scholarly journals FOOD RESOURCE SHARING AMONG BENTHIC AND NEKTONIC STREAM FISH SPECIES

2021 ◽  
Vol 47 ◽  
pp. e634
Author(s):  
Guilherme Raphael Camargo Arcanjo SILVA ◽  
Maurício CETRA
Keyword(s):  
Fish Species ◽  
Resource Sharing ◽  
Diet Composition ◽  
Food Resource ◽  
Niche Overlap ◽  
High Concentration ◽  
Insect Larvae ◽  
Significant Difference ◽  
Food Content ◽  
Water Ecosystems

Several tropical freshwater fish species are generally generalistic feeders, sometimes followed by a diet reduction during the period of decreased resource availability. This study aimed to analyze the dietary overlap between nektonic and benthic fish species. The stomachs of 82 obligatory nektonics and 52 benthic were removed. The diet composition for each individual was determined based on the analysis of the stomach content, and the contents were grouped into 11 categories. For the analysis of food items, the method of degree of food preference was used. To verify the niche overlap between benthic and nectonic, the Pianka index was applied. Benthic species consumed items across all 11 food categories and nektonic species consumed nine. The diet composition of species with nektonic and benthic habits showed a significant difference. Dietary overlapping suggests a supply of the same resources, as they are shared by both groups. The high concentration of water insect larvae in the food content of all sampled fish species, regardless of the position in the water column, shows the importance of insects in the water ecosystems. The composition of ecosystem diets is helpful towards understanding the community structure and can explain the coexistence between different fish’s groups where live in different micro-habitats and how tactics used to capture food which may minimize the effects of overlapping and competitive exclusion.

scholarly journals Implications of low food availability on resource partitioning among three species of Cichlidae (Pisces: Perciformes) in a Brazilian semi-arid reservoir

2015 ◽  
Vol 27 (1) ◽  
pp. 93-104 ◽  
Author(s):  
Bruno Renaly Souza Figueiredo ◽  
Gabrielle Joanne Medeiros Araujo ◽  
Márcio Joaquim da Silva ◽  
Elvio Sergio Figueredo Medeiros
Keyword(s):  
Food Availability ◽  
Fish Species ◽  
Resource Partitioning ◽  
Food Resource ◽  
Stomach Contents ◽  
Niche Overlap ◽  
Trophic Levels ◽  
Feeding Mode ◽  
Food Items ◽  
Semi Arid

AimResource partitioning has been recognized as a major driver affecting fish communities, with the potential to reduce interespecific competition. This is the result of differences in feeding apparatuses and feeding mode, location of the fish species in the water column and swimming ability, as well as type and size of prey and its availability. The present study surveys a highly limited aquatic system in semi-arid Brazil with regard to habitat and food availability, with very low diversity of fish, and poor in underwater habitat structures and prey, with the objective of understanding resource partitioning among fish species under such conditions.MethodsThree species of Cichlidae (Pisces: Perciformes) were sampled during the dry and wet seasons and had their stomach contents analyzed to evaluate food consumption. The resource partition among fish species was evaluated based on Pianka’s niche overlap index and tested for significance against null models.ResultsIt was observed a low overlap among the study species in food resource use, with individuals tending to specialize to select some food items. This is likely the result of low natural variation in abundance of specific food items associated with fish preferences (both morphological and behavioral).ConclusionsThese results support evidence that, in Brazilian semi-arid aquatic systems, coexistence of fish species seems to be enhanced by the partition of food items at specific trophic levels. Within this context, flow variability would have a key hole in fish coexistence by promoting a high diversity of aquatic habitat elements available for colonization of fish and their prey. Furthermore, food resources available to fish play an important role in this dynamics since prey foods are expected to vary in abundance as the habitat changes.

scholarly journals Feeding resource partitioning between two understorey insectivorous birds in a fragment of Neotropical cloud forest

2015 ◽  
Vol 75 (4 suppl 1) ◽  
pp. 176-183 ◽  
Author(s):  
M. A. Manhães ◽  
M. M. Dias ◽  
A. L. C. Lima
Keyword(s):  
Diet Composition ◽  
Prey Size ◽  
Cloud Forest ◽  
Niche Overlap ◽  
Southeastern Brazil ◽  
Insectivorous Birds ◽  
Insect Larvae ◽  
Montane Rain Forest ◽  
Use Of Resources ◽  
Niche Dimension

