scholarly journals Diets of herring, mackerel, and blue whiting in the Norwegian Sea in relation to Calanus finmarchicus distribution and temperature conditions

2006 ◽  
Vol 63 (1) ◽  
pp. 117-127 ◽  
Author(s):  
Irina Prokopchuk ◽  
Evgeniy Sentyabov
Keyword(s):  
Stomach Content ◽  
Diet Composition ◽  
Pelagic Fish ◽  
Calanus Finmarchicus ◽  
Norwegian Sea ◽  
Main Prey ◽  
Blue Whiting ◽  
Important Prey ◽  
Hydrographic Conditions ◽  
Feeding Area

Abstract Diets of Norwegian spring-spawning herring, mackerel, and blue whiting in the Norwegian Sea are investigated in relation to the distribution of plankton and hydrographic conditions. Fish stomachs and zooplankton samples were collected during summer (June and July) cruises in 2001 and 2002. Calanus finmarchicus was the principal prey of mackerel, accounting for 53–98% of total stomach content by weight. The diet composition of herring varied depending on feeding area and availability of food under various environmental conditions. C. finmarchicus was important prey for herring only in July 2001 (about 77% by weight) in the central part of the sea and in June 2002 (about 82% by weight) near the Lofotens. In July 2002 appendicularians (Oikopleura spp.), amphipods (mainly Parathemisto abissorum), and euphausiids were important in the diet of herring, and at some stations cannibalism was observed. The main prey of blue whiting were amphipods (10–34% by weight), appendicularians (11–34%), and euphausiids (8–47%), as they usually feed deep in the water column, though C. finmarchicus was important, particularly in June 2002, when blue whiting were caught in the upper layers of the sea. Higher water temperatures indirectly affect pelagic fish through accelerated development of their prey and favourable conditions for migration farther north.

Trophic ecology of large pelagic fish in the Saint Peter and Saint Paul Archipelago, Brazil

2019 ◽  
Vol 70 (10) ◽  
pp. 1402 ◽  
Author(s):  
F. V. Albuquerque ◽  
A. F. Navia ◽  
T. Vaske ◽  
O. Crespo ◽  
F. H. V. Hazin
Keyword(s):  
Trophic Ecology ◽  
Feeding Habits ◽  
Saint Paul ◽  
Pelagic Fish ◽  
Trophic Niche ◽  
Trophic Relationships ◽  
Main Prey ◽  
Important Prey ◽  
Saint Peter ◽  
Prey Items

Trophic relationships of large pelagic predators can determine the structure and dynamics of oceanic food webs. The feeding habits and trophic ecology of five large pelagic fish (Acanthocybium solandri, Coryphaena hippurus, Elagatis bipinnulata, Thunnus albacares and Thunnus atlanticus) in the Saint Peter and Saint Paul Archipelago were evaluated to determine whether there is a trophic-niche overlap or resource partitioning among them. Eighty prey items found in 1528 stomachs were identified and grouped into Cephalopoda, Cnidaria, Crustacea, Gastropoda, Teleostei and Tunicata. Exocoetidae and Scombridae were the main prey in the diet of Acanthocybium solandri. In C. hippurus, Cheilopogon cyanopterus and Exocoetus volitans were the most important prey items, whereas C. cyanopterus was the main prey for T. albacares. Thunnus atlanticus consumed a great proportion of invertebrate species, with shrimps of Sergestidae family being particularly important. The gastropod Cavolinia sp. was the most important prey for E. bipinnulata. The five species had a high trophic specialisation and a high trophic level (>4.4), whereas most dietary overlaps were consistently low. The most important factor for diet dissimilarity was the consumption of Exocoetidade. All species were classified as top predators with varied diets, indicating their structural and functional importance in the food web of the Archipelago.

scholarly journals A new compilation of stomach content data for commercially-important pelagic fish species in the Northeast Atlantic

2014 ◽  
Vol 7 (1) ◽  
pp. 197-223 ◽  
Author(s):  
J. K. Pinnegar ◽  
N. Goñi ◽  
V. M. Trenkel ◽  
H. Arrizabalaga ◽  
W. Melle ◽  
...  
Keyword(s):  
Fish Species ◽  
North Atlantic ◽  
Stomach Content ◽  
Pelagic Fish ◽  
Bay Of Biscay ◽  
Predator Prey ◽  
Blue Whiting ◽  
The North ◽  
The North Atlantic ◽  
Prey Items

