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1.
Three-spined stickleback consumed prey of one size until the stomach was full whereafter similar-sized prey were rejected, but smaller prey were consumed. This evidence leads to the prediction of a shift in prey size preference as a result of the constraint imposed by remaining stomach capacity. 相似文献
2.
Agata Joanna Krawczyk Michał Bogdziewicz Katarzyna Majkowska Adam Glazaczow 《Mammal Review》2016,46(2):106-113
- The Eurasian otter Lutra lutra is a top predator that feeds mostly on fish. Yet, studies show the high plasticity of otter foraging behaviour and the varying importance of alternative food types in the species' diet.
- The aims of this study were, firstly, to demonstrate by meta‐analysis how the diet composition of otters varies depending on the habitat occupied, in terms of the types of land use, waterbody, and bank vegetation. Secondly, we tested whether the choice of method of presenting prey percentages in the diet of otters influenced the conclusions of the meta‐analysis.
- The percentage of fish in the diet was greater for otters occupying standing water than for those occupying flowing water; was higher for otters in waterbodies overgrown by reed vegetation; and varied depending on the type of surrounding land use. However, the results of the meta‐analysis varied depending on which of the two most common methods of diet analysis were used: percentage biomass or relative frequency of occurrence (RFO).
- We showed that the plasticity of otter feeding behaviour might be explained by the various habitats occupied by otters. Habitat differences reflected in otters' diets might have importance for the maintenance and conservation of local populations of this species.
- The high diversity of methods used by researchers to report the results of dietary studies precludes full comparisons and synthesis. This demonstrates the importance of unification of reporting. Moreover, the conclusions reached by the authors of any particular study might be highly dependent on the method they applied. Thus, care should be taken when comparing ecological studies based on different methods.
3.
选取象山港黑鲷个体为研究对象,以18S rDNA为靶标,利用Illumina Miseq高通量测序方法研究黑鲷饵料生物组成特征,分析不同龄组黑鲷的食性异同。通过序列比对,共在黑鲷胃含物中鉴定出41个属中的62种饵料生物,分属9个门,其中节肢动物门(Arthropoda)、绿藻门(Chlorophyta)和软体动物门(Mollusca)是黑鲷饵料生物的优势组成门类。从饵料生物相对丰度和出现频率上分析,石莼(Ulva lactuca)、熊本牡蛎(Crassostrea sikamea)、胸刺水蚤(Centropages hamatus)、日本蟳(Charybdis japonica)、毛蚶(Scapharca subcrenata)和褐菖鲉(Sebastiscus marmoratus)是黑鲷的优势饵料物种,所占饵料生物总相对丰度的比重达60.90%。相似性分析检验(ANOSIM)结果显示:1至4龄黑鲷个体的饵料生物组成不存在显著性差异。与传统食性分析方法相比,高通量测序法在黑鲷饵料生物检测灵敏性上显现了较为明显的优势,保障黑鲷等重要物种的种群稳定对于该海域具有重要的生态和经济意义。 相似文献
4.
The feeding ecology of the small‐bodied benthic naked goby Gobiosoma bosc, a western Atlantic species that occurs in estuaries and other inshore habitats from Connecticut to Texas U.S.A., was investigated in a total of four estuaries spanning South Carolina, North Carolina, Maryland and New Jersey. Gut content analysis of 391 individuals revealed that G. bosc is a benthic microcarnivore that feeds primarily on polychaetes, gammarid amphipods and harpacticoid copepods. Diet composition varied with body size, tidal creek within an estuary and geographic region. Analyses of gut fullness suggest that G. bosc is a daytime visual predator and that nest and egg guarding during the reproductive season reduce foraging activity in mature males. Additionally, G. bosc infected with adult digenean parasites of the gut foraged more intensely than uninfected individuals, a relationship that was strongest for reproductively mature males. Regionally, significant variation in dietary breadth was documented and may reflect a foraging response to a decrease in prey diversity moving from estuaries of higher salinity and lower latitude to estuaries of lower salinity and higher latitude. These results contribute to an understanding of the life history of G. bosc and the role played by this common species in estuarine food webs. 相似文献
5.
洗胃法在鳄蜥食性研究中的应用 总被引:1,自引:0,他引:1
为了研究洗胃法是否适用于鳄蜥(Shinisaurus crocodilurus)的食性研究,2006年8~9月我们在广东罗坑省级自然保护区,通过投喂食物,然后再冲洗的方法来检验洗胃法的冲洗效果。结果显示洗胃法对成体和亚成体鳄蜥的总洗出率均高于99.30%,食物个体数的洗出率均高于90.83%,投喂的12种食物都能被洗出。观察发现洗胃之后,对鳄蜥的正常生活没有影响。鳄蜥吃进的实验食物中,未洗出的食物大小与鳄蜥的体长、头宽、体重不相关;食物的洗出效率与鳄蜥的体长、头宽、体重不相关。成体、亚成体洗出和未洗出的食物大小均存在显著差异。未被洗出的食物个体在12种食物中不是随机分布的,体积大的食物比体积小的食物容易被洗出。研究表明,洗胃法适用于鳄蜥的食性研究,并且效果较好。 相似文献
6.