Abstract The food habits and niche overlap based on diet composition and prey size of two species of understorey insectivorous birds were investigated in an area of montane rain forest in the state of Minas Gerais, southeastern Brazil. A total of 43 birds were captured: 33 individuals of Conopophaga lineata (Conopophagidae) with 13 recaptures, and 10 individuals of Myiothlypis leucoblephara (Parulidae) with 12 recaptures, from which were obtained respectively 33 and 10 fecal samples. Fragments of 16 groups of arthropods, plus insect eggs, were identified in these samples. Conopophaga lineata predominantly consumed Formicidae (32%) and Isoptera (23.6%). However, the index of alimentary importance (AI) of Isoptera (3.53) was lower than other groups such as Formicidae (AI = 61.88), Coleoptera (AI = 16.17), insect larvae (AI = 6.95) and Araneae (AI = 6.6). Myiothlypis leucoblephara predominantly consumed Formicidae (28.2%) and Coleoptera (24.4%), although Coleoptera and Hymenoptera non-Formicidae had the highest values of AI (38.71 and 22.98 respectively). Differences in the proportions of the types of arthropods consumed by birds were not enough to reveal their separation into feeding niches (overlap = 0.618, p observed ≤ expected = 0.934), whereas differences in the use of resources was mainly due to the size of the prey (p<0.001), where C lineata, the species with the highest body mass (p<0.001) consumed larger prey. It is plausible that prey size is an axis of niche dimension that allows the coexistence of these species.

Dietary overlap and food resource partitioning among fish species of a tropical estuary in Northeastern Brazil

Gaia Scientia ◽  
2016 ◽  
Vol 10 (4) ◽  
pp. 86-95 ◽  
Author(s):  
Adna Ferreira da Silva Garcia ◽  
Ana Lúcia Vendel
Keyword(s):  
Resource Partitioning ◽  
Species Coexistence ◽  
Food Resource ◽  
River Estuary ◽  
Niche Overlap ◽  
Northeastern Brazil ◽  
Dietary Overlap ◽  
Feeding Niche ◽  
Tropical Environments ◽  
Food Resource Partitioning

The current work investigates dietary overlap and food partitioning among nine abundant carnivorous fishes caught in the shallow waters of the Paraíba do Norte river estuary, Paraíba State, Brazil. Fishes were sampled with a beach seine net between January and December 2008 and a total of 958 specimens had their stomach content analyzed. Crustacea was the dominant food resource for Lutjanus alexandrei, L. jocu and Bathygobius soporator, whereas Telostei were consumed mainly by Centropomus undecimalis and C. parallelus. In contrast, Polychaeta were preyed upon mainly by Diapterus rhombeus, Eucinostomus argenteus, Sciades herzbergii and S. parkeri. Although most species consumed similar food items, they did that in varying proportions and amounts. Overall, the niche overlap among species was low (< 0.60), but there were several cases where pair of species had their feeding niche highly overlapped (between 0.72 and 0.97). These findings corroborate the hypothesis that food resource partitioning determines species coexistence in estuarine tropical environments.

scholarly journals Drivers of Bornean Orangutan Distribution across a Multiple-Use Tropical Landscape

2021 ◽  
Vol 13 (3) ◽  
pp. 458
Author(s):  
Sol Milne ◽  
Julien G. A. Martin ◽  
Glen Reynolds ◽  
Charles S. Vairappan ◽  
Eleanor M. Slade ◽  
...  
Keyword(s):  
Forest Cover ◽  
Food Resource ◽  
Multiple Use ◽  
Natural Forests ◽  
Bornean Orangutan ◽  
Aerial Surveys ◽  
Significant Difference ◽  
The Difference ◽  
Fig Trees ◽  
Abundance And Distribution

