scholarly journals Effect of food availability on the growth and thermal physiology of juvenile Dungeness crabs (Metacarcinus magister)

2015 ◽  
Vol 3 (1) ◽  
pp. cov013 ◽  
Author(s):  
Katherine M. McLean ◽  
Anne E. Todgham
Keyword(s):  
Food Availability ◽  
Thermal Physiology ◽  
Effect Of Food ◽  
Dungeness Crabs

Daily changes in food availability, but not long-term unpredictability, determine daily torpor-bout occurrences and frequency in stripe-faced dunnarts (Sminthopsis macroura)

2015 ◽  
Vol 63 (1) ◽  
pp. 12 ◽  
Author(s):  
Alexandra M. Leslie ◽  
Mathew Stewart ◽  
Elizabeth Price ◽  
Adam J. Munn
Keyword(s):  
Food Availability ◽  
Control Period ◽  
Daily Torpor ◽  
Torpor Bout ◽  
Effect Of Food ◽  
Rapid Adjustment ◽  
Sminthopsis Macroura ◽  
Ad Libitum ◽  
Ad Libitum Intake ◽  
Ad Libitum Feeding

Daily torpor, a short-term reduction in body temperature and metabolism, is an energy-saving strategy that has been interpreted as an adaptation to unpredictable resource availability. However, the effect of food-supply variability on torpor, separately from consistent food restriction, remains largely unexamined. In this study, we investigated the effect of unpredictable food availability on torpor in stripe-faced dunnarts (Sminthopsis macroura). After a control period of ad libitum feeding, dunnarts were offered 65% of their average daily ad libitum intake over 31 days, either as a constant restriction (i.e. as equal amount of food offered each day) or as an unpredictable schedule of feed offered, varied daily as 0%, 30%, 60%, 100% or 130% of ad libitum. Both feeding groups had increased torpor-bout occurrences (as a proportion of all dunnarts on a given day) and torpor-bout frequency (average number of bouts each day) when on a restricted diet compared with ad libitum feeding, but torpor frequency did not differ between the consistently restricted and unpredictably restricted groups. Most importantly, torpor occurrence and daily bout frequency by the unpredictably restricted group appeared to change in direct association with the amount of food offered on each day; torpor frequency was higher on days of low food availability. Our data do not support the interpretation that torpor is a response to unpredictable food availability per se, but rather that torpor allowed a rapid adjustment of energy expenditure to manage daily fluctuations in food availability.

Diet shifts in 0+ nase, Chondrostoma nasus: Size-specific differences and the effect of food availability

River Systems ◽  
2001 ◽  
Vol 12 (2-4) ◽  
pp. 425-440 ◽  
Author(s):  
W. Reckendorfer ◽  
H. Keckeis ◽  
V. Tutu ◽  
G. Winkler ◽  
H. Zornig ◽  
...  
Keyword(s):  
Food Availability ◽  
Chondrostoma Nasus ◽  
Effect Of Food ◽  
Diet Shifts

Effect of food availability on the acute toxicity of four chemicals tomysidopsis bahia(mysidacea) in static exposures

1989 ◽  
Vol 8 (4) ◽  
pp. 333-338 ◽  
Author(s):  
Geraldine M. Cripe ◽  
Anne Ingley-guezou ◽  
Larry R. Goodman ◽  
Jerrold Forester
Keyword(s):  
Acute Toxicity ◽  
Food Availability ◽  
Effect Of Food

Effect of food availability on reproduction and brood size in a freshwater brooding bivalve

2003 ◽  
Vol 81 (7) ◽  
pp. 1168-1173 ◽  
Author(s):  
Mark A Beekey ◽  
Ronald H Karlson
Keyword(s):  
Food Availability ◽  
Brood Size ◽  
Reproductive Strategies ◽  
Common Garden ◽  
Relative Importance ◽  
Common Garden Experiment ◽  
Freshwater Bivalve ◽  
Physical Constraints ◽  
Effect Of Food ◽  
Energetic Constraints

Brood size is often constrained by the amount of energy available to produce offspring. Yet, energetic constraints may not be as important if the physical capacity to brood offspring is limited. Investigating the relative importance of energetic and physical constraints on brood size is necessary to understand how reproductive strategies are molded by natural selection. We investigated how food availability affects brood size in Sphaerium striatinum, a freshwater bivalve. We reared juveniles to adulthood under three food levels in a common garden experiment. The number of reproductive attempts, brood size, and stage of offspring development were measured. Clams reared with the most food reproduced more often, produced more offspring per reproductive attempt, and contained larger broods than clams reared with less food. These data support the notion that food availability is an important factor in the production of offspring and overall brood size. However, the number of offspring surviving to later stages of development was not different among treatments. In fact, clams reared with the most food lost proportionately more offspring than clams reared with less food. We conclude that physical constraints are more important in determining overall brood size than energetic constraints in S. striatinum.

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