Species composition and food habits of four istiophorid billfishes were investigated and compared in three different tropical areas of the eastern North Pacific Ocean by longline operations from September to November 2004. Sailfish Istiophorus platypterus, shortbill spearfish Tetrapturus angustirostris and blue marlin Makaira nigricans had specific habitat preferences and mainly occurred in the near‐continent area (13–16° N; 103–107° W), the open‐ocean area (16–18° N; 118–134° W) and the near‐equator area (5° N; 104–120° W). Small (<140 cm in lower jaw–fork length) striped marlin Kajikia audax mainly occurred in the near‐continent area; however, large (≥140 cm) individuals occurred throughout all three areas. Prey compositions of large K. audax in the three areas were different from one other reflecting the prey availability in each area. In the open‐ocean area, molid fishes were dominant in mass for both large K. audax (49%) and T. angustirostris (73%), and large K. audax also fed on ostraciid (33%) and scombrid fishes (15%). In the near‐continent area, tetraodontid fishes were dominant for large and small I. platypterus (54, 57%), and both large and small K. audax also fed on tetraodontid fishes (3, 12%). Large K. audax in this area fed mainly on scombrid fishes (86%). These results indicate that large K. audax show overlaps but little segregations of its prey with other billfishes. In the near‐equator area, stomach contents of large K. audax and M. nigricans were few and billfish prey items were thought to be scarce. 相似文献
7.
中国花鲈(Lateolabrax maculatus)是长江口重要的经济鱼类之一。根据2010年7月至10月在长江口崇明东滩团结沙和东旺沙水域采集到的胃含物样品,对中国花鲈的摄食习性进行了研究。结果表明,从中国花鲈胃含物中共鉴定出6类27种饵料生物,其多样性指数H’值为2.484,均匀度指数J’为0.7535,优势指数D为0.1262。采用百分比相对重要性指数(IRI%)和综合指标优势指数(Ip)分析的结果较一致,鱼类是长江口中国花鲈夏季主要食物,其百分比相对重要性指数(IRI%)和综合指标优势指数(Ip)分别为82.63%和94.48,鮻(Liza haematocheila)为优势饵料生物(IRI%=41.89,Ip=53.20)。团结沙和东旺沙中国花鲈食性差异较大,主成分分析(PCA)表明鲚属(Coilia spp.)、舌虾虎鱼(Glossogobius giuris)、脊尾白虾(Exopalaemoncarinicauda)和雷伊著名团水虱(Gnorimosphaeroma rayi)是造成这种差异的主要饵料生物种类。 相似文献
8.
Lake Agmon was created in the Hula Valley in Israel, in the northern part of the dried-up Hula Lake site, in summer, 1994. Samples of fish at ten stations were taken by electroshocker once a month, from January to December, 1996. The fish species whose food composition in the gut was examined in this study were: Tilapia zillii, Gambusia affinis, Clarias gariepinus, Cyprinus carpio, Pseudophoxinus kervillei, Acanthobrama lissneri, Hemigrammocapoeta nana and Oreochromis aureus. Food components were determined qualitatively and quantitatively. Assessment of the organism biomass in the gut contents was based on available data of phytoplankton and zooplankton. The food of G. affinis changed during the year, consisting high level of algae in winter and spring, and insects and crustaceans in summer. In T. zillii, a high percentage of algae were found in winter, and a high percentage of plants in summer. The food of H. nana consisted mainly of phytoplankton, but included high plants during most months; P. kervillei ingested mainly insects and crustaceans, with a high percentage of Daphnia spp.; and the diet of C. gariepinus comprised fish and invertebrates species, which varied with the seasons. C. carpio ate mainly invertebrates; O. aureus are vegetarian, and A. lissneri fed on both animals and plants. This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
9.
The diet of Bubo capensis mackinderi Sharpe in the alpine zone of Mt. Kenya was studied by analysing pellets collected from nesting and roosting sites in four different valleys. Overall, mammals comprised 97.4% of prey individuals and 98.9% of the ingested biomass. Rodents, mainly groove‐toothed rats, were the owl's staple food in all four valleys, but rock hyrax, insectivores and birds were also consumed. Proportions of rock hyrax, rodents and insectivores did not differ between the valleys. Total dietary composition in the different valleys showed a high degree of overlap in proportions of main prey types averaging 93.2% in percentage of occurrence and 85.0% in percentage of biomass. 相似文献
10.
