Changes in the diet composition of Pygmy Cormorant Phalacrocorax pygmeus on Skadar lake (Southern Montenegro)

Changes in the diet composition of Pygmy Cormorant Phalacrocorax pygmeus on Skadar lake (Southern Montenegro) Diet changes of Pygmy Cormorant Phalacrocorax pygmeus, a piscivorous bird feeding primarily on fish up to 15 cm long, were studied on Skadar Lake. The breeding population on the lake was estimated at over 2,000 pairs in 2005 and 1,260 pairs in 2006, comprising about 5-8% of the regional population of SE Europe & Turkey. The first diet analysis, based on stomach contents of specimens hunted in the course of the breeding season, was carried out in the period 1973-1975 in order to identify the influence of the birds on commercial fishery. Further samples of regurgitated or accidentally dropped food items during the feeding of nestlings were collected and analyzed in the 2006 breeding season. Results from both periods are presented and changes in diet composition in the course of over 30 years are discussed. Between 1973-1975 and 2006, the Pygmy Cormorant's diet on Skadar Lake changed drastically. Only one fish species, Rudd Scardinius knezevici, was found to be common to both study periods. Pygmy Cormorant's diet in the period 1973-1975 consisted of 11 fish species (N = 224 specimens), belonging to five families. The most abundant fish species were Roach Rutilus ohridanus and Albanian Roach Pachychilon pictum. Diet analysis in 2006 revealed only six species (N = 98 specimens) from two families, and also showed that the introduced Goldfish Carassius auratus became a major food source for Pygmy Cormorant, constituting 84.7% of the total specimen number. Age class analysis of Goldfish items revealed that juvenile specimens (45-90 mm) comprised 89.0% of the total Goldfish compound. The study confirms that the Pygmy Cormorant is not a species-specific hunter and suggests it is not affected by the changes in composition of fish community in the littoral zone of the lake. Fish consumption by Pygmy Cormorants on Skadar Lake in 2006 was estimated at 45 t during the most intensive foraging period (June-August).

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Diet composition and overlap for 43 fishes in the North Aegean Sea, Greece

Acta Adriatica ◽

10.32582/aa.58.1.10 ◽

2017 ◽

Vol 58 (1) ◽

pp. 125-136 ◽

Cited By ~ 2

Author(s):

Paraskevi K. Karachle

Keyword(s):

Fish Species ◽

Plant Material ◽

Diet Composition ◽

Aegean Sea ◽

The Other ◽

Diet Analysis ◽

Habitat Segregation ◽

The North ◽

North Aegean ◽

North Aegean Sea

This study presents the diet composition of 43 of some of the most abundant fish species from the North Aegean Sea, Greece. According to the diet analysis and fractional trophic level previously reported in the literature, 20 of the studied species were omnivores with a preference for animals and the other half were carnivores (15 with preference for fish and Cephalopoda, and seven with preference for fish and Decapoda), whereas Parablennius gattorugine was the only recorded omnivore with a preference for plant material. Finally, according to the results of Schoener’s index, diet overlap between species was recorded in a small number of cases (33 out of the 903 pairs examined). Yet, competition among diet-overlapping species may be minimised by either morphological differentiations and/or habitat segregation.

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Diet and feeding of fish from Grande River, located below the Volta Grande Reservoir, MG-SP

Brazilian Journal of Biology ◽

10.1590/s1519-69842005000300002 ◽

2005 ◽

Vol 65 (3) ◽

pp. 377-385 ◽

Cited By ~ 10

Author(s):

P. M. Andrade ◽

F. M. S. Braga

Keyword(s):

