◽  
Additional Energy ◽  
Eddy Simulation ◽  
Large Eddy

This study investigated the erosion of the nocturnal boundary layer (NBL) over the central Amazon using a high-resolution model of large-eddy simulation (LES) named PArallel Les Model (PALM) and observational data from Green Ocean Amazon (GoAmazon) project 2014/5. This data set was collected during four intense observation periods (IOPs) in the dry and rainy seasons in the years 2014 (considered a typical year) and 2015, during which an El Niño–Southern Oscillation (ENSO) event predominated and provoked an intense dry season. The outputs from the PALM simulations represented reasonably well the NBL erosion, and the results showed that it has different characteristics between the seasons. During the rainy season, the IOPs exhibited slow surface heating and less intense convection, which resulted in a longer erosion period, typically about 3 h after sunrise (that occurs at 06:00 local time). In contrast, dry IOPs showed more intensive surface warming with stronger convection, resulting in faster NBL erosion, about 2 h after sunrise. A conceptual model was derived to investigate the complete erosion during sunrise hours when there is a very shallow mixed layer formed close to the surface and a stable layer above. The kinematic heat flux for heating this layer during the erosion period showed that for the rainy season, the energy emitted from the surface and the entrainment was not enough to fully heat the NBL layer and erode it. Approximately 30% of additional energy was used in the system, which could come from the release of energy from biomass. The dry period of 2014 showed stronger heating, but it was also not enough, requiring approximately 6% of additional energy. However, for the 2015 dry period, which was under the influence of the ENSO event, it was shown that the released surface fluxes were sufficient to fully heat the layer. The erosion time of the NBL probably influenced the development of the convective boundary layer (CBL), wherein greater vertical development was observed in the dry season IOPs (~1500 m), while the rainy season IOPs had a shallower layer (~1200 m).

scholarly journals Feeding habits of Cocobolo Andinoacara pulcher in the cienaga Grande de Lorica, Colombia

2016 ◽  
pp. 5189-5197
Author(s):  
Charles W Olaya-Nieto ◽  
Liquey Camargo-Herrera ◽  
Vanessa Díaz-Sajonero ◽  
Fredys F Segura-Guevara
Keyword(s):  
River Basin ◽  
Stomach Content ◽  
Feeding Habits ◽  
Frequency Of Occurrence ◽  
Relative Importance ◽  
Food Groups ◽  
Total Length ◽  
Length Relationship ◽  
Importance Index ◽  
Gut Length

ABSTRACTObjective. The feeding habits of Cocobolo (Andinoacara pulcher) in the cienaga Grande de Lorica, Sinu river basin, were studied. Materials and methods. The stomach content was analyzed using the Proportion of empty stomachs, Grade of digestion, Frequency of occurrence, numerical Frequency, Gravimetry, relative importance Index (RII) and the gut length-total length relationship. Results. 39.8% of stomachs were empty, 47.1% of preys were fresh and five food groups were identified. Vegetable remains was the most frequent group (63.8%) and the prey with greatest composition in weight (33.5%), while Rest of fishes was the most abundant group (34.7%). It was observed that in low and rising waters, fishes was the most consumed prey, while that in high and falling waters the most consumed prey was vegetable remains. Vegetable remains, detritus and fishes were food groups of secondary relative importance, while Insects and Others were circumstantial or incidental groups. Conclusions. The results achieved indicate that Cocobolo is a fish with omnivores feeding habits with a preference for fishes and vegetable remains. RESUMEN Objetivo. Se estudiaron los hábitos alimentarios de Cocobolo (Andinoacara pulcher) en la ciénaga Grande de Lorica, cuenca del río Sinú, Colombia. Materiales y Métodos. El contenido estomacal se evaluó con el Coeficiente de vacuidad, Grado de llenado, Grado de digestión, Frecuencia de ocurrencia, Frecuencia numérica, Gravimetría, Índice de importancia relativa y la relación longitud intestinal- longitud total. Resultados. El 39.8% de los estómagos se encontró vacío, el 47.1% de las presas en estado fresco y se identificaron cinco grupos alimentarios. Material vegetal fue el grupo más frecuente (63.8%) y con mayor composición por peso (33.5%), mientras que Restos de peces fue el más abundante (34.7%). Se observó que en aguas bajas y en aguas ascendentes, peces fue la presa más consumida, mientras que en aguas altas y aguas descendentes, fue material vegetal. Material vegetal, detritos y restos de peces fueron grupos alimentarios de importancia relativa secundaria, mientras que insectos y otros fueron circunstanciales o incidentales. Conclusiones. Los resultados alcanzados indican que Cocobolo es un pez de hábitos alimentarios omnívoros con preferencia por peces y material vegetal.

Diet of crab-eating fox (Cerdocyon thous) in two conservation units of the Amazon rainforest, Brazil

2024 ◽  
Vol 84 ◽  
Author(s):  
F. M. Dutra-Vieira ◽  
M. S. Silva ◽  
G. S. Vieira ◽  
A. S. Carvalho ◽  
B. C. Schimming
Keyword(s):  
Dry Matter ◽  
Amazon Basin ◽  
Stomach Contents ◽  
Amazon Rainforest ◽  
Animal Origin ◽  
Mineral Matter ◽  
Frequency Of Occurrence ◽  
Conservation Units ◽  
Food Items ◽  
Cerdocyon Thous

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.