Damon P. Gannon Andrew J. Ready James E. Craddock James G. Mead 《Marine Mammal Science》1997,13(3):405-418
Ten prey taxa were recorded from the stomach contents of eight long-finned pilot whales ( Globicepbala melas ) independently stranded along the U.S. mid-Atlantic coast. Relative importance of prey species was determined by methods that incorporate prey frequencies of occurrence, proportions of numerical abundance, and proportions of reconstructed mass. Separate analyses of trace (free, durable body parts representing well-digested prey items) and non-trace (relatively intact prey specimens) food material were conducted in order to address biases caused by differential rates of digestion and passage through the gastrointestinal tract. Different measures of prey importance yielded varying results, but the long-finned squid ( Loligo pealei ) was the most important prey species regardless of how prey importance was defined. Fishes were relatively unimportant in the diet. Our results indicate that the diets of western North Atlantic long-finned pilot whales differ substantially from what has been previously reported in the literature and that results from food-habits studies that utilize different techniques may not be comparable. 相似文献
11.
In this study, the feeding behaviour of the non‐native invasive predatory fishes largemouth bass Micropterus salmoides and bluegill Lepomis macrochirus was studied in the Ezura River, a northern tributary of Lake Biwa, Japan. Prey composition was estimated based on visual examination of stomach contents and faecal DNA analysis to determine feeding habits of these predatory fishes. Stomach content analysis showed that native fishes (e.g. ayu Plecoglossus altivelis and gobies Rhinogobius spp.) and shrimps (e.g. Palaemon paucidens) were the major prey items for M. salmoides, while snails, larval Chironomidae and submerged macrophytes were the dominant prey items of L. macrochirus. Micropterus salmoides tended to select larger fish in the case of crucian carp Carassius spp., but smaller fishes in the case of P. altivelis and Rhinogobius spp. Faecal DNA analyses revealed prey compositions similar to those identified in predator stomach contents, and identified additional prey species not detected in stomach content inspection. This study demonstrated that both stomach content inspection and DNA‐based analysis bear several inherent shortcomings and advantages. The former method is straightforward, although identification of species can be inaccurate or impossible, whereas the latter method allows for accurate species identification, but cannot distinguish prey size or stage. Hence, integration of morphology‐based and DNA‐based methods can provide more reliable estimates of foraging habits of predatory fishes. 相似文献
12.
I. Byrkjedal O. V. Karamushko G. Langhelle A. Lynghammar 《Journal of fish biology》2015,86(1):360-364
During scientific surveys on the continental slopes north‐west of Spitsbergen and off north‐east Greenland (c. 600 and 1000 m depths), two female Arctic skates Amblyraja hyperborea were caught while swallowing extraordinary large individuals of glacial eelpout Lycodes frigidus. The total length (LT) of the prey constituted 50 and 80% of the LT of the skates, which reveal that A. hyperborea are capable predators of fishes of surprisingly large relative size. 相似文献
13.
This study examined diet, prey quality and growth for a generalist fish predator, grey snapper Lutjanus griseus, at five sites across an estuarine gradient in the Loxahatchee River estuary, Florida, U.S.A. Lutjanus griseus diets shifted from dominance by low quality, intertidal crabs upstream to an increased reliance on higher quality shrimp, fishes and benthic crabs downstream. Frequency of L. griseus with empty stomachs was higher at downstream sites. Lutjanus griseus growth rates did not vary among sites. Results indicate that L. griseus may be able to compensate for lower quality prey upstream by consuming more, and thus individuals are able to maintain similar levels of energy balance and growth rates across the estuarine gradient. Elucidating mechanisms, such as compensatory feeding, that enable generalist species to remain successful across habitat conditions are critical to understanding their organismal ecology and may facilitate predictions about the response of generalists to landscape alteration. 相似文献
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15.
Arariky S. Shikongo;Margit R. Wilhelm; 《Journal of fish biology》2024,105(6):1703-1714
In this study, we described and compared the diet, monthly feeding intensity, and condition of west coast steenbras (Lithognathus aureti) and silver kob (Argyrosomus inodorus) caught at a unique habitat in the northern Benguela. Stomach contents of 179 west coast steenbras and 114 silver kob caught from October 2020 to September 2022 were investigated. The peak in feeding intensity of west coast steenbras appeared to be opportunistic during winter and summer periods depending on food availability. The fish condition, however, peaked at the beginning (October) and at the end (April) of the austral summer spawning period, with the hepatosomatic index (HSI) at 1.5% and the condition factor (CF) at 0.022%. Seven prey taxa were found in the diet of west coast steenbras (bivalves, bony fishes, other mollusks, algae, crustaceans, cnidaria, and polychaetas) and six taxa in the diet of silver kob (bivalves, crustaceans, bony fishes, algae, starfish, and zooplankton), indicating generalist feeding behavior in both the species. The bivalves were the most important prey items in the diet of west coast steenbras (95.9% index of relative importance [IRI]). The most important prey items in the diet of silver kob were crustaceans (83.1% IRI) and bony fishes (16.0% IRI). Crustaceans were most important in the diet of small-to-medium-sized silver kob, whereas bony fishes were most important in the diet of larger silver kob (>75 cm), with significant differences of IRI% by size class. Schoener's index of niche overlap indicated a relatively low overall niche overlap (0.11) between west coast steenbras and silver kob. This allows them to coexist as their feeding habits allow them to occupy unique niches in the coastal reef and sandy habitat and reduce competition for resources. 相似文献
16.
