scholarly journals Seasonal and inter-annual oceanographic changes induce diet switching in a piscivorous seabird

2009 ◽  
Vol 393 ◽  
pp. 273-284 ◽  
Author(s):  
M Ito ◽  
H Minami ◽  
Y Tanaka ◽  
Y Watanuki
Keyword(s):  
Diet Switching

Diet switching in a generalist mammalian folivore: fundamental to maximising intake

Oecologia ◽  
2005 ◽  
Vol 147 (4) ◽  
pp. 650-657 ◽  
Author(s):  
Natasha L Wiggins ◽  
Clare McArthur ◽  
Noel W Davies
Keyword(s):  
Diet Switching

Mucus: a new tissue fraction for rapid determination of fish diet switching using stable isotope analysis

2009 ◽  
Vol 66 (1) ◽  
pp. 1-5 ◽  
Author(s):  
M. Robbins Church ◽  
Joseph L. Ebersole ◽  
Kirk M. Rensmeyer ◽  
Ryan B. Couture ◽  
Frederic T. Barrows ◽  
...  
Keyword(s):  
Stable Isotope ◽  
Stable Isotope Analysis ◽  
Half Life ◽  
Rapid Determination ◽  
Juvenile Fish ◽  
Isotope Analysis ◽  
Fish Diet ◽  
Additional Advantage ◽  
Diet Switching ◽  
Fish Mucus

Stable isotope analysis of diet switching by fishes often is hampered by slow turnover rates of the tissues analyzed (usually muscle or fins). We examined epidermal mucus as a potentially faster turnover “tissue” that might provide a more rapid assessment of diet switching. In a controlled hatchery experiment, we switched the diet of juvenile steelhead (sea-run rainbow trout, Oncorhynchus mykiss ) from a plant-based feed with low δ13C and δ15N to a fish-meal-based diet with higher delta values. We found mucus to provide a significantly more rapid response to diet switching (half-life = 36 days for δ15N, 30 days for δ13C) than muscle tissue (half-life = 94 days for δ15N, 136 days for δ13C), even for growing juvenile fish. Mucus may provide a rapid turnover “tissue” for analysis of diet (or habitat) switching by fish. It has the additional advantage that it may be sampled nonlethally in some fishes, thereby avoiding problems in studying threatened or endangered species. This is the first report of the use of fish mucus in stable isotope analyses of fish tissues.

Diet switching of seed-eating birds wintering in grazed habitats of the central Monte Desert, Argentina

The Condor ◽  
2017 ◽  
Vol 119 (4) ◽  
pp. 673-682 ◽  
Author(s):  
Luis Marone ◽  
Matías Olmedo ◽  
Daniela Y. Valdés ◽  
Agustín Zarco ◽  
Javier Lopez de Casenave ◽  
...  
Keyword(s):  
Monte Desert ◽  
Diet Switching ◽  
Seed Eating

scholarly journals Reproductive phenology of Hong Kong shrubland

1993 ◽  
Vol 9 (4) ◽  
pp. 501-510 ◽  
Author(s):  
Richard T. Corlett
Keyword(s):  
Hong Kong ◽  
Plant Species ◽  
Reproductive Phenology ◽  
Community Patterns ◽  
Diet Switching ◽  
Northern Edge ◽  
The Tropics

ABSTRACTHong Kong is on the northern edge of the tropics and near the boundary of the Paleotropical and Holarctic floral kingdoms. The phenological states of 105 plant species in secondary shrubland were recorded weekly for three years. Community patterns of reproductive phenology are highly seasonal and vary little between years. There is a flowering maximum in May and a fruiting maximum in December/January. The winter fruiting peak coincides with diet switching by resident omnivorous birds and the arrival of partially frugivorous migrants from the Eastern Palearctic. However, wind-dispersed species also have a fruiting maximum at the same time, suggesting that fruiting in winter has other advantages.

Fitness benefits of size-dependent diet switching in a marine herbivore

2012 ◽  
Vol 159 (5) ◽  
pp. 1001-1010 ◽  
Author(s):  
Jane E. Williamson ◽  
Peter D. Steinberg
Keyword(s):  
Size Dependent ◽  
Diet Switching ◽  
Marine Herbivore ◽  
Fitness Benefits

Gastroliths in Yanornis: an indication of the earliest radical diet-switching and gizzard plasticity in the lineage leading to living birds?

2004 ◽  
Vol 91 (12) ◽  
pp. 571-574 ◽  
Author(s):  
Zhonghe Zhou ◽  
Julia Clarke ◽  
Fucheng Zhang ◽  
Oliver Wings
Keyword(s):  
Diet Switching

The Protective Role of Dietary Calcium Against Cadmium Uptake and Toxicity in Freshwater Fish: an Important Role for the Stomach

2006 ◽  
Vol 3 (6) ◽  
pp. 389 ◽  
Author(s):  
Chris M. Wood ◽  
Natasha M. Franklin ◽  
Som Niyogi
Keyword(s):  
Freshwater Fish ◽  
Calcium Uptake ◽  
Dietary Calcium ◽  
Freshwater Ecosystems ◽  
Cadmium Uptake ◽  
Diet Switching ◽  
Uptake Pathway ◽  
Waterborne Exposure ◽  
In The Wild ◽  
Waterborne Cadmium

Environmental Context. Contamination of freshwater ecosystems by cadmium is of increasing concern with accumulation and toxicity in aquatic animals occurring through both waterborne and dietary routes. Increases in water calcium (‘hardness’) levels protect against waterborne uptake. Physiological research on freshwater fish has demonstrated that this occurs because cadmium moves through the calcium uptake pathway at the gills. Surprisingly, elevated dietary calcium also protects against waterborne exposure by down-regulating the calcium uptake pathway at the gills, and against dietary exposure by reducing cadmium uptake through the gastrointestinal tract. In both cases, the stomach is the critical site of action. Abstract. Waterborne cadmium causes toxicity in freshwater fish by inducing hypocalcaemia. Research on the rainbow trout (Oncorhynchus mykiss), a sensitive model species, has demonstrated that this occurs because Cd2+ ions compete with waterborne Ca2+ ions for the active branchial uptake pathway which normally ensures internal homeostasis of calcium levels. Therefore, increases in waterborne calcium concentrations (‘hardness’) protect against waterborne cadmium uptake and toxicity in both acute and chronic exposures. Increases in dietary calcium concentration also protect against waterborne exposure, because elevated gastrointestinal calcium uptake down-regulates the Ca2+ uptake pathway at the gills, thereby simultaneously reducing Cd2+ entry. Furthermore, dietary calcium also protects against dietborne cadmium exposure, although the physiological mechanisms appear to differ from those at the gills. Surprisingly, the principal site of this inhibitory action of dietary calcium on gastrointestinal cadmium uptake appears to be the stomach, which is also the major site of gastrointestinal calcium uptake, rather than the intestine as in mammals. These results underline the importance of considering not only water chemistry but also dietary chemistry in the environmental regulation of cadmium, and suggest that fish in the wild under chronic cadmium stress would benefit by switching to a more calcium-rich diet. While diet switching has been seen in the wild in fish under metal stress, its etiology remains unknown; to date, laboratory experiments have not been able to show that voluntary diet-switching of an adaptive nature actually occurs.

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