Aquatic insects dealing with dehydration: do desiccation resistance traits differ in species with contrasting habitat preferences?
- Published
- Accepted
- Subject Areas
- Ecology, Entomology
- Keywords
- water content, Coleoptera, lotic, water loss, cuticle, salinity, Enochrus, lentic
- Copyright
- © 2016 Pallarés et al.
- Licence
- This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, reproduction and adaptation in any medium and for any purpose provided that it is properly attributed. For attribution, the original author(s), title, publication source (PeerJ Preprints) and either DOI or URL of the article must be cited.
- Cite this article
- 2016. Aquatic insects dealing with dehydration: do desiccation resistance traits differ in species with contrasting habitat preferences? PeerJ Preprints 4:e2087v1 https://doi.org/10.7287/peerj.preprints.2087v1
Abstract
Background. Desiccation resistance shapes the distribution of terrestrial insects at multiple spatial scales. However, responses to desiccation stress have been poorly studied in aquatic groups, despite their potential role in constraining their distribution and diversification, particularly in arid and semi-arid regions. Methods. We examined desiccation resistance in adults of four congeneric water beetle species (Enochrus, family Hydrophilidae) with contrasting habitat specificity (lentic vs lotic systems and different salinity optima from fresh- to hypersaline waters).We measured survival, recovery capacity and key traits related to desiccation resistance (fresh mass, % water content, % cuticle content and water loss rate) under controlled exposure to desiccation, and explored their variability within and between species. Results. Meso- and hypersaline species were more resistant to desiccation than freshwater and hyposaline ones, showing significantly lower water loss rates and higher water content. No clear patterns in desiccation resistance traits were observed between lotic and lentic species. Intraspecifically, water loss rate was positively related to specimens’ initial % water content, but not to fresh mass or % cuticle content, suggesting that the dynamic mechanism controlling water loss is mainly regulated by the amount of body water available. Discussion. Our results support previous hypotheses suggesting that the evolution of desiccation resistance is associated with the colonization of saline habitats by aquatic beetles. The interespecific patterns observed in Enochrus also suggest that freshwater species may be more vulnerable than saline ones to drought intensification expected under climate change in semi-arid regions such as the Mediterranean Basin.
Author Comment
This is a submission to PeerJ currently under review.