Feeding ecology of the southern thorny skate,Amblyraja doellojuradoion the Argentine Continental Shelf

2013 ◽  
Vol 93 (8) ◽  
pp. 2207-2216 ◽  
Author(s):  
G.E. Delpiani ◽  
M.C. Spath ◽  
D.E. Figueroa
Keyword(s):  
Continental Shelf ◽  
Generalized Linear Models ◽  
Feeding Ecology ◽  
Sexual Maturity ◽  
Linear Models ◽  
Feeding Habits ◽  
Benthic Fauna ◽  
Relative Importance ◽  
The North ◽  
Index Of Relative Importance

The feeding ecology of the southern thorny skate,Amblyraja doellojuradoi, on the Argentine Continental Shelf was evaluated using generalized linear models.Amblyraja doellojuradoipreyed mainly on crabs (85.41% index of relative importance (IRI)) and to a lesser extent on polychaetes (4.98% IRI), teleosts (3.28% IRI), isopods (2.03% IRI), other crustaceans (1.52% IRI) and other invertebrates (2.78% IRI). As individuals increased in size, the consumption of crabs also increased and the consumption of polychaetes and other invertebrates decreased. The study area was divided into a northern (36°–43°S) and a southern (43°–50°S) region. Regarding the latitude of capture, it was observed thatA. doellojuradoimainly fed on crabs in the north and on fish, isopods and other crustaceans in the south. Females ofA. doellojuradoihad a stronger preference for fish and isopods than males. As to sexual maturity, immatures fed more on polychaetes and other crustaceans than did mature. The ontogenetic change in feeding habits could be attributed to body size and an increasing ability to capture larger prey, rather than to food availability. However, this point cannot be confirmed because little is known about the benthic fauna of this area.

Temporal and ontogenic variations of diet of the goldblotch grouper Epinephelus costae (Serranidae) in the eastern coast of Algeria

2016 ◽  
Vol 97 (2) ◽  
pp. 259-267
Author(s):  
Raouf Zaidi ◽  
Farid Derbal ◽  
M. Hichem Kara
Keyword(s):  
Sexual Maturity ◽  
Feeding Habits ◽  
Eastern Coast ◽  
Female Size ◽  
Relative Importance ◽  
Diverse Range ◽  
Male And Female ◽  
Qualitative And Quantitative ◽  
Index Of Relative Importance ◽  
Digestive Contents

The diet of the goldblotch grouper Epinephelus costae of the eastern coast of Algeria was studied from March 2011 to February 2012. A total of 275 individuals, whose total length varied between 21.1 and 79.79 cm and weight between 103.13 and 5390.00 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 sexual maturity (immature and mature), sex (male and female), size (small, medium and large) and seasons. The average annual digestive vacuity is 17.82%. It does not vary according to sex, size or maturity, but is different between summer and winter. Qualitative analysis of digestive contents reveals a fairly diverse range of predation with 319 prey counted for a total weight of 934.85 g, which corresponds to an average number (Nm) and weight (Wm) of 1.4 and 4.14 g respectively. This species feeds on benthopelagic prey composed mainly of bony fish (%IRI = 76.16), pancrustacea (%IRI = 16.14) and molluscs (%IRI = 6.24). All other prey were accessory (plants) or accidental (annelids). Significant differences in feeding habits occur according to seasons and fish size.

Intrapopulation variation in the diet of franciscana dolphin (Pontoporia blainvillei) off southern Brazil

2021 ◽  
pp. 1-17
Author(s):  
Manuela Bassoi ◽  
Eduardo R. Secchi ◽  
Daniel Danilewicz ◽  
Ignacio B. Moreno ◽  
Roberta A. Santos ◽  
...  
Keyword(s):  
Sexual Maturity ◽  
Linear Models ◽  
Prey Species ◽  
Prey Availability ◽  
Prey Selection ◽  
Feeding Habits ◽  
Stomach Contents ◽  
Brazilian Coast ◽  
Pontoporia Blainvillei ◽  
Franciscana Dolphin