Fish Species ◽

Aquatic Macrophytes ◽

Diet Composition ◽

Feeding Habits ◽

Stomach Contents ◽

Tropical Fish ◽

Volume Number ◽

Classic Model ◽

Common Basis ◽

Pimelodus Maculatus

We compare the classic model of feeding of tropical fish by means of six bimonthly samplings using gillnets of varying mesh sizes that were inspected every twelve hours throughout a forty-eight hour period. The stomachs of the fish caught were classified in three categories according to quantity of food found. The amount of fat in the visceral cavity with respect to the energetic reserve deposition was also studied. The relative frequencies of the different categories of stomach repletion and fat deposition were examined for patterns of feeding seasonality. The stomachs considered full were examined to record diet composition. To assess the relative importance of the different food resources, we applied Feeding Importance Degree (FID), which is a useful index when difficulties exist in determining a common basis for volume, number, or weight of a given food item in different species, a common problem when dealing with fish species having different feeding habits. The fish species whose stomach contents were analyzed using the FID index were Serrasalmus spilopleura (Characidae), L. prolixa (Loricaridae), Schizodon nasutus (Anostomidae), and Pimelodus maculatus (Pimelodidae). Our findings indicate some contrasting elements , in dietary composition in relation to the classic model for tropical rivers. These factors include the importance of aquatic macrophytes, the lack of piscivorous species, and a lesser presence of allochthonous vegetation in the diet of the species studied.

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Diet composition of abundant fish species in the shallow waters of the Todos os Santos Bay, Bahia, Brazil

Acta Scientiarum Biological Sciences ◽

10.4025/actascibiolsci.v43i1.52230 ◽

2021 ◽

Vol 43 ◽

pp. e52230

Author(s):

Rafael Lima Oliveira ◽

Leonardo Evangelista Moraes ◽

Alexandre Clistenes de Alcântara Santos

Keyword(s):

Fish Species ◽

Diet Composition ◽

River Estuary ◽

Stomach Contents ◽

Environmental Parameters ◽

Abundant Species ◽

Shallow Waters ◽

Trophic Guilds ◽

Food Items ◽

Ecological Importance

Coastal habitats have great ecological importance with estuarine environments providing feeding sites for many fish species, especially during juvenile life stages. This study investigates the diet composition and trophic guild organization of the common and abundant ichthyofauna in shallow areas of the Todos os Santos Bay (TSB), Bahia, Brazil, and their relationships with environmental parameters. Six fish sampling campaigns were carried out in the shallow zones (infralittoral) of the Paraguaçu River estuary which encompasses the inner and outer (marine exposure) reaches of the TSB. The stomach contents of 1231 individuals belonging to common and abundant species were examined. A total of 32 food items were identified and fish were into four trophic guilds: detritivores, zoobenthivores I, zoobenthivores II, and zooplanktivores. The relationship between the guilds and environmental parameters showed that zoobenthivores II and zooplanktivores guilds had a positive relationship with salinity and pH, explaining 86% of data variability, though only the salinity variable was significant. This study provides basic information about the diet composition of common and abundant species in the TSB and their organization into trophic guilds. In addition, demonstrates that shallow waters fish across all guilds have broadly similar diets, comprising food items that are usually associated with bottom waters.

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Diet of a rare Canadian fish species, Carmine Shiner (Notropis percobromus) in the Birch River, Manitoba, Canada

The Canadian Field-Naturalist ◽

10.22621/cfn.v134i1.2301 ◽

2020 ◽

Vol 134 (1) ◽

pp. 64-70

Author(s):

Eva C. Enders ◽

Tharshinidevy Nagalingam ◽

Amanda L. Caskenette ◽

Tyana A. Rudolfsen ◽

Colin Charles ◽

...

Keyword(s):

At Risk ◽

Fish Species ◽

Aquatic Insects ◽

Diet Composition ◽

Temporal Trends ◽

Stomach Contents ◽

Open Water ◽

Species At Risk ◽

Conservation Actions ◽

Species At Risk Act

Due to its restricted occurrence and existing threats, Carmine Shiner (Notropis percobromus) has been listed as threatened under the Canadian Species at Risk Act. Little is known about Carmine Shiner biology, and understanding its diet composition will help inform future conservation actions. Consequently, the aim of this study was to analyze the diet of Carmine Shiner. Fish were caught throughout the open water season using beach seines, and stomach contents were analyzed. Carmine Shiner feed on a variety of terrestrial and aquatic insects. Diets did not differ substantially between year classes, and we observed no clear temporal trends in diet composition.