Abstract. There is increasing demand for information on predator-prey interactions in the ocean as a result of legislative commitments aimed at achieving sustainable exploitation. However, comprehensive datasets are lacking for many fish species and this has hampered development of multispecies fisheries models and the formulation of effective food-web indicators. This work describes a new compilation of stomach content data for five pelagic fish species (herring, blue whiting, mackerel, albacore and bluefin tuna) sampled across the northeast Atlantic and submitted to the PANGAEA open-access data portal (www.pangaea.de). We provide detailed descriptions of sample origin and of the corresponding database structures. We describe the main results in terms of diet composition and predator–prey relationships. The feeding preferences of small pelagic fish (herring, blue whiting, mackerel) were sampled over a very broad geographic area within the North Atlantic basin, from Greenland in the west, to the Lofoten Islands in the east and from the Bay of Biscay northwards to the Arctic. This analysis revealed significant differences in the prey items selected in different parts of the region at different times of year. Tunas (albacore and bluefin) were sampled in the Bay of Biscay and Celtic Sea. Dominant prey items for these species varied by location, year and season. This data compilation exercise represents one of the largest and most wide-ranging ever attempted for pelagic fish in the north Atlantic. The earliest data included in the database were collected in 1864, whereas the most recent were collected in 2012.Datasets are available at doi:10.1594/PANGAEA.820041 and doi:10.1594/PANGAEA.826992.

scholarly journals Diet of a Southweatern Most Population of Montagu’s Harrier (Ciercus pygargus) in the Palearctic

2020 ◽  
Vol 28 (2) ◽  
pp. 197-218
Author(s):  
Nuno Onofre
Keyword(s):  
Diet Composition ◽  
Birds Of Prey ◽  
Cereal Crops ◽  
Main Prey ◽  
Important Prey ◽  
Montagu’S Harrier ◽  
High Predation ◽  
Prey Remains ◽  
Cereal Fields ◽  
Montagu's Harrier

Data on Montagu’s Harrier biology was gathered in 1992 during a broader survey on birds of prey in the region of Castro Verde, during which pellets and prey remains were harvested in order to study their diet. Main land-use of the study area was extensive cereal crops with fallow fields. A total of 143 pellets collected in perches were analyzed and 1351 items were counted. Invertebrates were the main prey in number (97.2%) and biomass (32.9%). Birds and mammals were also important prey in terms of biomass (30.2 and 28%, respectively), despite its low numbers in relation to all identified prey (4.3 and 1.3%, respectively). Prey weighing less than 30 g were the most frequent (98.1%) with a corresponding biomass of around 62.1%. For prey weighing more than 100 g only Lagomorphs contributed to it, totaling 25% in terms of biomass, despite their remarkably low numbers (0.4% of total prey). This high predation on invertebrates while low on mammals agrees, with the known latitudinal trends of diet composition of the Montagu’s Harrier, and some other birds of prey, along the Palearctic. In this part of Iberia, where large orthopterans are particularly common in extensive cereal fields, strong presence of insects was found in the diet of Montagu’s Harrier populations. This feature seems to be related to the abundance of orthopterans in southern Europe.

scholarly journals Trophic ecology of Patagonian flounder Paralichthys patagonicus (Jordan, 1889) in the Argentine-Uruguayan Coastal Ecosystem

2021 ◽  
Vol 35 (1) ◽  
Author(s):  
Gonzalo H. Troccoli ◽  
Andrés C. Milessi ◽  
Noemí Marí ◽  
Daniel Figueroa ◽  
Agustín M. De Wysiecki
Keyword(s):  
Food Habits ◽  
Diet Composition ◽  
Trophic Ecology ◽  
Pelagic Fish ◽  
Coastal Ecosystem ◽  
Prey Category ◽  
Important Prey ◽  
Content Analyses ◽  
Size Groups ◽  
Wet Weight

Food habits and diet composition of Patagonian flounder Paralichthys patagonicus (Jordan, 1889) were studied on the basis of stomach content analyses from 828 specimens (512 females, 304 males, 12 unsexed) collected during 16 commercial cruises between February 2009 and April 2010 in the Argentine-Uruguayan Coastal Ecosystem (34° S-41° S). A total of 272 stomachs (32.9%) contained food (184 females and 84 males), among which 20 prey taxa were identified. The most important prey category was pelagic fish, primarily Argentine anchovy (Engraulis anchoita), followed by rough scad (Trachurus lathami). Evidence showed that females consumed a higher total wet weight of prey compared to males. Results also suggested a specialised diet over E. anchoita, across all sex and size groups. The estimated trophic level for the population of P. patagonicus was 4.16. This study suggests that P. patagonicus is a tertiary piscivorous consumer of the trophic food web in the region, and reveals changes in the prey consumption compared with previous studies.

scholarly journals Morphology and Stomach Content Analysis of Green Rough-backed Puffer Fish, Lagocephalus lunaris from Kuching, Sarawak

2016 ◽  
Vol 2 (2) ◽  
pp. 67-70
Author(s):  
Samsur Mohamad ◽  
Fadhilah Isa Isa
Keyword(s):  
Content Analysis ◽  
Stomach Content ◽  
Diet Composition ◽  
Morphological Characteristics ◽  
Stomach Content Analysis ◽  
Small Fish ◽  
Important Prey ◽  
Distribution Shape ◽  
Fin Rays ◽  
Puffer Fish