Abstract The franciscana dolphin (Pontoporia blainvillei) is a coastal dolphin endemic to the western South Atlantic Ocean. The dolphin is listed as vulnerable in the IUCN Red List, with incidental catches in gillnet fisheries the greatest conservation concern for this species. Insights into the feeding habits of this dolphin are essential to understand its distribution, movements and use of habitat, which are fundamental for effective management of the species. The feeding habits of franciscana dolphins were investigated from analyses of stomach contents of animals incidentally caught by two fishing operations from southern and northern regions of the southern Brazilian coast. In this study we investigate the existence of intrapopulation (sexual maturity and sex-related) variation in the diet of the franciscana dolphin, evaluating the spatial (northern and southern geographic areas) and seasonal influences. The analyses were based on Linear and Generalized Linear Models (LM and GLM). The majority of identified prey species were bottom-dwelling teleosts and the squid Doryteuthis sanpaulensis. The most important prey differed spatially and seasonally between northern and southern regions of the study area, and our results revealed significant differences between sexes and sexual maturity stages, mainly related to prey species sizes. This variation might indicate differences in prey selection, availability or habitat use patterns among these groups. In any case, these dietary differences are likely to minimize intraspecific competition for food resources, and/or indicate spatio-temporal variation in prey availability.

scholarly journals Chilling to the bone: Lower temperatures increase vertebrate predation by Tonatia bidens (Chiroptera: Phyllostomidae)

2020 ◽  
Vol 37 ◽  
pp. 1-5
Author(s):  
Fernando Carvalho ◽  
Daniela A.S. Bôlla ◽  
Viviane Mottin ◽  
Suelen Zonta Kiem ◽  
Jairo J. Zocche ◽  
...  
Keyword(s):  
Environmental Factors ◽  
Generalized Linear Models ◽  
Negative Binomial Distribution ◽  
Diet Composition ◽  
Linear Models ◽  
Negative Binomial ◽  
Meteorological Station ◽  
Foraging Patterns ◽  
Influence Of Temperature ◽  
The North

The greater round-eared bat, Tonatia bidens (Spix, 1823), is a medium-sized phyllostomid bat distributed in the north of Argentina, Paraguay and Brazil. The diet and foraging patterns of this species are poorly known. We analyzed the composition of the diet of a population of T. bidens and how the temperature influences the consumption of vertebrates and invertebrates. To describe diet composition, we conducted weekly collections of food scrap from two monospecific night-perches. Data of temperature for the study period were taken from the meteorological station installed 300 m from the collection perches. The influence of temperature was evaluated using generalized linear models (GLMs) with negative binomial distribution. Tonatia bidens consumed 28 taxons (204 records), being at least 17 Artropods and 11 Passeriformes birds. Temperature explained a greater proportion of vertebrate abundance (R2 = 0.23) than invertebrate (R2 = 0.16) or to both pooled (R2 = 0.11). The relation with temperature was positive with invertebrates and negative with the vertebrates. The diet of the population of T. bidens comprised mainly invertebrates, which were the most frequent and diverse taxa. Data suggests that T. bidens has a diverse diet, with proportion of the item’s consumption varying temporally. Environmental factors, such as the temperature presented on this work, seems to be good proxies for the dietary traits of this species.

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 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 Food resource utilization of the skates Rioraja agassizii (Müller & Henle, 1841) and Psammobatis extenta (Garman, 1913) on the continental shelf off Ubatuba, South-eastern Brazil

2001 ◽  
Vol 61 (2) ◽  
pp. 217-238 ◽  
Author(s):  
E. Y. MUTO ◽  
L. S. H. SOARES ◽  
R. GOITEIN
Keyword(s):  
Feeding Habits ◽  
Food Resource ◽  
Stomach Content Analysis ◽  
Brazilian Coast ◽  
Relative Importance ◽  
Important Food ◽  
South Eastern ◽  
Eastern Brazil ◽  
Index Of Relative Importance ◽  
Food Resource Utilization

