scholarly journals Diet-morphology relationship in the stream-dwelling characid Deuterodon stigmaturus (Gomes, 1947) (Characiformes: Characidae) is partially conditioned by ontogenetic development

2016 ◽  
Vol 14 (2) ◽  
Author(s):  
Renato Bolson Dala-Corte ◽  
Eliane Regina da Silva ◽  
Clarice Bernhardt Fialho
Keyword(s):  
Body Size ◽  
Diet Composition ◽  
Aquatic Invertebrates ◽  
Trophic Niche ◽  
Ontogenetic Development ◽  
Filamentous Algae ◽  
Terrestrial Plants ◽  
Food Items ◽  
Interindividual Variations ◽  
Intestine Length

ABSTRACT We tested whether interindividual variations in diet composition within a population of Deuterodon stigmaturus can be explained by morphological differences between individuals, and whether diet-morphology relationships are dependent on the ontogenetic development. We analyzed diet of 75 specimens sampled in a coastal stream of Southern Brazil. Variation in stomach content was summarized with a Principal Coordinate Analysis (PCoA). The retained PCoA axes were tested as response to standard length (SL), and to values of intestine length (IL) and mouth length (ML) independent of body size, using linear mixed-effects models (LMM). The most consumed food items by D. stigmaturus were filamentous algae (41%), terrestrial plants (20.3%), detritus (12%), and aquatic invertebrates (8.8%). The LMMs showed that SL was positively related to consumption of terrestrial plants, whereas IL independent of SL was negatively related to aquatic invertebrates and positively related to filamentous algae. When body sized was held constant, ML was not related to diet variation. Interindividual diet differences conditioned to body size suggest that individuals shift their trophic niche and function in the ecosystem along the ontogenetic development. Relationships between intestine length and diet composition suggest interindividual differences in foraging ability and digestibility of distinct food items.

scholarly journals Do algae blooms dilute the risk of trematode infections in threespine sticklebacks?

2015 ◽  
Vol 61 (6) ◽  
pp. 991-995 ◽  
Author(s):  
Alexandre Budria ◽  
Ulrika Candolin
Keyword(s):  
Body Size ◽  
Gasterosteus Aculeatus ◽  
Infected Fish ◽  
The Body ◽  
Filamentous Algae ◽  
Intermediate Hosts ◽  
Diplostomum Pseudospathaceum ◽  
The Difference ◽  
Trematode Infections ◽  
Macro Algae

Abstract Human-induced growth of macro-algae is often assumed to increase trematode infections in fishes by increasing the abundance and condition of the parasite’s intermediate host – snails – as this can boost the release of trematode larvae, cercariae, from the intermediate hosts. However, macro-algae can also impose barriers to the transmission of cercariae and reduce infections. We investigated whether an increased growth of filamentous algae affects the transmission of Diplostomum pseudospathaceum cercariae to the threespine stickleback Gasterosteus aculeatus, a common fish in eutrophied shallow waters. We exposed sticklebacks to trematode cercariae in the absence and presence of artificial filamentous algae, and recorded effects on the proportion of sticklebacks infected and the number of encysted metacercariae per fish. No significant effect of artificial algae on cercariae transmission was detected. However, the body size and the sex of the sticklebacks were strongly correlated with the number of encysted metacercariae per infected fish, with females and larger individuals being more infected. We discuss different factors that could have caused the difference in parasite transmission, including sex-related differences in body size and behaviour of sticklebacks.

scholarly journals Diet composition and feeding habits of the eyespot skate, Atlantoraja cyclophora (Elasmobranchii: Arhynchobatidae), off Uruguay and northern Argentina

2016 ◽  
Vol 14 (3) ◽  
Author(s):  
Santiago A. Barbini ◽  
Luis O. Lucifora
Keyword(s):  
Body Size ◽  
Diet Composition ◽  
Prey Size ◽  
Prey Availability ◽  
Feeding Habits ◽  
Warm Season ◽  
Cold Season ◽  
The North ◽  
Multiple Hypothesis ◽  
Modelling Approach

ABSTRACT The eyespot skate, Atlantoraja cyclophora, is an endemic species from the southwestern Atlantic, occurring from Rio de Janeiro, Brazil, to northern Patagonia, Argentina. The feeding habits of this species, from off Uruguay and north Argentina, were evaluated using a multiple hypothesis modelling approach. In general, the diet was composed mainly of decapod crustaceans, followed by teleost fishes. Molluscs, mysidaceans, amphipods, isopods, lancelets and elasmobranchs were consumed in lower proportion. The consumption of shrimps drecreased with increasing body size of A. cyclophora. On the other hand, the consumption of teleosts increased with body size. Mature individuals preyed more heavily on crabs than immature individuals. Teleosts were consumed more in the south region (34º - 38ºS) and crabs in the north region (38º - 41ºS). Shrimps were eaten more in the warm season than in the cold season. Prey size increased with increasing body size of A. cyclophora , but large individuals also consumed small teleosts and crabs. Atlantoraja cyclophora has demersal-benthic feeding habits, shifts its diet with increasing body size and in response to seasonal and regional changes in prey availability and distribution.

