scholarly journals Somatic energy content and histological analysis of the gonads in Antarctic fish from the Scotia Arc

2005 ◽  
Vol 69 (S2) ◽  
pp. 305-316 ◽  
Author(s):  
Fabián Alberto Vanella ◽  
Jorge Calvo ◽  
Elba Rosa Morriconi ◽  
Daniel Ramón Aureliano
Keyword(s):  
Histological Analysis ◽  
Energy Content ◽  
Antarctic Fish ◽  
Scotia Arc ◽  
Somatic Energy

Freshwater Migration as a Determinant Factor in the Somatic Cost of Reproduction of Two Anadromous Coregonines of James Bay

1990 ◽  
Vol 47 (2) ◽  
pp. 318-334 ◽  
Author(s):  
Yvan Lambert ◽  
Julian J. Dodson
Keyword(s):  
Energy Cost ◽  
Reproductive Effort ◽  
Energy Content ◽  
Cost Of Reproduction ◽  
Energy Gain ◽  
Lake Whitefish ◽  
James Bay ◽  
Energy Increase ◽  
Species Specific ◽  
Somatic Energy

We tested the hypothesis that the species-specific costs of migration differentially affect reproductive effort and somatic cost of reproduction in sympatric anadromous populations of cisco (Coregonus artedii) and lake whitefish (C. clupeaformis) of James Bay. Reproductive effort, which includes the energy cost of migration, is higher for cisco. Female cisco allocate more energy to reproduction than its total energy gain. The energy invested by lake whitefish in reproduction is approximately equal to its seasonal energy gain. Reproduction results in large differences in the energy content of gonads, viscera, and carcass between reproductive and nonreproductive fish of the same length. Neither cisco nor lake whitefish are able to spawn two years in succession. The somatic energy increase of reproductive female cisco is 121% lower than the somatic energy increase of nonreproductive females; similar comparisons are 89% (female) and 103% (male) for lake whitefish. The energy cost of migration is largely responsible for the higher somatic cost of reproduction observed for cisco. These different somatic costs of migration are related to resource accumulation prior to migration and to differences in the aerobic cost of swimming between the two species in combination with the difficulty of the freshwater migration.

Energy content of mesopelagic fish from Macquarie Island

2002 ◽  
Vol 14 (3) ◽  
pp. 225-230 ◽  
Author(s):  
MEGAN TIERNEY ◽  
MARK A. HINDELL ◽  
SIMON GOLDSWORTHY
Keyword(s):  
Water Content ◽  
Energy Content ◽  
Antarctic Fish ◽  
Dry Weight ◽  
Size Class ◽  
Trophic Levels ◽  
Mesopelagic Fish ◽  
Macquarie Island ◽  
Future Assessment ◽  
Calorific Content

The water and calorific content of fifteen species of mesopelagic sub-Antarctic fish from Macquarie Island were determined. Mean percent water content was 69–82%. Calorific content was highly variable between species, especially in the Myctophidae, where it ranged between 22.6–59.3 kJ·g−1 dry weight. The water and calorific content varied with size class within a species, with the smallest size classes generally having the lowest water content but highest calorific content. These values will be useful for future assessment of energetic transfer between trophic levels and energetic modelling of Southern Ocean ecosystems.

The role of environmental conditions in the seasonal synthesis and utilisation of biochemical energy reserves in the giant scallop, Placopecten magellanicus

1990 ◽  
Vol 68 (4) ◽  
pp. 750-756 ◽  
Author(s):  
R. J. Thompson ◽  
B. A. MacDonald
Keyword(s):  
Shallow Water ◽  
Spring Bloom ◽  
Energy Content ◽  
Somatic Tissue ◽  
Unit Weight ◽  
Energy Reserves ◽  
Lipid Levels ◽  
Placopecten Magellanicus ◽  
Somatic Energy

Throughout most of the year, carbohydrate and lipid levels in the somatic tissue of scallops from 31 m depth at Sunnyside, Trinity Bay, Newfoundland, were lower than corresponding levels in scallops from 10 m depth at the same location, resulting in a higher energy content per unit weight in the latter group. In the gonad, however, there was no difference between the groups in the concentrations of carbohydrate and lipid. The absolute quantities of these biochemical constituents in both gonad and somatic tissue were greater in scallops from shallow water, owing to their higher body weight. Thus, in the poorer conditions associated with deeper water at this site, scallops maintained carbohydrate and lipid pools in the gonad but did not accumulate somatic energy reserves to the same extent as did scallops from shallow water where conditions were more favourable. Individuals from 31 m were therefore less well buffered against environmental stress than those from 10 m. Biochemical energy reserves were deposited during and after the spring bloom, but not in the period after spawning. The loss of somatic carbohydrate during overwintering was greater in scallops from 31 m, and only in this group was there any utilisation of carbohydrate and lipid in winter.

Demonstrating Nutrient Cost Gradients: A Brooklyn Case Study

2014 ◽  
Vol 84 (5-6) ◽  
pp. 244-251 ◽  
Author(s):  
Robert J. Karp ◽  
Gary Wong ◽  
Marguerite Orsi
Keyword(s):  
Low Income ◽  
Energy Content ◽  
Food Selection ◽  
The United States ◽  
United States Department ◽  
Micronutrient Deficiencies ◽  
Caloric Density ◽  
Low Income Families ◽  
The Cost ◽  
The Impact

Abstract. Introduction: Foods dense in micronutrients are generally more expensive than those with higher energy content. These cost-differentials may put low-income families at risk of diminished micronutrient intake. Objectives: We sought to determine differences in the cost for iron, folate, and choline in foods available for purchase in a low-income community when assessed for energy content and serving size. Methods: Sixty-nine foods listed in the menu plans provided by the United States Department of Agriculture (USDA) for low-income families were considered, in 10 domains. The cost and micronutrient content for-energy and per-serving of these foods were determined for the three micronutrients. Exact Kruskal-Wallis tests were used for comparisons of energy costs; Spearman rho tests for comparisons of micronutrient content. Ninety families were interviewed in a pediatric clinic to assess the impact of food cost on food selection. Results: Significant differences between domains were shown for energy density with both cost-for-energy (p < 0.001) and cost-per-serving (p < 0.05) comparisons. All three micronutrient contents were significantly correlated with cost-for-energy (p < 0.01). Both iron and choline contents were significantly correlated with cost-per-serving (p < 0.05). Of the 90 families, 38 (42 %) worried about food costs; 40 (44 %) had chosen foods of high caloric density in response to that fear, and 29 of 40 families experiencing both worry and making such food selection. Conclusion: Adjustments to USDA meal plans using cost-for-energy analysis showed differentials for both energy and micronutrients. These differentials were reduced using cost-per-serving analysis, but were not eliminated. A substantial proportion of low-income families are vulnerable to micronutrient deficiencies.

Sign in / Sign up

Export Citation Format

Share Document