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.

scholarly journals Feeding aspects of Knodus heteresthes (Eigenmann, 1908) and Moenkhausia lepidura (Kner, 1858) (Characiformes, Characidae) in the Teles Pires and Juruena Rivers, southern Amazon

2020 ◽  
Author(s):  
E. Oliveira ◽  
A. R. A. Ignácio ◽  
W. L. Lázaro ◽  
C. C. Muniz ◽  
D. V. S. Campos ◽  
...  
Keyword(s):  
Stomach Contents ◽  
Niche Overlap ◽  
Trophic Niche ◽  
Frequency Of Occurrence ◽  
Dietary Preference ◽  
Importance Index

Abstract The composition of the diet of two species of characids (Knodus heteresthes and Moenkhausia lepidura) was evaluated in the Teles Pires and Juruena Rivers, sampled in September and October 2016. We analyzed 226 stomachs of K. heteresthes and 425 of M. lepidura. The analysis of the stomach contents was based on volumetric and frequency of occurrence methods, applying the food importance index. For the similarity of the diets between the species we calculated the niche overlap with Pianka’s index. Both species in the Juruena River have a dietary preference for arthropods (IAi > 0.95). In the Teles Pires River the diet is concentrated in three sources for both species: arthropods (IAi > 0.52), vegetables (IAi > 0.33) and fish (IAi > 0.12). The diet was dissimilar when compared to environments (ANOSIM, R ≥ 0.57, p < 0.001) with high trophic niche overlap (α > 0.97), regardless of the sampled environment. In the Teles Pires River, both species were classified as omnivorous with an insectivorous tendency and in the Juruena River the insectivorous behaviour occurs.

scholarly journals Diet of two syntopic species of Crenuchidae (Ostariophysi: Characiformes) in an Amazonian rocky stream

2017 ◽  
Vol 17 (1) ◽  
Author(s):  
Suzanne Fernandes ◽  
Rafael Pereira Leitão ◽  
Eurizângela Pereira Dary ◽  
Ana Isabel Camacho Guerreiro ◽  
Jansen Zuanon ◽  
...  
Keyword(s):  
Fish Species ◽  
Stomach Contents ◽  
Relative Volume ◽  
Diet Overlap ◽  
Frequency Of Occurrence ◽  
Food Items ◽  
Taxonomic Level ◽  
Genus Level ◽  
The Family ◽  
Feeding Plasticity

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.

scholarly journals Sexual behavior of 'morada nova' breeding sheep under semi-intensive rearing during the mating season in the brazilian semiarid

2017 ◽  
Vol 38 (6) ◽  
pp. 3657
Author(s):  
Luana de Fátima Damasceno dos Santos ◽  
Edgard Cavalcanti Pimenta Filho ◽  
Edilson Paes Saraiva ◽  
Dermeval Araújo Furtado ◽  
Walter Esfrain Pereira ◽  
...  
Keyword(s):  
Sexual Behavior ◽  
Sexual Behaviors ◽  
Rainy Season ◽  
Dry Season ◽  
Dry Period ◽  
Brazilian Semiarid ◽  
Intensive Rearing ◽  
Execution Frequency ◽  
Dry And Rainy Seasons ◽  
Intensive System

This study aimed to evaluate the sexual behavior of 'Morada Nova' breeding sheep reared in the Brazilian semi-arid during dry and rainy seasons in a semi-intensive system. The behavioral data were gathered from 4 rams and 114 ewes, among which 55 during the rainy season and the other 59 females in the dry season. The behavioral observations were conducted from 6 am to 5 pm, during both periods. The observations were carried out continuously and split into 'event' (execution frequency) and 'state' (execution time). During the rainy season, the breeding sheep showed the most efficient sexual behavior, with a shorter reaction time (RT) and less frequent mount attempts (MA), being of 122 sec and 2.97, respectively. However, throughout the dry period, some sexual behaviors such as sniffing the urogenital of females (SUF), penis exposure (EXP), head tossing (HT), and courting of females (FC) became more frequent, mainly in the afternoon, as with the flehmen response (FR). Male courting behavior was more evident in the rainy season during the end of the day, remaining less active during the dry period. Sexual behavior intensity in 'Morada Nova' sheep varies throughout the day, especially in the dry season.

scholarly journals Diet of the freshwater stingray Potamotrygon motoro (Chondrichthyes: Potamotrygonidae) on Marajó Island (Pará, Brazil)

2010 ◽  
Vol 70 (1) ◽  
pp. 155-162 ◽  
Author(s):  
MP. Almeida ◽  
PMO. Lins ◽  
P. Charvet-Almeida ◽  
RB. Barthem
Keyword(s):  
Stomach Contents ◽  
Relative Importance ◽  
Food Items ◽  
Freshwater Stingray ◽  
Marajó Island ◽  
Index Of Relative Importance

The stomach contents of 137 examples of Potamotrygon motoro caught in 3 locations (Muaná, Afuá and Lake Arari) on Marajó Island were analysed. The values of the Index of Relative Importance (IRI) and its respective percentage (%IRI) were calculated. The level of repletion 1 (¼ full) was the most representative for both sexes, as well as for immature and mature specimens. Most of the food items found were well-digested. The food items identification indicated the presence of 15 orders, including insects, mollusks, crustaceans, annelids and fish. Differences in diet were observed among the locations studied when comparing %IRI, crustaceans being the most preferred in Afuá, fish in Lake Arari and mollusks in Muaná.

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