scholarly journals Foraging behaviour and performance of steers from two local breeds (Asturian Valley and Asturian Mountain) grazing in Cantabrian (N Spain) summer pastures

2019 ◽  
Vol 17 (1) ◽  
pp. e0601
Author(s):  
Alicia Román-Trufero ◽  
Antonio Martínez ◽  
Luis M. M. Ferreira ◽  
Valentín García-Prieto ◽  
Rocío Rosa-García ◽  
...  
Keyword(s):  
Body Weight ◽  
Body Size ◽  
Diet Composition ◽  
Foraging Behaviour ◽  
Meat Production ◽  
Market Demand ◽  
Nutrient Requirements ◽  
Northern Spain ◽  
Sward Height ◽  
And Performance

Steer meat production in northern Spain is deficient to attend market demand. This research aimed to compare the foraging behaviour and production of yearling steers from two local breeds differing in body weight (BW), Asturian Valley (AV, 372 kg) and Asturian Mountain (AM, 307 kg), grazing in summer pastures consisting of 70% grassland and 30% heathland. Bodyweight gains from a total of 42 steers were recorded during four grazing seasons (from June to October). In two years, in July and September, plant community selection and diet composition were estimated by direct observation and using faecal markers, respectively. Grazing time increased from July to September (488 vs. 557 min/day; p<0.001) as sward height in the grassland decreased. Although AV steers grazed proportionally for longer on herbaceous pastures than AM steers (81.3 vs. 73.3%; p<0.05), no differences between breeds were found in diet composition. AM steers showed greater mean daily BW gains than AV steers (252 vs. 133 g/day; p<0.01). From June to August, steers from both breeds gained BW (487 vs. 360 g/day for AM and AV, respectively; p<0.01), but thereafter BW gains decreased (120 vs. –12 g/day for AM and AV, respectively; p<0.05), because of reduced availability of grassland herbage. Yearling steers from AM breed seem to be better suited to mountain conditions than those from AV breed, probably because of their smaller body size and lower total nutrient requirements for maintenance.

scholarly journals Diet Composition and Seasonal Fluctuations in the Feeding Habit of Snow Barbel (Schizothorax plagiostomus) in River Indus, Pakistan

2018 ◽  
Vol 46 (1) ◽  
pp. 8
Author(s):  
Muhammad Qayash Khan ◽  
Muhammad Zubair Anjum ◽  
Shamim Akhter ◽  
Irfan Khattak ◽  
Abid Ali
Keyword(s):  
Diet Composition ◽  
Feeding Activity ◽  
Fish Fauna ◽  
Feeding Habit ◽  
Gut Contents ◽  
Catch Per Unit Effort ◽  
Food Items ◽  
Unit Effort ◽  
Significant Difference ◽  
River Indus