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Otolith atlas of fish of the Sinos River

Brazilian Journal of Biology ◽

10.1590/1519-6984.11612 ◽

2014 ◽

Vol 74 (2) ◽

pp. 274-282 ◽

Cited By ~ 2

Author(s):

CQ. Bremm ◽

UH. Schulz

Keyword(s):

Calcium Carbonate ◽

Inner Ear ◽

Digestive Tract ◽

Fish Species ◽

Stomach Contents ◽

Species Specific

Otoliths are calcium carbonate structures located in the inner ear of fish; they are responsible for hearing and balance. The inner ear has three pairs of otoliths: the lapilli, the sagittae and the asterisci. The sagittae otoliths are the largest and their format is species-specific. Because of their composition, otoliths can resist to the digestive tract of ichthyophagous species, and they can be used as an important tool for identifying species of fish found in stomach contents. The purpose of this work is to provide a photographic guide of the sagittae otoliths of the main fish species from the Sinos River. This atlas consists of photographs of the sagittae otoliths of 36 species belonging to 15 families distributed in five orders.

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Bioaccumulation of mercury in fishes of Jagadishpur Reservoir, Nepal

Nepal Journal of Environmental Science ◽

10.3126/njes.v7i0.34370 ◽

2019 ◽

Vol 7 ◽

pp. 17-23

Author(s):

Prakash Acharya ◽

Chhatra Mani Sharma ◽

Shichang Kang ◽

Lekhendra Tripathee ◽

Junming Guo ◽

...

Keyword(s):

Fish Species ◽

Fish Community ◽

Food Resource ◽

Stomach Contents ◽

Stomach Content Analysis ◽

Trophic Levels ◽

Fish Length ◽

Mystus Vittatus ◽

Total Hg ◽

Food Resource Utilization

Stable isotope ratios of nitrogen (δ15N, ‰) and carbon (δ13C, ‰), accompanied by stomach contents were used to assess the food chain and trophic transfer of mercury in fifty-three marketable sized fish belonging to five species (Channa punctatus, Mystus vittatus, Nandus nandus, Puntius sophore and Xenentodon cancila) from the Jagadishpur Reservoir, Nepal. The highest total Hg concentration was found in X. cancila with an average of 800.42(±279.36) µg/kg exceeding the international marketing limit (500 mg/kg), a carnivorous species. However, except for some individuals of N. nandus, total Hg concentrations in other fish species in the present study were significantly lower than that limit. The fish community had at least two trophic levels (Δ15N > 5.6), C. punctatus with the highest and M. vittatus the lowest signatures of δ15N, which was also supported by the stomach content analysis. There was neither correlation between total Hg and δ15N nor connectivity in food resource utilization (based on δ13C), indicating no biomagnification among these fish species. In addition, Hg concentrations were not significantly correlated to total fish length in any of the species. Fish species in the present study have low Hg content accompanied by low biomagnification through the studied fish community.

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Trophic analysis of the fish community in the Ciénega Churince, Cuatro Ciénegas, Coahuila

10.7287/peerj.preprints.2154 ◽

2016 ◽

Author(s):

Ariana Hernández ◽

Hector S Espinosa-Pérez ◽

Valeria Souza

Keyword(s):

Fish Species ◽

Fish Community ◽

Stomach Contents ◽

Feeding Strategies ◽

Trophic Chain ◽

Fish Diets ◽

Average Linkage ◽

Linkage Method ◽

Index Of Relative Importance ◽

Trophic Analysis

The fish community in the Churince system includes endemic, native and introduced species. Fish diets were analysed in order to evaluate the tropho-dynamics of the community. Nine sampling campaigns were carried out between February 2011 and May 2014, and 556 specimens of nine fish species were collected. Stomach contents were analysed using the Index of Relative Importance (IRI) and the Index of Absolute Importance (RIa). Similar groups were defined for the trophic chain using the average linkage method. Feeding strategies were stenophagic in only the species Herichthys minckleyi and euryphagic in the other eight species. The main food categories found in the stomach contents of the fish community were insects, crustaceans, gastropods, plants and teleosts. Four functional groups were defined for the trophic chain, with no top consumer fish species. Despite this, the fish were observed to be regulators, mainly of invertebrates. The chain reaction in the control of food was thus greater from the top to the bottom.

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