A total of 101 individuals of green rough-backed pufferfish, Lagocephalus lunaris were collected at two sampling sites and were assessed for their morphological characteristics and diet by stomach content analysis. The physical characteristics were observed and body weight (BW), total length (TL), standard length (SL) and number of fin rays were recorded. The results showed that the physical body measurement in all individuals were almost similar in their range of size (TL: 8.6 ± 0.3 cm; SL: 7.0 ± 0.2 cm; BW: 14.3 ± 1.5 g) and most individual had same distribution of spines at the dorsal part which extended to dorsal fin. The numbers of caudal, dorsal, pectoral and anal fin rays ranged from 5 to 12, 7 to 11, 9 to 12 and 7 to 17, respectively. Analysis of the diet composition showed that fish is carnivorous which prey on crabs, prawns, small fish and squids. Based on index of relative importance, crabs were identified as most important prey in Site 1 and Site 2, with value of (47.5, 55.6%), and followed by prawns (36.3, 38.2%), fish (5.6, 11.2%), squids (0.7, 2.9%) and bivalves (0.1, 1.7%). Our results suggest that L. lunaris had unique spines distribution shape which important for species identification and it consumed mainly on crustacean as diet composition. To our knowledge, this is the first attempt to describe morphological characteristics and stomach content of L. lunaris which inhabit in Sarawak waters.

scholarly journals Feeding of Atlantic salmon (Salmo salar L.) post-smolts in the Northeast Atlantic

2006 ◽  
Vol 63 (8) ◽  
pp. 1488-1500 ◽  
Author(s):  
Monika Haugland ◽  
Jens Christian Holst ◽  
Marianne Holm ◽  
Lars Petter Hansen
Keyword(s):  
Atlantic Salmon ◽  
Condition Factor ◽  
Pelagic Fish ◽  
Norwegian Sea ◽  
Northeast Atlantic ◽  
The North ◽  
Important Prey ◽  
The United Kingdom ◽  
Spawning Areas ◽  
High Condition

Abstract Stomach samples from 1384 Atlantic salmon, collected from 1991 to 2003 in the Northeast Atlantic, were analysed to fill the gap between studies on post-smolt diet in fjords and coastal areas of the Northeast Atlantic and studies on the diet of pre-adults and adults in the Norwegian Sea. The post-smolts fed largely on 0-group fish. Blue whiting was an important prey only in the slope current transporting the larvae from the spawning areas west of the United Kingdom into the North and Norwegian Seas. Sandeel and herring were important or present in the stomachs throughout most of the area studied. Unusually large quantities of 0-group herring in the Norwegian Sea in summer 2002 coincided with a high condition factor of post-smolts that year. The forage ratio of the post-smolts was positively related to the proportion of herring in the stomachs and the abundance of herring recruits. Despite these findings, the most productive period for Atlantic salmon on record, the 1970s, coincided with the collapse of the Norwegian spring-spawning herring, which raises the question as to whether herring is more important as a competitor than as a food source. Hyperiid amphipods were more important prey than krill, in contrast to the situation for other pelagic fish species.

scholarly journals Feeding Ecology of Short-Toed Snake-Eagle (Circaetus gallicus [Gmelin, 1788]) in the Montados of Iberian Peninsula

2020 ◽  
Vol 28 (2) ◽  
pp. 155-179
Author(s):  
Nuno Onofre ◽  
Luís Sampaio
Keyword(s):  
Relative Abundance ◽  
Diet Composition ◽  
Prey Species ◽  
Prey Selection ◽  
Prey Type ◽  
Generalist Predator ◽  
Important Prey ◽  
Psammodromus Algirus ◽  
Circaetus Gallicus ◽  
Water Snakes

The diet of Short-toed Snake-eagle (Circaetus gallicus) during the breeding season in an area dominated by cork and holm oak parkland forests (Montados) was analyzed in this study. As expected, results showed that snakes are the dominant prey in the diet of this eagle, comprising up to 92.5% of the identified items, if potential secondary prey species were excluded. The Montpellier Snake (Malpolon monspessulanus) was the most consumed one (42.2%), followed by the Ladder Snake (Zamenis scalaris) (28.0%), and the water snakes (Natrix spp.) (14.2%). According to the same criteria, lizards (mainly Psammodromus algirus) and mammals represent between 4.8 and 2.2%, respectively. Other animals such as pond turtle and amphibians are irregular prey (<1%), and no bird remains were found at all. Short-toed Snake-eagle is usually referred as a stenophagic predator where snakes are by far its most important prey type, and where within this taxonomic group it behaves as a generalist predator. In this study this premise was then tested comparing the relative abundance of the snake species with their proportion in the diet composition of the eagle in order to know whether or not prey selection exists with regard to the species of snakes in this region. Results point to a quite plausible "preference" for the Ladder Snake and an "avoidance" for the smooth snakes group (Macroprotodon brevis/Coronella girondica), and possibly for the Horseshoe Whip (Hemorrhois hippocrepis). The avoidance to the Horseshoe Whip must be indirect and habitat related, while in relation to the two smooth snakes it may be due in large extend to its small size, in particular.

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