Background:Schizothorax plagiostomus is widely distributed in river Indus and is most important food fish in Pakistan. The feeding habit of fish is directly related to the size of fish, its metabolic rate and environmental temperature. The accurate description of fish diet and feeding habit is a very important aspect in fisheries management for the purpose of species conservation, breeding and culture. The present work was aimed to investigate the specie abundance, the diet composition and seasonal variations in the feeding habit of Snow barbell Schizothorax plagiostomus.Materials, Methods & Results: A total of 1799 fish specimens were caught at the confluence of six tributaries along river Indus at Indus Kohistan, northeastern Pakistan. The fish were collected by 5-panels of gill net during first week of each month. The site specific Catch Per Unit Effort (CPUE) and season specific CPUE of fish fauna were assessed. For the gut content analysis 240 samples (99 male and 141 females) of S. plagiostomus were selected on monthly basis. Frequency of occurrence method and volumetric method were applied to record the different food items in the gut of S. plagiostomus. The physico-chemical parameters, NO3 concentration and dissolved Co2 of water from different localities of river Indus were recorded month wise by Hach sensION 156 meter, Horiba LAQUA Nitrate Meter and EA80 meter respectively. Significant difference was observed in water temperature during the four seasons. Except alkalinity no other water parameter showed significant variation across different localities. The results showed that highest Mean CPUE was observed for Darel Stream (0.55) and lowest for Jalkot stream (0.26). Peak abundance of fish was recorded in the month of November with a mean catch of 44.50, mean CPUE of 0.74 and mean Kruskal-Wallis rank value of 63.25. Spirogyra and Ulothrix occurred as maximum food items in the gut of S. plagiostomus during summer while their minimum amount occurred during autumn. According to the ranking index spirogyra and ulothrix ranked higher with significant difference in comparison to other food items. The results showed that S. plagiostomus is phytophagous in its feeding habit, which consumed mainly algae attached to stones and pebbles during the whole year. However, the presence of some secondary items such as animal matter, detritus, sand and mud might be due to the distinct availabilities of food along the seasons. The highest feeding activity of S. plagiostomus was recorded during summer while the lowest one occurred during autumn, spring and winter. Discussion: Catch per unit effort (CPUE) is an indirect measure of the abundance of a target species. It is used as an index of stock abundance in fisheries and conservation biology. During the study low fish fauna was found in River Indus as reported previously. Majority of the fish occurred in snow fed river tributaries in the study area as these tributaries are comparatively less turbulent. Previous studies have also recorded that Schizothoracine generally prefer clean waters. The present findings of gut contents analysis showed clearly that S. plagiostomus is a phytophagous fish which scrap and consumed spirogyra and ulothrix attached to stones and pebbles. Earlier it was reported that mouth of S. plagiostomusis is inferior, wide, with deep lower jaw having keratinized cutting edge and the lower lip is folded and expanded with numerous papillae making it best suited for scrapping algae attached to stones and pebbles. The highest feeding activity was observed during warmer months as compared to cold months. S. plagiostomus spawn twice in a year in autumn and in spring. The highest feeding activity of S. plagiostomus seems to be link with a reflex of recovery strategy due to physiological process of gonadal development.

scholarly journals Diet composition of the raccoon dog (Nyctereutes procyonoides) and badger (Meles meles) in Czech Republic

2004 ◽  
Vol 52 (1) ◽  
pp. 81-90
Author(s):  
Hana Šuláková
Keyword(s):  
Protected Area ◽  
Diet Composition ◽  
Meles Meles ◽  
Relative Volume ◽  
Food Sources ◽  
Nyctereutes Procyonoides ◽  
Raccoon Dog ◽  
Food Items ◽  
Competition For Food ◽  
Frequency Occurrence

Diets of the raccoon dog and badger were studied in the Landscape Protected Area (LPA) Litovelské Pomoraví from 2000 to 2001 by collecting faeces from latrines during March – December every year. The relative volume and frequency occurrence of each food item in the feaces were calculated. Vertebrates and invertebrates constituted the bulk of the raccoon dog diet, while plants and invertebrates were most frequently eaten by the badger. Insecta and Rodentia were important to the raccoon dog, but it also consumed other food items. The raccoon dog was more omnivorous that the badger. Badger fed very frequently on plant material, raccoon dog, instead, frequently ate insects, especially beetles. In conclusion, the diet of the raccoon dog overlaps largely with that of badger, and some competition for food may occur between these species in the LPA Litovelské Pomoraví; however, their preferred food sources differ to some extent, which helps them to avoid competition.

scholarly journals Diet and nematode infection in Proceratoprhys boiei (Anura: Cycloramphidae) from two Atlantic rainforest remnants in Southeastern Brazil

2011 ◽  
Vol 83 (4) ◽  
pp. 1303-1312 ◽  
Author(s):  
Thaís Klaion ◽  
Mauricio Almeida-gomes ◽  
Luiz E. R. Tavares ◽  
Carlos F. D. Rocha ◽  
Monique Van Sluys
Keyword(s):  
Digestive Tract ◽  
Leaf Litter ◽  
Larval Stage ◽  
Diet Composition ◽  
Infection Intensity ◽  
Nematode Species ◽  
Helminth Fauna ◽  
Atlantic Rainforest ◽  
Southeastern Brazil ◽  
Food Items

Proceratophrys boiei is an endemic cycloramphid anuran inhabiting the leaf litter of Atlantic rainforests in Southeastern Brazil. We analyzed the whole digestive tract of 38 individuals of Proceratophrys boiei collected in two Atlantic Rainforest areas in the state of Rio de Janeiro, Brazil, to study the diet composition and the helminth fauna associated with this species. The main food items in P. boiei's diet were Coleoptera, Orthoptera and Blattaria. Five nematode species were found: Aplectana delirae, Cosmocerca parva, Oxyascaris oxyascaris, Physaloptera sp. (larval stage only) and an unidentified nematode. Overall prevalence was 71% and mean infection intensity was 7.3 ± 5.8 neatodes per individual.