Logging and conversion of tropical forests in Southeast Asia have resulted in the expansion of landscapes containing a mosaic of habitats that may vary in their ability to sustain local biodiversity. However, the complexity of these landscapes makes it difficult to assess abundance and distribution of some species using ground-based surveys alone. Here, we deployed a combination of ground-transects and aerial surveys to determine drivers of the critically endangered Bornean Orangutan (Pongo pygmaeus morio) distribution across a large multiple-use landscape in Sabah, Malaysian Borneo. Ground-transects and aerial surveys using drones were conducted for orangutan nests and hemi-epiphytic strangler fig trees (Ficus spp.) (an important food resource) in 48 survey areas across 76 km2, within a study landscape of 261 km2. Orangutan nest count data were fitted to models accounting for variation in land use, above-ground carbon density (ACD, a surrogate for forest quality), strangler fig density, and elevation (between 117 and 675 m). Orangutan nest counts were significantly higher in all land uses possessing natural forest cover, regardless of degradation status, than in monoculture plantations. Within these natural forests, nest counts increased with higher ACD and strangler fig density, but not with elevation. In logged forest (ACD 14–150 Mg ha−1), strangler fig density had a significant, positive relationship with orangutan nest counts, but this relationship disappeared in a forest with higher carbon content (ACD 150–209 Mg ha−1). Based on an area-to-area comparison, orangutan nest counts from ground transects were higher than from counts derived from aerial surveys, but this did not constitute a statistically significant difference. Although the difference in nest counts was not significantly different, this analysis indicates that both methods under-sample the total number of nests present within a given area. Aerial surveys are, therefore, a useful method for assessing the orangutan habitat use over large areas. However, the under-estimation of nest counts by both methods suggests that a small number of ground surveys should be retained in future surveys using this technique, particularly in areas with dense understory vegetation. This study shows that even highly degraded forests may be a suitable orangutan habitat as long as strangler fig trees remain intact after areas of forest are logged. Enrichment planting of strangler figs may, therefore, be a valuable tool for orangutan conservation in these landscapes.

Comparative Study on Vit. E & Mefenamic acid vs Mefenamic acid alone on mean reduction in pain in Primary Dysmenorrhea

2021 ◽  
Vol 15 (12) ◽  
pp. 3195-3197
Author(s):  
Fariha Sadiqa ◽  
Mufakhara Fatimah ◽  
Abdul Mudabbir Rehan ◽  
Sidra Mushtaq ◽  
Asia Firdous ◽  
...  
Keyword(s):  
Vitamin E ◽  
Mefenamic Acid ◽  
Controlled Trial ◽  
Acid Group ◽  
P Value ◽  
Primary Dysmenorrhea ◽  
High Concentration ◽  
Randomized Controlled ◽  
Significant Difference ◽  
Menstrual Fluid

Background: Pelvic pain around the time of mensturation without any identifiable pathologic lesion present from menarche is called primary dysmenorrhea. The pain is believed to be related to prostaglandin (PG). Women with dysmenorrhoea have a relatively high concentration of PGF 2 alpha in menstrual fluid and suppression of PG synthesis has become the main treatment. Aim: To compare mean reduction in pain in patients presenting with primary dysmenorrhea given vitamin E & Mefenamic acid versus Mefenamic acid alone. Results: It was a randomized controlled trial which was conducted in Department of Obstetrics & Gynecology, THQ Raiwind Hospital, Lahore for 6 months duration w.e.f 01/02/2017 to 31/07/2017. In this study, 18(36%) in Vitamin-E group and 21(42%) in Mefenamic acid group were between 15-20 years while 32(64%) in Vitamin-E group and 29(58%) in Mefenamic acid group were between 21-25 years, mean±sd was calculated as 20.86±2.92 and 20.66±2.86 years respectively, mean dysmenorrheal pain at baseline was recorded as 50.06±10.27 in Vitamin-E group and 50.14±10.28 in Mefenamic acid group, p value < 0.754, showing that both groups are insignificant, mean dysmenorrheal pain after treatment was recorded as 20.50±10.04 in Vitamin-E group and 30.22±10.28 in Mefenamic acid group, p value was < 0.002 showing significant difference between the two group, comparison of mean reduction in dysmenorrheal pain after treatment was recorded as 20.56±0.91 in Vitamin-E group and 10.92±0.75 in Mefenamic acid group, p value was < 0.000, showing significant difference. Conclusion: We concluded that there is a significant mean reduction in dysmenorrhic pain in patients given Mefenamic Acid + Vitamen E as compared to patients given Mefenamic Acid alone. Keywords: Dysmenorrhic pain, Mefenamic Acid + Vitamen E, mean reduction in dysmenorrhic pain

