Translator Disclaimer
6 December 2011 A generalized model for estimating the energy density of invertebrates
Daniel A James, Isak J Csargo, Aaron Von Eschen, Megan D Thul, James M Baker, Cari-Ann Hayer, Jessica Howell, Jacob Krause, Alex Letvin
Author Affiliations +
Abstract

Invertebrate energy density (ED) values are traditionally measured using bomb calorimetry. However, many researchers rely on a few published literature sources to obtain ED values because of time and sampling constraints on measuring ED with bomb calorimetry. Literature values often do not account for spatial or temporal variability associated with invertebrate ED. Thus, these values can be unreliable for use in models and other ecological applications. We evaluated the generality of the relationship between invertebrate ED and proportion of dry-to-wet mass (pDM). We then developed and tested a regression model to predict ED from pDM based on a taxonomically, spatially, and temporally diverse sample of invertebrates representing 28 orders in aquatic (freshwater, estuarine, and marine) and terrestrial (temperate and arid) habitats from 4 continents and 2 oceans. Samples included invertebrates collected in all seasons over the last 19 y. Evaluation of these data revealed a significant relationship between ED and pDM (r2  =  0.96, p < 0.0001), where ED (as J/g wet mass) was estimated from pDM as ED  =  22,960pDM − 174.2. Model evaluation showed that nearly all (98.8%) of the variability between observed and predicted values for invertebrate ED could be attributed to residual error in the model. Regression of observed on predicted values revealed that the 97.5% joint confidence region included the intercept of 0 (−103.0 ± 707.9) and slope of 1 (1.01 ± 0.12). Use of this model requires that only dry and wet mass measurements be obtained, resulting in significant time, sample size, and cost savings compared to traditional bomb calorimetry approaches. This model should prove useful for a wide range of ecological studies because it is unaffected by taxonomic, seasonal, or spatial variability.

Society for Freshwater Science
Daniel A James, Isak J Csargo, Aaron Von Eschen, Megan D Thul, James M Baker, Cari-Ann Hayer, Jessica Howell, Jacob Krause, and Alex Letvin "A generalized model for estimating the energy density of invertebrates," Freshwater Science 31(1), 69-77, (6 December 2011). https://doi.org/10.1899/11-057.1
Received: 2 May 2011; Accepted: 1 October 2011; Published: 6 December 2011
JOURNAL ARTICLE
9 PAGES

This article is only available to subscribers.
It is not available for individual sale.
+ SAVE TO MY LIBRARY

SHARE
ARTICLE IMPACT
RIGHTS & PERMISSIONS
Get copyright permission
Back to Top