Intraspecific variation in a lizard from the Central Mexican Plateau: intersexual differences in size and shape explored

2020 ◽  
Vol 131 (3) ◽  
pp. 656-666
Author(s):  
Abraham Lozano ◽  
Aurelio Ramírez-Bautista ◽  
Raciel Cruz-Elizalde
Keyword(s):  
Body Size ◽  
Trophic Niche ◽  
Size And Shape ◽  
Biomechanical Models ◽  
Tree Population ◽  
Morphological Adaptations ◽  
Selective Forces ◽  
Sceloporus Grammicus ◽  
Intraspecific Morphological Variation ◽  
Two Populations

Abstract Morphological adaptations of individuals are directly (or indirectly) determined by the environment. Depending on sex, these adaptations may vary in different ways, given that different selective forces may be operating on organisms. Here, we evaluate intraspecific morphological variation (size and shape) in two populations of Sceloporus grammicus that occur in different structural habitats (trees and rocks). No difference in overall body size was found between the two populations. However, strong differences were found in body shape; the tree population was characterized by having shorter hindlimb proportions than the rock population, which agrees with the theory of biomechanical models. Furthermore, our results show that this species is dimorphic in size and shape, both in sex and population effects. A review of the literature suggests that the large overall body size and relatively longer distal segments of males could be an advantage for defending their territory, and the observation that females had relatively longer head length may be related to trophic niche divergence; however, this remains to be tested. Detailed quantification of behaviour, performance and reproductive characteristics must be performed to shed light on the evolution of sexual dimorphism in this widely distributed species in Mexico.

Dietary strategy of a Pyrenean lizard, Iberolacerta aurelioi, living in a poor resources alpine environment

2008 ◽  
Vol 29 (3) ◽  
pp. 329-336 ◽  
Author(s):  
Teresa García Díez ◽  
José Ángel Hernández-Estévez ◽  
Valentín Pérez-Mellado ◽  
Fèlix Amat
Keyword(s):  
Diet Composition ◽  
Trophic Niche ◽  
High Mountain ◽  
Faecal Pellets ◽  
Rocky Slope ◽  
Mountain Habitats ◽  
Availability Constraints ◽  
Dietary Strategy ◽  
Cannibalistic Behaviour ◽  
Low Amplitude

Abstract We report the first study of diet composition of a Pyrenean lizard of the genus Iberolacerta, the Aurelio's lizard, I. aurelioi, living in an alpine rocky slope at 2300 m of altitude in Andorra. Diet composition was studied during two years from 289 faecal pellets containing 966 prey items. Number of prey per pellet shows annual, seasonal and sexual differences. Diet of the species is poorly diverse, mainly dominated by insects, but we find clear evidences of opportunistic cannibalism based on the presence of toes and scales in feces. In addition, we detected minor sexual, annual and month differences in prey presence and abundance. Low amplitude of trophic niche width and prey diversity, as well as predation on clumped prey and cannibalistic behaviour suggest that Iberolacerta aurelioi has a remarkable dietary strategy in response to strong thermal and food availability constraints at high mountain habitats.

scholarly journals Ecomorphology and food habits of teleost fishes Trachinotus carolinus (Teleostei: Carangidae) and Menticirrhus littoralis (Teleostei: Sciaenidae), inhabiting the surf zone off Niterói, Rio de Janeiro, Brazil

2010 ◽  
Vol 58 (spe4) ◽  
pp. 1-9 ◽  
Author(s):  
Luana Prestrelo Palmeira ◽  
Cassiano Monteiro-Neto
Keyword(s):  
Fish Species ◽  
Food Habits ◽  
Diet Composition ◽  
Surf Zone ◽  
Fish Larvae ◽  
Sandy Beaches ◽  
Size Class ◽  
Class I ◽  
Teleost Fishes ◽  
Food Items

The ecomorphology and food habits of juvenile Trachinotus carolinus and Menticirrhus littoralis caught in the surf zone of sandy beaches in Niterói, RJ, were investigated between July 2006 and May 2007. These fish species differ morphologically, but present similarities in their diet composition suggest some slight overlapping in their diet. The importance of food items was assessed using Kawakami and Vazzoler's feeding index. Morphometric variables were recorded to correlate with the diet composition of the different size classes for each species. A total of 210 fishes (Trachinotus carolinus - 122, Menticirrhus littoralis - 88), ranging between 24.2 mm and 112 mm total length, were analyzed, but the stomachs of only 84.8% of them contained food. Trachinotus carolinus presented mysids, Polychaetes and Emerita spp. as the predominant items in their diet. Formicidae and Isopoda were the most important items for class I individuals, whereas mysids and Emerita spp. were important for classes II and III. Class I individuals also showed smaller sized prey (amphipods and isopods) and clupeid fish larvae in their diet. Emerita spp. dominated the food items of Menticirrhus littoralis regardless of the size class. Polychaetes, the second most important item was better represented in class sizes II and III. The main morphometric variable correlated with such differences included mouth position and diameter of the eye.

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