Food resource partitioning between two sympatric temperate wrasses

2017 ◽  
Vol 68 (12) ◽  
pp. 2324 ◽  
Author(s):  
Mauro Sinopoli ◽  
Renato Chemello ◽  
Antonino Vaccaro ◽  
Marco Milazzo
Keyword(s):  
Resource Use ◽  
Prey Availability ◽  
Atlantic Coast ◽  
Food Resource ◽  
Stomach Contents ◽  
Food Resources ◽  
Sea Bottom ◽  
Over Dispersion ◽  
Labrid Species ◽  
Food Resource Partitioning

The present study analysed two sympatric wrasses, Thalassoma pavo and Coris julis, with similar sizes and morphologies, that are widespread in the reef habitats of the Mediterranean and the eastern Atlantic coast. Ocean warming has induced the northward movement of T. pavo, whereas C. julis has been moving to deeper habitats. In addition, under conditions of high slope of the sea bottom, T. pavo occupies shallow habitats and C. julis is in greater abundance in deeper habitats. By investigating stomach contents and prey availability in the benthos, we assessed whether the two wrasses exploit food resources by choosing different prey within the same habitat both under co-existence and segregation conditions. The results showed that T. pavo mainly feeds on gammarids and sipunculids, whereas C. julis mainly feeds on Alvania spp. and Paguroidea. The two wrasses also showed an intrinsic partitioning of food resources, independently of the condition of co-existence or segregation and benthic prey availability in the environment. The two wrasses fall in the ‘over dispersion of resource use’ model, in which species share numerous niche dimensions in a variable manner. Our findings may contribute to exclude a greater trophic competition between these labrid species in a projected warming scenario.

scholarly journals Aquatic insects as the main food resource of fish the community in a Neotropical reservoir

2009 ◽  
Vol 7 (4) ◽  
pp. 701-708 ◽  
Author(s):  
Ana Paula Vidotto-Magnoni ◽  
Edmir Daniel Carvalho
Keyword(s):  
Aquatic Insects ◽  
Food Resource ◽  
Gravimetric Method ◽  
Stomach Contents ◽  
Food Resources ◽  
Food Category ◽  
Main Food ◽  
Tietê River ◽  
Two Samples ◽  
Terrestrial Insects

We evaluated the feeding of fish species of the Nova Avanhandava Reservoir, low Tietê River, São Paulo State, Brazil. Fishes were collected in two stretches of the reservoir: Santa Bárbara (14 samples) and Bonito (two samples) between September 2002 and March 2004, using gill and seining nets. The results of stomach contents analysis were expressed with the frequency of occurrence and gravimetric method, combined in the Alimentary Index (AI). The 20 species studied consumed 52 food items, grouped in 10 food categories: aquatic insects, terrestrial insects, crustaceans, fish, macroinvertebrates, microcrustaceans, algae, vegetal matter, detritus/sediment and scales. The aquatic insects (mainly Chironomidae, Odonata and Ephemeroptera) were the most common food resources, consumed by 18 species. The diet composition of the community (species grouped) indicated that the dominant food category in the diet of fishes was aquatic insects (AI = 77.6%), followed by crustaceans (AI = 7.1%). Four trophic guilds were identified according a cluster analysis (Pearson distance): insectivorous (10 species), omnivorous (4 species), detritivorous (3 species) and piscivorous/carcinophagous (3 species). Despite the highest number of species, the insectivorous guild was responsible for more than 80% in captures in number and biomass (CPUEn and CPUEb). The low values of niche breadth presented by all species, along with the low values of diet overlap between species pairs indicate a high degree of food resources partitioning among species. The aquatic insects, despite being the main food resource of insectivorous fishes, also complemented the diet of other species, which demonstrate the importance of this food resource for the fish community, sustaining a high diversity, abundance and biomass of fishes.

FOOD PARTITIONING AMONG FISHES IN PAHANG RIVER-ESTUARY, MALAYSIA

2015 ◽  
Vol 77 (25) ◽  
Author(s):  
Azfar, A. M. ◽  
Jalal K. C. A. ◽  
Siti-Waznah, A.
Keyword(s):  
Food Resource ◽  
River Estuary ◽  
Stomach Contents ◽  
Monsoon Period ◽  
Fish Food ◽  
Microbial Decomposition ◽  
Plant Parts ◽  
Food And Feeding ◽  
Food Partitioning ◽  
Food Resource Partitioning

A study was conducted on the food resource partitioning among fish species in Pahang River-estuary from 2010-2013 during pre-monsoon and post-monsoon period. The area was divided in three strata (upstream, downstream and middle zone), based on environmental features. Stomach contents of all species present were analyzed. From 138 of total stomach analyzed, 24 of them were empty and 114 were with food. From the analysis of prey in the stomachs, various kinds of food items consumed by the different size of fishes included phytoplankton, zooplankton, unidentified materials, fish, fish parts, shrimp, shrimp parts, crab, crab parts, plant parts, mollusk and detritus. Detritus consisted of all types of biogenic materials in various stages of microbial decomposition. Different fishes consume different types of food and feeding habit of fishes varies from season to season. From the percentage of number and occurrence of food resources, zooplankton are important in their own right as a major component of fish diets and are especially important to small and young individuals, even for the detrivore. Nevertheless, it represents an important trophic resource for fish food web of Pahang River-estuary.

