scholarly journals Spatial and seasonal changes in the diet of Oligosarcus hepsetus (Characiformes, Characidae) in a Brazilian Reservoir

2005 ◽  
Vol 65 (1) ◽  
pp. 1-8 ◽  
Author(s):  
F. G Araújo ◽  
C. C Andrade ◽  
R. N Santos ◽  
A. F. G. N Santos ◽  
L. N Santos
Keyword(s):  
Seasonal Changes ◽  
Prey Capture ◽  
Gut Contents ◽  
Relative Importance ◽  
Food Items ◽  
Dietary Shifts ◽  
Index Of Relative Importance ◽  
Almost All ◽  
Previous Autumn ◽  
Very High

We assessed spatial and seasonal changes in the diet of Oligosarcus hepsetus in order to describe the strategy developed by this species that allows their very high abundance in Lajes reservoir, Rio de Janeiro, Brazil. Fish samplings were carried out using gill nets, deployed during ca. 12 and 24 hours, between April 2001 and May 2002. A total of 289 individuals were examined, of which 97 showed gut contents. We used the index of relative importance (IRI) to compare probable dietary shifts, and the frequency of occurrence (% OC) to analyze possible ontogenetic influences on feeding. O. hepsetus showed carnivorous habits, feeding preferably on fish and insects, the latter of which occurred in 71.0% of the guts presenting contents. O. hepsetus consumed different items along the three reservoir zones: insects (61.0% IRI) and Cichla monoculus (38.9% IRI) in the lower zone; Lepidoptera (57.0% IRI) in the middle zone; and C. monoculus (77.0% IRI) in the upper zone. Food items changed seasonally with C. monoculus predominating in autumn 2001, and Hymenoptera and Lepidoptera in the winter. In spring almost all food was Lepidoptera (99.8% IRI), while in the summer Hemiptera dominated in the diet. In autumn 2002 Hemiptera (97.0% IRI) was dominant, in significant contrast with the previous autumn. Individuals smaller than 190 mm SL fed heavily on insects, while fishes predominated in the diet of individuals larger than 190 mm SL. Shifts in prey-capture ability among length classes suggest decreasing intraspecific competition. A higher food plasticity seems to be the strategy employed by this opportunist species, which used food resources available in the reservoir.

scholarly journals Aspectos da alimentação natural de Larimus breviceps Cuvier, 1830, proveniente do litoral norte da Paraíba, Brasil

2020 ◽  
Vol 1 (52) ◽  
pp. 185
Author(s):  
Andreza Da Silva Nascimento ◽  
Jonas De Assis Almeida Ramos
Keyword(s):  
Feeding Habits ◽  
Food Composition ◽  
Marine Debris ◽  
Northern Coast ◽  
Relative Importance ◽  
Synthetic Material ◽  
Fish Feeding ◽  
Food Items ◽  
Index Of Relative Importance ◽  
Social Importance

<p>The knowledge of natural fish feeding is important to understand the species feeding habits and how they interact with the environment. In addition to that, this kind of research can provide relevant data to improve the capture of these animals, considering their economy and social importance. This study aimed to analyze the food composition of Larimus breviceps specimens from the northern coast of Cabedelo city, evaluating the importance of each food item for their diet. The specimens came from the local artisanal fisheries. In laboratory, the individuals were identified, measured and dissected to remove the stomachs content and then examined. Three different analyzes were performed, percentage by frequency of occurrence, by number and by weight, then the index of relative importance (IRI%) was computed. In total, 30 stomachs were analyzed, 15 distinct food items were identified, the most representative prey were fish fragments, Copepoda, Gammaridae, Decapoda (shrimp), algal fragments and synthetic material. Given the results, the diet of this species becomes more diversified as young individuals reach the adults size, and ingest marine debris which indicates an anthropogenic impact.</p>

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.

Diets of commercially exploited fish from Bass Strait and adjacent Victorian Waters, south-eastern Australia

1984 ◽  
Vol 35 (5) ◽  
pp. 549 ◽  
Author(s):  
N Coleman ◽  
M Mobley
Keyword(s):  
Stomach Contents ◽  
Relative Importance ◽  
Food Items ◽  
South Eastern ◽  
Major Food ◽  
Eastern Australia ◽  
Commercial Species ◽  
Index Of Relative Importance ◽  
South Eastern Australia

Stomach contents were analysed to investigate the diets of 52 commercial species of fish. Fish were collected from Bass Strait and adjacent Victorian waters, south-eastern Australia; samples effectively covered the whole of the Victorian coast. Particular emphasis was placed on estimating the importance of arrow squid, Nototodarus gouldri in the diets of the species investigated. For most of the species investigated, the major food items (expressed as the proportion of stomach contents by number, weight and volume or through the calculation of the Index of Relative Importance) were fish or crustaceans. Cephalopods were found in the diets of 21 species but provided a major proportion of the stomach contents in only six species. Arrow squid did not appear to be a major item in the diets of any of the species investigated. For those species that eat large amounts of cephalopods, it appears to be octopus, rather than squid, that is of most significance in the diet.

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.

