scholarly journals Diet of Bryconops alburnoides and B. caudomaculatus (Osteichthyes: Characiformes) in the region affected by Balbina Hydroelectric Dam (Amazon drainage, Brazil)

2008 ◽  
Vol 6 (2) ◽  
pp. 237-242 ◽  
Author(s):  
Cylene C. da Silva ◽  
Efrem J. G. Ferreira ◽  
Cláudia P. de Deus
Keyword(s):  
Heavy Rainfall ◽  
Amazon Basin ◽  
Relative Volume ◽  
Fish Diet ◽  
Frequency Of Occurrence ◽  
Important Data ◽  
Hydroelectric Dam ◽  
Morisita Index ◽  
Terrestrial Insects ◽  
And Behavior

The study of fish diet and its interaction with the environment provides important data on ecology and behavior, as fish face varying environmental and food availability conditions. The aim of the present study was to determine the diet of Bryconops caudomaculatus and Bryconops alburnoides, as well as to assess its seasonal variation, within the area influenced by Balbina Hydroelectric Dam (BHD), in the Uatumã River (Amazon Basin, Brazil). Collections were carried out every two months from April 2005 to February 2007, using gill nets with mesh sizes ranging from 12 to 60 mm between opposite knots. Two methods were used for determining diet: frequency of occurrence and relative volume, which were used to calculate the alimentary index (IAi). Diet similarity between species was analyzed by applying the Morisita index. Bryconops alburnoides ingested 12 items and B. caudomaculatus 10, with a 59% similarity between ingested items. Terrestrial insects for B. alburnoides and immature insects for B. caudomaculatus were the main items in their diets, and therefore, they were considered insectivorous. The seasonal composition of the diet of B. alburnoides was influenced by environmental factors, and in spite of the dominance of immature insects, it had a significant number of terrestrial insects during the heavy rainfall periods.

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 Measurements of Water Vapor Profiles with Compact DIAL in the Tokyo Metropolitan Area

2018 ◽  
Vol 176 ◽  
pp. 04015
Author(s):  
Makoto Abo ◽  
Tetsu Sakai ◽  
Phong Pham Le Hoai ◽  
Yasukuni Shibata ◽  
Chikao Nagasawa
Keyword(s):  
Water Vapor ◽  
Numerical Model ◽  
Heavy Rainfall ◽  
Lidar Data ◽  
Cumulus Convection ◽  
Frequency Of Occurrence ◽  
Early Prediction ◽  
Differential Absorption ◽  
Tokyo Metropolitan Area ◽  
Rainfall Prediction

In recent years, the frequency of occurrence of locally heavy rainfall that can cause extensive damages, has been increasing in Japan. For early prediction of heavy rainfall, it is useful to measure the water vapor vertical distribution upwind cumulus convection beforehand. For that purpose, we have been developing compact water vapor differential absorption lidar (DIAL). We show the results of the measurements with lidar in summer when the local heavy rainfall frequently occurs in Japan. We also show the preliminary result of the assimilation of the lidar data to the numerical model and impact on the heavy rainfall prediction.

scholarly journals Efficient Network Telemetry based on Traffic Awareness

2021 ◽  
Author(s):  
Cesar Gomez ◽  
Abdallah Shami ◽  
Xianbing Wang
Keyword(s):  
Machine Learning ◽  
Adverse Effect ◽  
Network Performance ◽  
Important Data ◽  
Network Bandwidth ◽  
Crucial Component ◽  
Traffic Awareness ◽  
The Status ◽  
Bandwidth Overhead ◽  
And Behavior

Network Telemetry (NT) is a crucial component in today’s networks, as it provides the network managers with important data about the status and behavior of the network elements. NT data are then utilized to get insights and rapidly take actions to improve the network performance or avoid its degradation. Intuitively, the more data are collected, the better for the network managers. However, the gathering and transportation of excessive NT data might produce an adverse effect, leading to a paradox: the data that are supposed to help actually damage the network performance. This is the motivation to introduce a novel NT framework that dynamically adjusts the rate in which the NT data should be transmitted. In this work, we present an NT scheme that is traffic-aware, meaning that the network elements collect and send NT data based on the type of traffic that they forward. The evaluation results of our Machine Learning-based mechanism show that it is possible to reduce by over 75% the network bandwidth overhead that a conventional NT scheme produces.

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.