Feeding Strategies and Partition of Food Resources in Deep-Water Decapod Crustaceans (400–2300 m)

1998 ◽  
Vol 78 (2) ◽  
pp. 509-524 ◽  
Author(s):  
Joan E. Cartes
Keyword(s):  
Resource Partitioning ◽  
Feeding Strategy ◽  
Food Resource ◽  
Progressive Increase ◽  
Western Mediterranean ◽  
Food Resources ◽  
Feeding Strategies ◽  
Dietary Overlap ◽  
Decapod Crustaceans ◽  
Food Resource Partitioning

Food resource partitioning and trends in feeding strategies were examined in 3882 individual decapod crustaceans collected from 1989 to 1990, using bottom trawls at depths between 380 and 2261 m in the Catalan Sea (western Mediterranean). The vertical distribution of available food resources near the bottom was the most important factor responsible for food resource partitioning among bathyal decapod crustaceans by depth stratum and season. Decapods were assigned to five different trophic groups according to the food resource exploited and feeding strategy employed (macroplankton feeders, macroplankton-epibenthic feeders, epibenthic feeders, epibenthic-endobenthic feeders, and deposit feeders). There was little dietary overlap, indicating that species did partition the available resources. Overall, dietary overlap values among species increased with depth. Although a trend to increase H’ values for diets with depth was observed, this was not significant (P < 0.10), whereas differences in the percentage of empty stomachs and the frequency of foraminiferans and pteropods in the foreguts increased significantly (P < 0.05) with depth. This last result is indicative of a progressive increase in the importance of deposit feeding in decapod crustaceans as depth increases.

scholarly journals Specialist predation covaries with colour polymorphism in tawny owls

2021 ◽  
Vol 75 (3) ◽  
Author(s):  
Patrik Karell ◽  
Kio Kohonen ◽  
Katja Koskenpato
Keyword(s):  
Small Mammals ◽  
Prey Availability ◽  
Food Resource ◽  
Food Resources ◽  
Colour Polymorphism ◽  
Generalist Predator ◽  
Colour Morph ◽  
Tawny Owl ◽  
Main Prey ◽  
Main Food

Abstract Understanding intraspecific phenotypic variation in prey specialisation can help to predict how long-term changes in prey availability affect the viability of these phenotypes and their persistence. Generalists are favoured when the main food resources are unpredictable compared to specialists, which track the availability of the main prey and are more vulnerable to changes in the main food resource. Intraspecific heritable melanin-based colour polymorphism is considered to reflect adaptations to different environments. We studied colour morph-specific diet specialisation in a generalist predator, tawny owl (Strix aluco), during offspring food provisioning in relation to mammal prey density. We hypothesised that the grey morph, with higher fitness than the brown in Northern boreal conditions, is more specialised in mammalian prey than the brown morph, which in turn has higher fitness than the grey in the temperate zone. We found a higher diversity of prey delivered to the nest by brown fathers compared to grey ones, which also depended on the overall mammalian prey availability. Brown fathers provided proportionally fewer mammalian prey than grey in poor, but not in favourable mammal prey years. Our results suggest that the brown morph is more generalistic and reacts more strongly to variations in food supply than the grey morph, which may be a beneficial strategy in an unpredictable environment caused by environmental degradation. Significance statement Diet choice of a species may vary depending on fluctuations in the abundance of their food resource, but also within a population, there can be adaptations to use different food resources. The tawny owl exhibits a grey and a reddish-brown colour morph and is considered a generalist predator eating both mammal and bird prey. We find that the diet of the reddish-brown morph is more diverse than that of the grey. When the tawny owls’ main prey, small mammals, are abundant both colour morphs prey on mammals, but in years with less small mammals, the reddish-brown morph is more prone of switching to small bird predation than the grey. The generalist strategy of the brown morph is likely to be more favourable than a stricter specialisation in small mammals of the grey under recently reoccurring irregularities in small mammal dynamics.

