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Harrison JF, Biewener A, Bernhardt JR, Burger JR, Brown JH, Coto ZN, Duell ME, Lynch M, Moffett ER, Norin T, Pettersen AK, Smith FA, Somjee U, Traniello JFA, Williams TM. White Paper: An Integrated Perspective on the Causes of Hypometric Metabolic Scaling in Animals. Integr Comp Biol 2022; 62:icac136. [PMID: 35933126 PMCID: PMC9724154 DOI: 10.1093/icb/icac136] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2022] [Revised: 04/16/2022] [Accepted: 05/19/2022] [Indexed: 11/15/2022] Open
Abstract
Larger animals studied during ontogeny, across populations, or across species, usually have lower mass-specific metabolic rates than smaller animals (hypometric scaling). This pattern is usually observed regardless of physiological state (e.g. basal, resting, field, maximally-active). The scaling of metabolism is usually highly correlated with the scaling of many life history traits, behaviors, physiological variables, and cellular/molecular properties, making determination of the causation of this pattern challenging. For across-species comparisons of resting and locomoting animals (but less so for across populations or during ontogeny), the mechanisms at the physiological and cellular level are becoming clear. Lower mass-specific metabolic rates of larger species at rest are due to a) lower contents of expensive tissues (brains, liver, kidneys), and b) slower ion leak across membranes at least partially due to membrane composition, with lower ion pump ATPase activities. Lower mass-specific costs of larger species during locomotion are due to lower costs for lower-frequency muscle activity, with slower myosin and Ca++ ATPase activities, and likely more elastic energy storage. The evolutionary explanation(s) for hypometric scaling remain(s) highly controversial. One subset of evolutionary hypotheses relies on constraints on larger animals due to changes in geometry with size; for example, lower surface-to-volume ratios of exchange surfaces may constrain nutrient or heat exchange, or lower cross-sectional areas of muscles and tendons relative to body mass ratios would make larger animals more fragile without compensation. Another subset of hypotheses suggests that hypometric scaling arises from biotic interactions and correlated selection, with larger animals experiencing less selection for mass-specific growth or neurolocomotor performance. A additional third type of explanation comes from population genetics. Larger animals with their lower effective population sizes and subsequent less effective selection relative to drift may have more deleterious mutations, reducing maximal performance and metabolic rates. Resolving the evolutionary explanation for the hypometric scaling of metabolism and associated variables is a major challenge for organismal and evolutionary biology. To aid progress, we identify some variation in terminology use that has impeded cross-field conversations on scaling. We also suggest that promising directions for the field to move forward include: 1) studies examining the linkages between ontogenetic, population-level, and cross-species allometries, 2) studies linking scaling to ecological or phylogenetic context, 3) studies that consider multiple, possibly interacting hypotheses, and 4) obtaining better field data for metabolic rates and the life history correlates of metabolic rate such as lifespan, growth rate and reproduction.
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Affiliation(s)
- Jon F Harrison
- School of Life Sciences, Arizona State University, Tempe, AZ 85287-4501, USA
| | - Andrew Biewener
- Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, MA 02138, USA
| | - Joanna R Bernhardt
- Department of Zoology, University of British Columbia, Vancouver, BC V6T 1Z4, Canada
- Yale Institute for Biospheric Studies, New Haven, CT 06520, USA
| | - Joseph R Burger
- Department of Biology, University of Kentucky, Lexington, KY 40506, USA
| | - James H Brown
- Center for Evolutionary and Theoretical Immunology, The University of New Mexico, Albuquerque, NM 87131, USA
| | - Zach N Coto
- Department of Biology, Boston University, Boston, MA 02215, USA
| | - Meghan E Duell
- Department of Biology, The University of Western Ontario, London, ON N6A 3K7, Canada
| | - Michael Lynch
- Biodesign Center for Mechanisms of Evolution, Arizona State University, Tempe, AZ 85281, USA
| | - Emma R Moffett
- Department of Ecology and Evolution, University of California, Irvine, CA 92697, USA
| | - Tommy Norin
- DTU Aqua | National Institute of Aquatic Resources, Technical University of Denmark, Anker Engelunds Vej 1 Bygning 101A, 2800 Kgs. Lyngby, Denmark
