1
|
Pacher K, Hernández-Román N, Juarez-Lopez A, Jiménez-Jiménez JE, Lukas J, Sevinchan Y, Krause J, Arias-Rodríguez L, Bierbach D. Thermal tolerance in an extremophile fish from Mexico is not affected by environmental hypoxia. Biol Open 2024; 13:bio060223. [PMID: 38314873 PMCID: PMC10868586 DOI: 10.1242/bio.060223] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2023] [Accepted: 11/27/2023] [Indexed: 02/07/2024] Open
Abstract
The thermal ecology of ectotherm animals has gained considerable attention in the face of human-induced climate change. Particularly in aquatic species, the experimental assessment of critical thermal limits (CTmin and CTmax) may help to predict possible effects of global warming on habitat suitability and ultimately species survival. Here we present data on the thermal limits of two endemic and endangered extremophile fish species, inhabiting a geothermally heated and sulfur-rich spring system in southern Mexico: The sulfur molly (Poecilia sulphuraria) and the widemouth gambusia (Gambusia eurystoma). Besides physiological challenges induced by toxic hydrogen sulfide and related severe hypoxia during the day, water temperatures have been previously reported to exceed those of nearby clearwater streams. We now present temperature data for various locations and years in the sulfur spring complex and conducted laboratory thermal tolerance tests (CTmin and CTmax) both under normoxic and severe hypoxic conditions in both species. Average CTmax limits did not differ between species when dissolved oxygen was present. However, critical temperature (CTmax=43.2°C) in P. sulphuraria did not change when tested under hypoxic conditions, while G. eurystoma on average had a lower CTmax when oxygen was absent. Based on this data we calculated both species' thermal safety margins and used a TDT (thermal death time) model framework to relate our experimental data to observed temperatures in the natural habitat. Our findings suggest that both species live near their thermal limits during the annual dry season and are locally already exposed to temperatures above their critical thermal limits. We discuss these findings in the light of possible physiological adaptions of the sulfur-adapted fish species and the anthropogenic threats for this unique system.
Collapse
Affiliation(s)
- Korbinian Pacher
- Department of Biology and Ecology of Fishes, Leibniz-Institute of Freshwater Ecology and Inland Fisheries, 12487 Berlin, Germany
- Faculty of Life Sciences, Albrecht Daniel Thaer-Institute, Humboldt University of Berlin, 10115 Berlin, Germany
| | - Natalia Hernández-Román
- División Académica de Ciencias Biológicas, Universidad Juárez Autónoma Tabasco, 86150 Villahermosa, Mexico
| | - Alejandro Juarez-Lopez
- División Académica de Ciencias Biológicas, Universidad Juárez Autónoma Tabasco, 86150 Villahermosa, Mexico
| | | | - Juliane Lukas
- Department of Biology and Ecology of Fishes, Leibniz-Institute of Freshwater Ecology and Inland Fisheries, 12487 Berlin, Germany
- Faculty of Life Sciences, Albrecht Daniel Thaer-Institute, Humboldt University of Berlin, 10115 Berlin, Germany
| | - Yunus Sevinchan
- Science of intelligence cluster has the state of a department at TU Berlin, Excellence Cluster Science of Intelligence, Technische Universität Berlin, 10587 Berlin, Germany
| | - Jens Krause
- Department of Biology and Ecology of Fishes, Leibniz-Institute of Freshwater Ecology and Inland Fisheries, 12487 Berlin, Germany
- Faculty of Life Sciences, Albrecht Daniel Thaer-Institute, Humboldt University of Berlin, 10115 Berlin, Germany
- Science of intelligence cluster has the state of a department at TU Berlin, Excellence Cluster Science of Intelligence, Technische Universität Berlin, 10587 Berlin, Germany
| | - Lenin Arias-Rodríguez
- División Académica de Ciencias Biológicas, Universidad Juárez Autónoma Tabasco, 86150 Villahermosa, Mexico
| | - David Bierbach
- Department of Biology and Ecology of Fishes, Leibniz-Institute of Freshwater Ecology and Inland Fisheries, 12487 Berlin, Germany
- Faculty of Life Sciences, Albrecht Daniel Thaer-Institute, Humboldt University of Berlin, 10115 Berlin, Germany
- Science of intelligence cluster has the state of a department at TU Berlin, Excellence Cluster Science of Intelligence, Technische Universität Berlin, 10587 Berlin, Germany
| |
Collapse
|
2
|
Klerks PL, Athrey GN, Leberg PL. Response to Selection for Increased Heat Tolerance in a Small Fish Species, With the Response Decreased by a Population Bottleneck. Front Ecol Evol 2019. [DOI: 10.3389/fevo.2019.00270] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
|
3
|
Ma G, Ma CS. Climate warming may increase aphids' dropping probabilities in response to high temperatures. JOURNAL OF INSECT PHYSIOLOGY 2012; 58:1456-1462. [PMID: 22940260 DOI: 10.1016/j.jinsphys.2012.08.012] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/16/2012] [Revised: 08/20/2012] [Accepted: 08/21/2012] [Indexed: 06/01/2023]
Abstract
Dropping off is considered an anti-predator behavior for aphids since previous studies have shown that it reduces the risk of predation. However, little attention is paid to dropping behavior triggered by other external stresses such as daytime high temperatures which are predicted to become more frequent in the context of climate warming. Here we defined a new parameter, drop-off temperature (DOT), to describe the critical temperature at which an aphid drops off its host plant when the ambient temperature increases gradually and slowly. Detailed studies were conducted to reveal effects of short-term acclimation (temperature, exposure time at high-temperature and starvation) on DOT of an aphid species, Sitobion avenae. Our objectives were to test if the aphids dropped off host plant to avoid high temperatures and how short-term acclimation affected the aphids' dropping behavior in response to heat stress. We suggest that dropping is a behavioral thermoregulation to avoid heat stress, since aphids started to move before they dropped off and the dropped aphids were still able to control their muscles prior to knockdown. The adults starved for 12 h had higher DOT values than those that were unstarved or starved for 6 h, and there was a trade-off between behavioral thermoregulation and energy acquisition. Higher temperatures and longer exposure times at high temperatures significantly lowered the aphids' DOT, suggested that the aphids avoid heat stress by dropping when exposed to high temperatures. Climate warming may therefore increase the aphids' dropping probabilities and consequently affect the aphids' individual development and population growth.