Subsocial organization and behavior in broods of the obligate burrowing wolf spider Geolycosa turricola (Treat)

1989 ◽  
Vol 67 (4) ◽  
pp. 819-824 ◽  
Author(s):  
Gary L. Miller
Keyword(s):  
Aggressive Behavior ◽  
Chemical Communication ◽  
Kin Recognition ◽  
Wolf Spider ◽  
Life Strategy ◽  
Frequency Of Occurrence ◽  
Recognition Ability ◽  
Mutual Tolerance ◽  
And Behavior

Prolonged mutual tolerance is described for spiderlings in broods of the burrowing wolf spider Geolycosa turricola (Treat) (Lycosidae). The length of the tolerant phase is compared with that of the facultative burrower Lycosa georgicola Walckenaer. Specific behaviors are described from observations of pairs of spiderlings. The frequency of occurrence of these behaviors was studied in a series of bioassay experiments designed to test questions concerning the nature of the mechanism of communication among spiderlings, the length of the tolerance phase, and the ability to recognize siblings from nonsiblings. The results indicate that chemical communication is the principal form of communication between spiderlings. Aggressive behavior increased in pairs of spiderlings of increasing disparity of size. Geolycosa turricola spiderlings showed little kin recognition ability. The advantage of prolonged tolerance within the burrowing life strategy is discussed.

scholarly journals Regional Variability of Rain Clouds in the Amazon Basin as Seen by a Network of Weather Radars

2016 ◽  
Vol 55 (12) ◽  
pp. 2657-2675 ◽  
Author(s):  
I. Saraiva ◽  
M. A. F. Silva Dias ◽  
C. A. R. Morales ◽  
J. M. B. Saraiva
Keyword(s):  
Heavy Rainfall ◽  
Amazon Basin ◽  
Radar Reflectivity ◽  
Northern Coast ◽  
Regional Variability ◽  
Convective Systems ◽  
Diurnal Cycles ◽  
Weather Radars ◽  
Vertical Distributions ◽  
The Vertical Distribution

AbstractA new dataset based on 5 yr of operational meteorological weather radars from the Amazon Protection System has enabled new knowledge in relation to rainfall in the Amazon basin. The rainy features are analyzed for 10 different regions in terms of the annual and diurnal cycles of radar reflectivity, as well as the vertical distribution, in addition to lightning data. Similarities between the annual and diurnal cycles are found in the northwestern and western, southwestern and southern, and northeastern and northern Amazon. Nocturnal peaks are found in stratiform fraction in the southern, southwestern, western, northwestern, northern, central western, and coastal regions. The convective fractions in the western, northwestern, northern, and central eastern regions also show nocturnal peaks. The radar reflectivity vertical distributions analysis indicates that in the northern coast close to Belém, heavy rainfall with deep convective systems is observed throughout the year, while heavy rainfall in the central Amazon close to Manaus, Tefé, and Santarém occurs in the dry season. More oceanic-like clouds are also observed there and in other locations on the northern coast like Macapá, where the frequency of lightning is quite low. São Gabriel da Cachoeira, located in the northwest portion of the Amazon basin, has a regime with rainfall in all seasons with a slight decrease from August to October when the systems become more convective and have more lightning.

scholarly journals Feeding habits of Thoracocharax stellatus (Characiformes: Gasteropelecidae) in the upper rio Tocantins, Brazil

2007 ◽  
Vol 5 (1) ◽  
pp. 69-74 ◽  
Author(s):  
André L. Netto-Ferreira ◽  
Míriam P. Albrecht ◽  
Jorge L. Nessimian ◽  
Érica P. Caramaschi
Keyword(s):  
Fish Species ◽  
Riparian Vegetation ◽  
Feeding Habits ◽  
Stomach Contents ◽  
Foraging Activity ◽  
River Bank ◽  
Food Items ◽  
Hydroelectric Dam ◽  
Terrestrial Insects ◽  
Land Water

The silver hatchetfish Thoracocharax stellatus is one of the approximately 200 fish species recorded for the upper rio Tocantins, in the region where it was impounded by the Serra da Mesa hydroelectric dam. Analysis of the stomach contents of 88 specimens revealed a diet consisting almost entirely of insects (99.6%), most of which were terrestrial (87.6%). Ants, beetles, and mayflies were the main food items. Dawn and dusk seemed to be the periods of highest foraging activity for T. stellatus. As a specialist on terrestrial insects, this species has a close connection with the region near the river bank, where prey is provided from the associated riparian vegetation. Despite the impoundment and depletion of the land-water ecotone observed in later stages of reservoir formation, no significant changes in the diet of the few remnant specimens were recorded, which seems to indicate little feeding flexibility. Thus, feeding seemed to be an overriding factor for the displacement of this species after river impoundment.

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