| | - Amanda K Pettersen
- School of Life and Environmental Sciences, The University of Sydney, Sydney, NSW 2006, Australia
| | - Felisa A Smith
- Department of Biology, University of New Mexico, Albuquerque, NM 87131, USA
| | - Ummat Somjee
- Smithsonian Tropical Research Institute, Panama City, Panama
| | | | - Terrie M Williams
- Division of Physical and Biological Sciences, University of California, Santa Cruz, CA 95064, USA
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Rumbos CI, Athanassiou CG. The Superworm, Zophobas morio (Coleoptera:Tenebrionidae): A 'Sleeping Giant' in Nutrient Sources. JOURNAL OF INSECT SCIENCE (ONLINE) 2021; 21:6218202. [PMID: 33834209 PMCID: PMC8033247 DOI: 10.1093/jisesa/ieab014] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/22/2020] [Indexed: 05/20/2023]
Abstract
The aim of this review is to compile up-to-date information on the superworm, Zophobas morio (F.), regarding its biology and ecology, but also its further potential for use as a nutrient source for food and feed. We illustrate certain basic characteristics of the morphology and bio-ecology of this species, which is marginally considered as a 'pest' in durable amylaceous commodities. More recent data show that Z. morio can be a valuable nutrient and antimicrobial source that could be utilized further in insect-based feed and food production. The inclusion of this species in aquafeed has provided promising results in a wide range of feeding trials, both in terms of fish development and health. Additional data illustrate its potential for use in poultry, indicating that this species provides comparable results with those of other insect species that are used in feed. Moreover, Z. morio can be a viable waste management agent. This review aims to summarize the available data and underline data gaps for future research, toward the potential of the utilization of Z. morio for human food and animal feed. Based on the data presented, Z. morio appears to be a well-promising insect-based protein source, which potential still remains to be unfold.
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Affiliation(s)
- C I Rumbos
- Laboratory of Entomology and Agricultural Zoology, Department of Agriculture, Crop Production and Rural Environment, University of Thessaly, Volos, Greece
- Corresponding author, e-mail:
| | - C G Athanassiou
- Laboratory of Entomology and Agricultural Zoology, Department of Agriculture, Crop Production and Rural Environment, University of Thessaly, Volos, Greece
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Youngblood JP, VandenBrooks JM, Babarinde O, Donnay ME, Elliott DB, Fredette-Roman J, Angilletta MJ. Oxygen supply limits the chronic heat tolerance of locusts during the first instar only. JOURNAL OF INSECT PHYSIOLOGY 2020; 127:104157. [PMID: 33098860 DOI: 10.1016/j.jinsphys.2020.104157] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/30/2020] [Revised: 10/15/2020] [Accepted: 10/16/2020] [Indexed: 06/11/2023]
Abstract
Although scientists know that overheating kills many organisms, they do not agree on the mechanism. According to one theory, referred to as oxygen- and capacity-limitation of thermal tolerance, overheating occurs when a warming organism's demand for oxygen exceeds its supply, reducing the organism's supply of ATP. This model predicts that an organism's heat tolerance should decrease under hypoxia, yet most terrestrial organisms tolerate the same amount of warming across a wide range of oxygen concentrations. This point is especially true for adult insects, who deliver oxygen through highly efficient respiratory systems. However, oxygen limitation at high temperatures may be more common during immature life stages, which have less developed respiratory systems. To test this hypothesis, we measured the effects of heat and hypoxia on the survival of South American locusts (Schistocerca cancellata) throughout development and during specific instars. We demonstrate that the heat tolerance of locusts depends on oxygen supply during the first instar but not during later instars. This finding provides further support for the idea that oxygen limitation of thermal tolerance depends on respiratory performance, especially during immature life stages.
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Affiliation(s)
- Jacob P Youngblood
- School of Life Sciences, Arizona State University, Tempe, AZ 85287, USA.
| | | | | | - Megan E Donnay
- School of Life Sciences, Arizona State University, Tempe, AZ 85287, USA
| | - Deanna B Elliott
- School of Life Sciences, Arizona State University, Tempe, AZ 85287, USA
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