Observations on the diet and feeding habits of the epaulette shark, Hemiscyllium ocellatum (Bonnaterre), on Heron Island Reef, Great Barrier Reef, Australia

1998 ◽  
Vol 49 (7) ◽  
pp. 753 ◽  
Author(s):  
M. R. Heupel ◽  
M. B. Bennett
Keyword(s):  
Content Analysis ◽  
Reef Flat ◽  
Prey Capture ◽  
Feeding Habits ◽  
Stomach Content Analysis ◽  
Relative Importance ◽  
Barrier Reef ◽  
Epaulette Shark ◽  
Index Of Relative Importance ◽  
Prey Items

The diet and feeding habits of the epaulette shark, Hemiscyllium ocellatum, were investigated through stomach content analysis. Five groups of prey items were found. The index of relative importance showed worms and crabs to be of greatest value at 51.3% and 40.1% respectively. The three minor prey groups were shrimps (7.7%), small fishes (0.7%) and amphipods (0.3%). Epaulette sharks tend to be crepuscular, although feeding bouts may occur at any time. They appear to be opportunistic predators, using olfaction and electroreception in prey capture. This species appears to be an important benthic predator in the reef flat environment on Heron Island Reef.

scholarly journals Feeding habit of Brown trout (Salmo trutta fario) in upper parts of river Swat, Pakistan

2022 ◽  
Vol 82 ◽  
Author(s):  
W. Khan ◽  
S. M. H. M. Naqvi ◽  
H. Ullah Khan ◽  
M. Rafiq ◽  
B. Ahmad ◽  
...  
Keyword(s):  
Body Weight ◽  
Brown Trout ◽  
Salmo Trutta ◽  
Gut Contents ◽  
Relative Importance ◽  
Feeding Intensity ◽  
Total Length ◽  
Index Of Relative Importance ◽  
The Relationship ◽  
Salmo Trutta Fario

Abstract Salmo trutta fario is the most important fish species of family Salmonidae inhibited in cool waters all over the world including the nortern parts of Pakistan. This study was aimed to find out the prey selection and feeding habits of the species. One hundred and eighty five Salmo trutta fario were captured from March 2016 to April 2017. Feeding intensity as represented by a fullness index (FI), changing with various length groups and season. Out of 185 Brown trout 24 fish stomaches were found empty. The most important and common food items of brown trout were Brachycentridae, Blepharocera, Hydropsychidae, ephemerella spp. Kruskal Wallis H-test were applied on feeding intensity groups consisting of three month group. The test statistic for K.W-H-test were (H=8.13 with df =3) had a p-value of 0.043 < (alpha=0.05 indicates favor of the alternative hypothesis of at least one difference among the feeding intensity groups. The linear relationship of N with index of relative importance and %IRI denoted by least square regression line (N = 35.2 + 22.1%IRI), shows that for 22 prey there is 1% change in IRI. The relationship between total length (mm) and fish body weight (gm) is expressed by Pearson correlation coefficient (r = 0.976), showed that total length (mm) and fish body weight (gm.) is highly correlated. Descriptive statistics are used for the stomach fullness, which shows that feeding intensity was recorded higher from March to May. A total of 2289 preys was recorded including the most common were; Trichoptera, Hydropsychidae, Brachycentridae, diptera, blepharocera, ephemerala, chironomida, honey bees, grass hopper, locust, trout egg, trochanter, plant tissue, stones were retrieved from the gut contents of brown trout. According to index of relative importance IRI% four preys represents major components of the diet. The highest IRI% was recorded in Brachycentridae (39.38%), followed by blepharocera (13.23%), Hydropsychidae (10.76%) and ephemerella spp (8.28%). The relationship between IRI and FO is (r =0.556) is moderately correlated with coefficient of determination (r2=0.31). This study will help in the development of an artificial diet for the species for better growth performance in captivity.

Diet of Hydromedusa tectifera (Testudines-Chelidae) in a mountain stream of Córdoba province, Argentina

2009 ◽  
Vol 30 (4) ◽  
pp. 545-554 ◽  
Author(s):  
Julián Lescano ◽  
Marcelo Bonino ◽  
Gerardo Leynaud ◽  
José Haro
Keyword(s):  
Diversity Index ◽  
Stomach Contents ◽  
Detrended Correspondence Analysis ◽  
Mountain Streams ◽  
Mountain Stream ◽  
Relative Importance ◽  
Size Classes ◽  
Food Items ◽  
Index Of Relative Importance ◽  
Morisita Index

AbstractThe diet of Hydromedusa tectifera occurring in two mountain streams in the province of Córdoba is described through a comparative analysis of 154 individuals. Turtles were manually captured between August 2005 and August 2006 from streams at the localities of Tanti and Flor Serrana. Before being released, turtles were stomach-flushed, and sex and carapace length were recorded. The stomach contents were observed under stereomicroscope; prey items were identified and classified according to size and volume. The importance of the different items was quantified using the Index of Relative Importance (IRI). Similarity in the diet between sexes and among size classes and seasons of an annual cycle was evaluated using the simplified Morisita index. Trophic breadth was estimated with the Shannon diversity index. Detrended Correspondence Analysis (DCA) was used to evaluate differences in the diet between categories (sex, size classes). Forty-seven food items belonging to the following taxa were identified: leeches, annelids, gastropods, arachnids, insects, and fishes. According to the IRI value, the most important items in the diet of H. tectifera were larvae of Trichoptera (IRI = 33.5), fishes (IRI = 30), and naiads of Odonata (IRI = 25.2). The relative importance of the items varied with size of turtles but not with sex. Size of prey consumed increased with increasing turtle size. A greater trophic breadth was observed in smaller individuals.

