ARPHA Conference Abstracts : Conference Abstract
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Conference Abstract
Limited thermal acclimation capacity in cave beetles
expand article infoSusana Pallarés‡, Ignacio Ribera§, Aitor Montes|, Andrés Millán, Valeria Rizzo#, Jordi Comas¤, David Sánchez-Fernández‡
‡ Universidad de Castilla-La Mancha, Toledo, Spain
§ Instituto de Biología Evolutiva, Barcelona, Spain
| Cuevas de Oñati-Arrikrutz, Oñati (Guipuzcoa), Spain
¶ University of Murcia, Murcia, Spain
# Unaffiliated, Roma, Italy
¤ Unaffiliated, Barcelona, Spain
Corresponding author: Susana Pallarés (susana.pallares@um.es)
Received: 18 Sep 2018 | Published: 19 Sep 2018
© 2018 Susana Pallarés, Ignacio Ribera, Aitor Montes, Andrés Millán, Valeria Rizzo, Jordi Comas, David Sánchez-Fernández
This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Citation: Pallarés S, Ribera I, Montes A, Millán A, Rizzo V, Comas J, Sánchez-Fernández D (2018) Limited thermal acclimation capacity in cave beetles. ARPHA Conference Abstracts 1: e29869. https://doi.org/10.3897/aca.1.e29869
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Abstract

Thermal tolerance is a key vulnerability factor for species that cannot cope with changing conditions by behavioural adjustments or dispersal, such as subterranean species. Previous studies of thermal tolerance in cave beetles suggest that these species may have lost some of the thermoregulatory mechanisms common in temperate insects, and appear to have a very limited thermal acclimation ability. However, it might be expected that both thermal tolerance and acclimation ability should be related with the degree of specialization to deep subterranean environments, being more limited in highly specialized species. To test this hypothesis, we use an experimental approach to determine the acclimation capacity of cave beetles within the tribe Leptodirini (family Leiodidae) with different degrees of specialization to the deep subterranean environment. For this, we acclimate groups of individuals at

  1. a temperature close to their upper thermal limit (20ºC) or
  2. a control temperature (approximately that of the cave in which they were found) for 2 or 10 days (short- vs. long-term acclimation).

Upper thermal limits (heat coma temperature, HC) are then measured for each individual using a ramping protocol (rate of increase of 1ºC/min) combined with infrared thermography and video recording. Preliminary results in a deep subterranean species (Speonomidius crotchi, with an intermediate degree of specialization) showed no significant effect of acclimation temperature in HC at any of the exposure times. Such reduced thermal plasticity could be also expected for other highly specialized subterranean species. The potential implications of these findings for subterranean biodiversity in a climate change context are discussed.

Presenting author

Susana Pallarés