Proximate composition of male and female African catfish (Clarias gariepinus) and tilapia (Tilapia zilli) in Jega river, Kebbi state, Nigeria

2020 ◽  
Vol 01 (02) ◽  
pp. 28-35
Author(s):  
W. M. Namaga ◽  
B. Yahaya ◽  
M. A. Salam
Keyword(s):  
Protein Content ◽  
Fish Species ◽  
Lipid Content ◽  
Proximate Composition ◽  
Clarias Gariepinus ◽  
Fibre Content ◽  
African Catfish ◽  
Male And Female ◽  
Juvenile Female ◽  
Significant Difference

Fish is highly nutritious, tasty, and easily digestible. It is much sought after by a broad cross-section of the world’s population, particularly in developing countries as it provides the cheapest protein source. Nigeria is blessed with numerous inland freshwater rivers and lakes scattered all over the country. This freshwater habitat consists of many species of fish that have successfully dominated all niches over time and have for many reasons remained unstudied. The situation concealed a lot of scientific information particularly on food security and safety to the inmates and the country at large. Jega River which transcended many States in the North-Western part of Nigeria to open into the river Niger is one of such rivers largely uncared for, study-wise. African catfish (Clarias gariepinus) and Tilapia (Tilapia zillii) have been wisely selected for the present proximate composition studies. The juveniles of these fishes were purchased from local fishermen in Mariner Waje landing site of the river which flows by Jega town, a local government area in Kebbi State, Nigeria. For the study, the methodology approved by the Association of Official Analytical Chemists (AOAC) was used to determine the proximate composition of the fishes. The highest percentage crude protein content of 49.18 ± 0.30% was observed in juvenile female C. gariepinus; while the lowest protein content of 39.22± 0.50% was observed in juvenile male T. zilli. The highest percentage lipid content of 11.75± 1.50% was observed in juvenile female tilapia; while the lowest percentage lipid content of 6.25± 0.29% was observed in male African catfish. The highest percentage fibre content of 4.00 ± 0.29% was observed in male and female C. gariepinus, while the lowest percentage fibre content of 0.75± 0.29% was observed in male tilapia. There were variations (p< 0.05) when the protein and lipid contents of both the species were compared with each other. There was also a significant difference (p< 0.05) when the carbohydrate contents were compared between the fish species, but there was no significant difference (p > 0.05) when the fibre content was compared within the species. The analyses showed that both the male and female fish species studied had high protein contents.

scholarly journals Trophic interactions among sympatric zooplanktivorous fish species in volume change conditions in a large, shallow, tropical lake

2011 ◽  
Vol 9 (1) ◽  
pp. 169-176 ◽  
Author(s):  
Rodrigo Moncayo-Estrada ◽  
Owen T Lind ◽  
Carlos Escalera-Gallardo
Keyword(s):  
Niche Breadth ◽  
Temporal Distribution ◽  
Niche Overlap ◽  
Species Interaction ◽  
Trophic Relationships ◽  
Water Volume ◽  
Species Flock ◽  
Small Range ◽  
Mean Values ◽  
Significant Difference

Significant reductions in the water volume of shallow lakes impose a restriction on species segregation promoting more interactions in the trophic relationships. The diets of three closely related zooplanktivorous silversides belonging to the Atherinopsidae species flock of lake Chapala , Mexico, were analyzed at two sites (Chirostoma jordani, C. labarcae, and C. consocium). Diets were described in critical shallow (August 2000) and volume recovery conditions (August 2005). Diets included mainly cladocerans (Bosmina, Ceriodaphnia, and Daphnia) and copepods (Cyclops). A significant difference in diets was detected when comparing years (MRPP analysis, A = 0.22, p < 0.0001) and sites at different years (MRPP analysis, A = 0.17, p = 0.004). According to niche breadth mean values, species were classified as specialized and intermediate feeders. In shallow conditions, the small range of niche breadth (1.72 to 3.64) and high diet overlap values (D = 0.64, L = 8.62) indicated a high potential for interspecific exploitative interaction. When the lake volume recovered, an increase in the niche breadth range (1.04 to 4.96) and low niche overlap values (D = 0.53, L = 2.32) indicated a reduction of the species interaction. The Mann-Whitney U-test supported this pattern by showing a significant difference between years for niche overlap (p = 0.006). The increased interaction during the low volume suggests alternative segregation in life-history variations and other niche dimensions such as spatial or temporal distribution.