Collapse
Affiliation(s)
- Gang Ma
- Climate Change Biology Research Group, State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, China.
| | | |
Collapse
|
4
|
Ma G, Ma CS. Effect of acclimation on heat-escape temperatures of two aphid species: Implications for estimating behavioral response of insects to climate warming. JOURNAL OF INSECT PHYSIOLOGY 2012; 58:303-309. [PMID: 21939662 DOI: 10.1016/j.jinsphys.2011.09.003] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/24/2011] [Revised: 08/31/2011] [Accepted: 09/07/2011] [Indexed: 05/31/2023]
Abstract
An aphid usually stays at one feeding site for a long time to achieve its development and reproduction, while high temperatures can make it decide to escape from heat stress. Climate warming increases daily high-temperature both in degree and time. However, it remains unknown whether such heat-escape behavior will be influenced by those daily temperature changes. In this study, a wheat-leaf temperature gradient was created based on field microhabitat temperatures. We defined a parameter, heat-escape temperature (HET) to describe the critical temperature at which an aphid turns back when it walks along the gradient from mild temperature to high temperatures. HET indicates behavioral responses of the aphids to heat stress. Two aphid species, Sitobion avenae and Rhopalosiphum padi, main economic pests in temperate areas were selected as test insects. Detailed studies were conducted on the temperature gradient to reveal effects of acclimation temperature, time, and condition (temperature×time) on HET of both species. Results showed that HET decreased non-linearly (S. avenae: 41.4-38.6°C, R. padi: 41.3-39.4°C), when acclimation temperature increased from 25 to 36°C. For both species, HET declined linearly (S. avenae: 40.1-38.0°C, R. padi: 41.3-38.5°C) as acclimation time increased from 0.5 to 6h at 35°C, whereas HET descended non-linearly with reduction of acclimation time at 10°C. HET for both species acclimated under constantly warm conditions (future daily temperature) were significantly lower than those acclimated under gradually warm conditions (current daily temperature). These results suggest that aphids' heat-escape behavior is significantly influenced by brief thermal history, implying that aphids make decision to avoid heat stress based on the combination of temperature and exposure time and escape before they were hurt by high temperatures under the conditions of climate warming. Avoiding high temperatures may cost a lot of time and resources of aphids and thus potentially reduced growth, development, and reproduction. Changes in insect behaviors caused by ongoing climate warming and their ecological consequences should be more concerned.
Collapse
Affiliation(s)
- Gang Ma
- Climate Change Biology Research Group, State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, No. 2 Yuanmingyuan West Road, Haidian, Beijing, China.
| | | |
Collapse
|
5
|
Doyle CM, Leberg PL, Klerks PL. Heritability of heat tolerance in a small livebearing fish, Heterandria formosa. ECOTOXICOLOGY (LONDON, ENGLAND) 2011; 20:535-542. [PMID: 21373902 DOI: 10.1007/s10646-011-0624-2] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 02/21/2011] [Indexed: 05/30/2023]
Abstract
Climate change is expected to result in an increased occurrence of heat stress. The long-term population-level impact of this stress would be lessened in populations able to genetically adapt to higher temperatures. Adaptation requires the presence of genetically-based variation. At-risk populations may undergo strong declines in population size that lower the amount of genetic variation. The objectives of this study were to quantify the heritability of heat tolerance in populations of the least killifish, Heterandria formosa, and to determine if heritabilities were reduced following a population bottleneck. Heritabilities of heat tolerance were determined for two lines of each of two source populations; two bottlenecked lines (established with one pair of fish) and two regular lines. Heat tolerance was quantified as temperature-at-death (TAD), when fish acclimated at 28 °C were subjected to an increase in water temperature of 2 °C/day. Mid-parent/mean offspring regressions and full-sib analyses were used to estimate the heritability of TAD. Heritability estimates from parent/offspring regressions ranged from 0.185 to 0.462, while those from sib analyses ranged from 0 to 0.324, with an overall estimate of 0.203 (0.230 for the regular lines, 0.168 for bottlenecked ones). Fish from the bottlenecked line from one source population (but not the other) had a lower heritability than did those from the regular line. These results show that the populations tested had some potential for adaptation to elevated water temperatures, and that this potential may be reduced following a population bottleneck. This should not be construed as evidence that natural populations will not suffer negative consequences from global warming; this study only showed that these specific populations have some potential to adapt under a very specific set of conditions.
Collapse
Affiliation(s)
- Cathleen M Doyle
- Department of Biology, University of Louisiana at Lafayette, Box 42451, Lafayette, LA 70504-2451, USA
| | | | | |
Collapse
|