Changes in the foraging behaviour due to variation in the body size of the three-spined stickleback Gasterosteus aculeatus were investigated. All sizes of fish had a high probability of attacking prey whenever encountered. The probability of eating the prey increased with the size of the fish, as the larger fish had larger jaws and a greater stomach capacity. Therefore, as fish increased in size there was an increase in the probability of successful prey capture. The level of satiation did not have an effect on the prey handling time, which is contrary to other studies and is probably a result of the large prey sizes. The physical size of the prey meant that the handling times were long regardless of the motivational level of the fish. The larger fish took in more energy and at a faster rate, although the time to reach satiation was similar for all fish sizes. The advantage that large fish appear to have in successfully gaining large prey is negated by their greater metabolic requirement. The changes in feeding performance induced by small increases in body size could have important consequences for intraspecific competition, habitat Use and risk of predation. 相似文献
17.
Spatial and Temporal Variability in the Diet of Anadromous Arctic Charr, Salvelinus Alpinus, In Northern Labrador 总被引:2,自引:0,他引:2
Spatial and temporal variation in the diet of anadromous Arctic charr, Salvelinus alpinus, was determined from over 2500 prey-containing stomachs collected from three stock complex areas in northern Labrador. Based on the percent wet mass, sand lance, Ammodytes spp., capelin, Mallotus villosus, and sculpins, Triglops spp. and Myoxocephalus spp., were the most important components of the diet in the Voisey stock complex, with capelin, sand lance, and hyperiid amphipods, Parathemisto spp., dominating in the Nain region. In contrast, hyperiid amphipods and sculpins were the main prey items in the more northern Hebron–Saglek complex indicating that diet differs among stocks, and at times over limited spatial scales. The relative importance of prey varied with size of predator. Mean weight of charr has declined over time (p < 0.01), and for one stock complex, is highly correlated with the average quantity of capelin found in the stomachs (r = 0.66, p < 0.001). Dietary shifts observed in anadromous charr in some areas of northern Labrador could be associated, in part, with changes in the distribution of capelin in the northwest Atlantic Ocean, possibly as a result of anomalous ocean climate conditions. 相似文献
18.
George A. Antonelis Jr. Mark S. Lowry Douglas P. DeMaster Clifford H. Fiscus 《Marine Mammal Science》1987,3(4):308-322
Stomach lavaging was used to study the feeding habits of northern elephant seals ( Mirounga angustirostris ) found on San Miguel Island, California, during the spring of 1984. Fifty-nine elephant seals were chemically immobilized with an intramuscular injection of ketamine hydrochloride. Once immobilized, an animal's stomach was intubated, filled with 3–4 liters of water to create a slurry of the undigested food items, and evacuated into a collection device. The stomachs of 57 (96.6%) of the animals lavaged contained identifiable parts of prey. Twenty-nine different food items were identified, 12 of which have not been previously reported as prey of the northern elephant seal: two teleost fish, Coryphaenoides acrolepis (Pacific rattail) and another unidentified macrourid; two crustaceans, Pasiphaea pacifica (glass shrimp) and Euphausia sp.; six squid, Abraliopsis felis, Gonatus berryi, Histioteuthis dofleini, Cranchia scabra, Taonius pavo, and Galiteuthis sp. and two octopi, Octopus dofleini and Octopus rubescens. 相似文献
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20.
Juvenile mugilid fishes, Liza falcipinnis, L. dumerilii, Mugil bananensis and M. curema , which enter the Elmina Lagoon in the Cape Coast District of Ghana, have a similar diet comprising mainly bacteria, diatoms, blue-green/green algae, protozoans, detritus and particulate organic matter. No seasonal changes in the diet and feeding activity were observed. The relative gut length (intestine to standard length ratio) and diet showed no significant changes with size of fish in all the species. All four species were diurnal feeders, but their peak feeding times differed. Interspecific competition for food was possibly limited by species preferences for substrate particles of particular size range and differences in feeding chronology. 相似文献