scholarly journals Impact of Biochar on Douglas-Fir Tussock Moth (Orgyia pseudotsugata Lepidoptera: Erebidae) Larvae Reared on Synthetic Die

Insects ◽  
2021 ◽  
Vol 12 (12) ◽  
pp. 1065
Author(s):  
Stacey Rice-Marshall ◽  
Stephen P. Cook ◽  
John Randall
Keyword(s):  
Weight Gain ◽  
Larval Mortality ◽  
Douglas Fir ◽  
High Concentration ◽  
Larval Weight ◽  
Synthetic Diet ◽  
Tussock Moth ◽  
Orgyia Pseudotsugata ◽  
Compensatory Feeding ◽  
Significant Difference

The use of biochar as a soil amendment in forest ecosystems can be beneficial in the restoration of degraded soils. Forest insects such as the Douglas-fir tussock moth, Orgyia pseudotsugata (McDonnough) (Lepidoptera: Erebidae), may be exposed to biochar when the material is applied. Two experiments were conducted using biochar either (1) applied to the surface of the diet at three rates (0, 5, and 10 mg) or (2) incorporated into synthetic diet at four rates (0, 10, 20, and 40% volume/volume). The objective of both experiments was to determine if biochar on the surface or incorporated into a synthetic diet affected development and survival of O. pseudotsugata larvae. In both experiments, there was a significant decrease in estimated time to larval mortality in all biochar treatments compared to untreated controls. In the surface-applied biochar experiment, there was a significant difference in larval weight gain at day 12 between the control and 10 mg biochar treatments. In the experiment with biochar incorporated into the diet, mean larval weight at day 12 was highest in the low (10%) biochar treatment compared to all other treatments, although weight gain was only significantly different between the low- and high-concentration (40%) biochar treatments. Our results suggest that larvae, feeding on a low amount of biochar in the synthetic diet, may respond by engaging in compensatory feeding behavior. Fewer surviving larvae in the biochar treatment groups may contribute to the lack of significance found in the comparison of weight gain at day 24 in each experiment.

scholarly journals FEEDING HABITS AND HELMINTH PARASITES OF SARDINE (S. PILCHARDUS) AND ANCHOVY (E. ENCRASICOLUS) IN THE ADRIATIC SEA

2015 ◽  
Vol 17 (1) ◽  
pp. 216 ◽  
Author(s):  
B. ZORICA ◽  
V. ČIKES KEČ ◽  
O. VIDJAK ◽  
I. MLADINEO ◽  
D. EZGETA BALIČ
Keyword(s):  
Diet Composition ◽  
Feeding Habits ◽  
Stomach Contents ◽  
Stomach Content Analysis ◽  
Helminth Parasites ◽  
Significant Difference ◽  
Prey Composition ◽  
One Year ◽  
Paratenic Hosts ◽  
Hysterothylacium Aduncum

We examined the stomach contents of two of the most economically and ecologically important small pelagic fish species, the sardine, Sardina pilchardus and the anchovy, Engraulis encrasicolus, obtained monthly from commercial purse-seine catches operating on Croatian fishing grounds during a one-year period (January–December, 2011). Both species generally showed a similar diet, with copepod and decapod larvae as dominant prey groups. The composition of anchovy and sardine stomach contents was not size- or sex-related, but throughout the year, a significant difference in diet composition was observed for each species as well as between species. Two gastrointerstinal helminths; the digenean Parahemiurus merus and nematode Hysterothylacium aduncum, were recorded during the stomach content analysis. Differences in population dynamics between the two parasites are congruent with differences in the prey composition of sardine and anchovy, reflecting fine-tuned interactions in the trophic web between parasites and intermediate or paratenic hosts included in the sardine and anchovy diet.

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