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 Diet seasonality and food overlap of the fish assemblage in a pantanal pond

2008 ◽  
Vol 6 (4) ◽  
pp. 567-576 ◽  
Author(s):  
Gisele Caroline Novakowski ◽  
Norma Segatti Hahn ◽  
Rosemara Fugi
Keyword(s):  
Fish Assemblage ◽  
Food Resource ◽  
Fish Fauna ◽  
Diet Breadth ◽  
Food Resources ◽  
Dry Season ◽  
Trophic Guilds ◽  
Trophic Specialization ◽  
Mato Grosso ◽  
Mean Values

We assessed the trophic structure of the fish fauna in Sinhá Mariana pond, Mato Grosso State, from March 2000 to February 2001. The aim was to determine the feeding patterns of the fish species during the rainy and dry seasons. The diets of 26 species (1,294 stomach contents) were determined by the volumetric method. Insects and fish were the most important food resources: insects were the dominant food of 23% and 27% of the species, respectively, in the rainy and dry season, and fish was the dominant item for 31% of the species in both seasons. Cluster analysis (Euclidean Distance) identified seven trophic guilds in the rainy season (detritivores, herbivores, insectivores, lepidophages, omnivores, piscivores and planktivores), and five trophic guilds in the dry season (detritivores, insectivores, lepidophages, omnivores and piscivores). The smallest mean values of diet breadth were observed for the specialist guilds (detritivores, lepidophages and piscivores), in both seasons. The widest means for diet breadth were observed for the omnivores, regardless of the season. In general, there was no seasonal variation in feeding overlap among the species studied. At the community level, diet overlap values between species were low (< 0.4) for 80% of the pairs in each season, suggesting wide partitioning of the food resource. The fish assemblage showed a tendency toward trophic specialization, regardless of the season, although several species changed their diets. We might consider two non-excludent hypothesis: that there is no pattern on the use of seasonal food resources and/or probably there are several patterns, because each one is based on characteristics of the studied site and the taxonomic composition of the resident species.

scholarly journals Gut content analysis of cattle egrets (Bubulcus ibis) in Asam Kumbang Crocodile Park, North Sumatra

2021 ◽  
Vol 912 (1) ◽  
pp. 012105
Author(s):  
E Jumilawaty ◽  
N Namira ◽  
A Anggelicha ◽  
A Hartanto
Keyword(s):  
Content Analysis ◽  
Prey Species ◽  
Prey Availability ◽  
Biological Control Agent ◽  
Food Resource ◽  
Control Agent ◽  
Gut Content Analysis ◽  
Gut Content ◽  
Dominant Group ◽  
Bubulcus Ibis

Abstract Cattle egret (Bubulcus ibis) is a widespread avian species inhabiting a variety of natural and artificial sites. Asam Kumbang Crocodile Park is one of establishments that occupied some portions of B. ibis habitat with no recent information on the food resource and prey availability for the viability of B. ibis. To this aim, we collected 10 random individuals of B. ibis to be sacrificed for gut content analysis of prey species. A total of 19 taxa was found as prey items in the gut of B. ibis with the dominant group from insects (Orthoptera, Scolopendromorpha). The diversity of prey species was categorized as moderate with intraspecific diet variation which formed four guilds that fed on specific taxa namely Group 1 (Haplotaxida, Lepidoptera, Anurans), Group 2 (Blattodea, Coleoptera, Araneae), Group 3 (Orthoptera, Scolopendromorpha); and Group 4 (Dermaptera, Squamata). Oxya chinensis and Oxya velox are important rice grasshopper pests that were also found in the gut of B. ibis reflecting their potential function as biological control agent.

scholarly journals Patterns of food resource use by two congeneric species of piranhas (Serrasalmus) on the upper Paraná river floodplain

2003 ◽  
Vol 63 (2) ◽  
pp. 177-182 ◽  
Author(s):  
C. S. Agostinho ◽  
N. S. Hahn ◽  
E. E. Marques
Keyword(s):  
Resource Use ◽  
Native Species ◽  
Feeding Strategy ◽  
Food Resource ◽  
Paraná River ◽  
Activity Period ◽  
Parana River ◽  
Invading Species ◽  
Upper Paraná River Floodplain ◽  
Upper Paraná River

Serrasalmus marginatus invaded the Upper Paraná River after construction of the Itaipu Dam in November 1982. This was followed by a reduction in abundance of the native species S. spilopleura. Analysis of the pattern of food resource use revealed that both species employ the same feeding strategy, eating mainly fish (whole fish or muscle fragments) and fins bitten off their prey. The diurnal activity period and the feeding rhythm were better-defined in S. marginatus. For young individuals of both species, food was taken in a significantly discontinuous manner (F = 2.83; p < 0.05 and F = 13.25; p < 0.05), with a peak at 4 p.m. Ontogenetic differences in diet, the strong feeding overlap of larger individuals of S. marginatus and smaller individuals of S. spilopleura, and the aggressiveness of S. marginatus in establishing feeding territories may have contributed to the success of the invading species.

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