The feeding habits of Rioraja agassizii (syn. Raja agassizii) and Psammobatis extenta (syn. Psammobatis glansdissimilis) of the South-eastern Brazilian coast were studied by means of stomach content analysis. The samples were obtained on eight seasonal oceanographic cruises, carried out between October 1985 and July 1987. The importance of each food item was evaluated on the basis of the Index of Relative Importance and the feeding similarity by Percentage of Similarity. The results indicated that both species are benthic feeders, preying mainly on Crustacea, especially Amphipoda, Caridea and Brachyura. Teleostei were also important for R. agassizii. Seasonal variation of the diet seems to be associated with the availability of the prey, whose distribution and abundance are related to the dynamics of the water masses of the region. Juveniles and adults of P. extenta exploited the same resources while juveniles and adults of R. agassizii presented low diet similarity during most of the year. Caridea were an important food for all length classes of R. agassizii, while Amphipoda were for smaller specimens, and Teleostei for larger ones. The feeding overlap between the two species was higher during autumn 1986, winter 1986 and winter 1987.

Feeding ecology of the piked spurdog Squalus megalops (Chondrichthyes: Squalidae) in the Gulf of Gabès (central Mediterranean Sea)

2018 ◽  
Vol 69 (1) ◽  
pp. 48
Author(s):  
Sondes Marouani ◽  
Hasna Kadri ◽  
Sami Karaa ◽  
Mohamed Nejmeddine Bradai
Keyword(s):  
Feeding Ecology ◽  
Trophic Position ◽  
Stomach Contents ◽  
Size Class ◽  
Relative Importance ◽  
Central Mediterranean ◽  
Gulf Of Gabes ◽  
Gulf Of Gabès ◽  
Index Of Relative Importance ◽  
Three Factor

The present study investigated the feeding ecology of the piked spurdog (Squalus megalops) in the Gulf of Gabès (Tunisia) with regard to sex, size class and season. A study of stomach contents from the 630 individuals examined showed that the species consumed teleosts (percentage index of relative importance (%IRI)=80.32), cephalopods (%IRI=11.96) and crustaceans (%IRI=7.68). A three-factor multivariate analysis of variance (MANOVA) demonstrated significant differences in diet related to size, season and sex. Trophic position analysis revealed that S. megalops is a secondary consumer throughout its life. Quantitative analysis indicated that the species is a generalist feeder with an ontogenetic change in preferred prey from crustaceans to teleosts. The niche breadths of S. megalops in both sexes were broad.

Feeding habits ofEucinostomus entomelasandMicropogonias megalopsin Las Guasimas lagoon Gulf of California

2014 ◽  
Vol 94 (8) ◽  
pp. 1721-1729
Author(s):  
Dana I. Arizmendi-Rodríguez ◽  
J. López-Martínez ◽  
E. Herrera-Valdivia
Keyword(s):  
Fish Species ◽  
Gulf Of California ◽  
Feeding Habits ◽  
Diet Breadth ◽  
Dark Spot ◽  
Relative Importance ◽  
Index Of Relative Importance ◽  
Trophic Overlap ◽  
Taxonomic Groups ◽  
Prey Items

The trophic spectrum of bothEucinostomus entomelasandMicropogonias megalops, the two most abundant fish species in Laguna Las Guásimas, Sonora, México is described in our study. A total of 21 types of prey were identified belonging to seven taxonomic groups (Crustacea, Mollusca, Annelida, Rhodophyta, Copepoda, Echinodermata and Chordata) to analyse the feeding spectra and diet breadth. The preferred prey items ofEucinostomus entomelas(Dark-spot mojarra) were Polichaeta (index of relative importance = 46.7%), followed by bivalves(36.6%), andLuidia columbia (5.6%), while those ofMicropogonias megalops(Bigeye croaker) were Portunidae (22.8%) followed by Gammaridae (20.55%) and Crustacea (18.37%). The trophic spectrum for maleE. entomelawas composed of Bivalvia and Polychaeta. Both predators showed low values in diet breadth (E. entomelas(Levin's indexBi = 0.14) andM. megalops(Levins's indexBi = 0.43)). The low trophic overlap (Cλ = 0.14) between predators suggests that both fish are not competing with each other for food resources in Laguna Las Guásimas.

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.

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.

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