Comprehensive thermal performance curves for yellow dung fly life history traits and the temperature-size-rule. (August 2021)

• Record Type: Journal Article
• Authors: Blanckenhorn, Wolf U.; Berger, David; Rohner, Patrick T.; Schäfer, Martin A.; Akashi, Hiroshi; Walters, Richard J.
• Is Part Of: Journal of thermal biology. Volume 100(2021)
• Publication Date: 2021-08
• Subjects: Body size -- Coexistence -- Development -- Growth -- Survival -- Temperature-size-rule -- Thermal niche; Thermobiology -- Periodicals; Temperature -- Periodicals; Biology -- Periodicals; Thermobiologie -- Périodiques; Thermobiology; Periodicals; 571.46
• DOI: 10.1016/j.jtherbio.2021.103069
• Languages: English
• ISSNs: 0306-4565

Abstract

ABSTRACT (239 words): Ambient temperature strongly determines the behaviour, physiology, and life history of all organisms. The technical assessment of organismal thermal niches in form of now so-called thermal performance curves (TPC) thus has a long tradition in biological research. Nevertheless, several traits do not display the idealized, intuitive dome-shaped TPC, and in practice assessments often do not cover the entire realistic or natural temperature range of an organism. We here illustrate this by presenting comprehensive sex-specific TPCs for the major (juvenile) life history traits of yellow dung flies ( Scathophaga stercoraria ; Diptera: Scathophagidae). This concerns estimation of prominent biogeographic rules, such as the temperature-size-rule (TSR), the common phenomenon in ectothermic organisms that body size decreases as temperature increases. S. stercoraria shows an untypical asymptotic TPC of continuous body size increase with decreasing temperature without a peak (optimum), thus following the TSR throughout their entire thermal range (unlike several other insects presented here). Egg-to-adult mortality (our best fitness estimator) also shows no intermediate maximum. Both may relate to this fly entering pupal winter diapause below 12 °C. While development time presents a negative exponential relationship with temperature, development rate and growth rate typify the classic TPC form for this fly. The hitherto largely unexplored close relative S. suilla with an even more arctic distribution showed very similar responses, demonstrating large overlap among two ecologically similar, coexisting dung fly species, thus implying limited utility of even complete TPCs for predicting species distribution and coexistence. Highlights: Survival of the common yellow dung fly increases asymptotically with decreasing temperature. Body size follows the temperature-size-rule throughout the entire thermal range. Development rate and growth rate display the classic dome-shaped thermal performance curve. Development or growth rate curves best serve to define the optimal growth and body size range. The closely related Scathophaga suilla shows very similar responses.