scholarly journals Niche enlargement as a consequence of co-existence: a case study

2012 ◽  
Vol 72 (2) ◽  
pp. 267-274 ◽  
Author(s):  
R. Mazzoni ◽  
PS. Marques ◽  
CF. Rezende ◽  
R. Iglesias-Rios
Keyword(s):  
Seasonal Changes ◽  
Niche Breadth ◽  
Stomach Contents ◽  
Niche Overlap ◽  
Relative Importance ◽  
Main Prey ◽  
Food Items ◽  
Spatio Temporal ◽  
Prey Items

Spatio-temporal changes in the diet, niche breadth and niche overlap of two species of Characidium from three different sites along a Neotropical coastal stream were studied during a dry and rainy season. Seasonal changes were restricted to the occurrence of plant items in the stomach contents. The relative importance of food items in the diet of both species varied across sites, but Diptera, Ephemeroptera, Simuliidae, Trichoptera and Coleoptera larvae were always the main prey items. Contrary to the expected pattern, values of the niche breadth were higher at the site where Characidium species co-existed and niche overlapped at this site indicated 52% (p = 0.52) of feeding overlap.

scholarly journals Chironomidae feeding habits in different habitats from a Neotropical floodplain: exploring patterns in aquatic food webs

2016 ◽  
Vol 76 (1) ◽  
pp. 117-125 ◽  
Author(s):  
C. M. M. Butakka ◽  
F. H. Ragonha ◽  
S. Train ◽  
G. D. Pinha ◽  
A. M. Takeda
Keyword(s):  
Food Webs ◽  
Feeding Habits ◽  
Fungal Spores ◽  
Gut Contents ◽  
Larval Feeding ◽  
Gut Content ◽  
Aquatic Communities ◽  
Food Items ◽  
Aquatic Food ◽  
Almost All

Abstract Ecological studies on food webs have considerably increased in recent decades, especially in aquatic communities. Because Chironomidae family are highly specious, occurring in almost all aquatic habitats is considered organisms-key to initiate studies on ecological relationships and trophic webs. We tested the hypothesis that the diversity of the morphospecies diet reflects differences on both the food items available among habitats and the preferences of larval feeding. We analyzed the gut content of the seven most abundant Chironomidae morphospecies of the different habitats from the Upper Paraná River. We categorized the food items found into algae, fungal spores, fragments of plants, algae and animal fragments and sponge spicules. We observed the algae predominance in the gut content of morphospecies from lakes. Considering the different regions from each lake, we registered the highest food abundance in the littoral regions in relation to the central regions. From the variety of feeding habits (number of item kinds), we classified Chironomus strenzkei, Tanytarsus sp.1, Procladius sp.1 as generalist morphospecies. We found a nested pattern between food items and Chironomidae morphospecies, where some items were common to all taxa (e.g., Bacillariophyceae algae, especially), while others were found in specific morphospecies (e.g., animals fragments found in Procladius sp.1). The algae represented the most percentage of gut contents of Chironomidae larvae. This was especially true for the individuals from littoral regions, which is probably due to the major densities of algae associated to macrophytes, which are abundant in these regions. Therefore, the feeding behavior of these morphospecies was generalist and not selective, depending only of the available resources.

Feeding habits of the apron ray,Discopyge tschudii(Elasmobranchii: Narcinidae), from off Uruguay and northern Argentina

2012 ◽  
Vol 93 (2) ◽  
pp. 291-297 ◽  
Author(s):  
M. Cecilia Spath ◽  
Santiago A. Barbini ◽  
Daniel E. Figueroa
Keyword(s):  
Body Size ◽  
Seasonal Changes ◽  
Feeding Habits ◽  
Cold Season ◽  
Relative Importance ◽  
Multiple Hypothesis ◽  
Index Of Relative Importance ◽  
Discopyge Tschudii ◽  
Modelling Approach

The feeding habits of the apron ray,Discopyge tschudii, were investigated, off Uruguay and northern Argentina, and we tested the hypothesis that the diet changes with increasing body size, between sexes and seasons using a multiple-hypothesis modelling approach.Discopyge tschudiipreys mainly on polychaetes (88.77% index of relative importance (IRI)) followed by siphons of the clamAmiantis purpurata(8.13% IRI) and amphipods (3.08% IRI). Ontogenetic, sexual and seasonal changes were found. Larger individuals ofD. tschudiiconsumed buried polychaetes more often. The consumption of errant polychaetes was higher in males and in the cold season. Also, amphipods were preyed on more heavily by females and the number of siphons ofA. purpurataconsumed was higher in the cold season.

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