Differences in Corticosterone Release Rates of Larval Spring Salamanders (<i>Gyrinophilus porphyriticus</i>) in Response to Native Fish Presence
Invasive fish predators are an important factor causing amphibian declines and may have direct and indirect effects on amphibian survival. For example, early non-lethal exposure to these stressors may reduce survival in later life stages, especially in biphasic species. In amphibians, the glucocorti...
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MDPI AG
2022-03-01
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| Series: | Biology |
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| Online Access: | https://www.mdpi.com/2079-7737/11/4/484 |
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| author | Amanda R. Bryant Caitlin R. Gabor Leah K. Swartz Ryan Wagner Madaline M. Cochrane Winsor H. Lowe |
| author_facet | Amanda R. Bryant Caitlin R. Gabor Leah K. Swartz Ryan Wagner Madaline M. Cochrane Winsor H. Lowe |
| author_sort | Amanda R. Bryant |
| collection | DOAJ |
| description | Invasive fish predators are an important factor causing amphibian declines and may have direct and indirect effects on amphibian survival. For example, early non-lethal exposure to these stressors may reduce survival in later life stages, especially in biphasic species. In amphibians, the glucocorticoid hormone corticosterone is released by the hypothalamo–pituitary–interrenal axis (HPI), as an adaptive physiological response to environmental stressors. The corticosterone response (baseline and response to acute stressors) is highly flexible and context dependent, and this variation can allow individuals to alter their phenotype and behavior with environmental changes, ultimately increasing survival. We sampled larvae of the spring salamander (<i>Gyrinophilus porphyriticus</i>) from two streams that each contained predatory brook trout (<i>Slavelinus fontinalis</i>) in the lower reaches and no predatory brook trout in the upper reaches. We measured baseline and stress-induced corticosterone release rates of larvae from the lower and upper reaches using a non-invasive water-borne hormone assay. We hypothesized that corticosterone release rates would differ between larvae from fish-present reaches and larvae from fish-free reaches. We found that baseline and stressor-induced corticosterone release rates were downregulated in larvae from reaches with fish predators. These results indicate that individuals from reaches with predatory trout are responding to fish predators by downregulating corticosterone while maintaining an active HPI axis. This may allow larvae more time to grow before metamorphosing, while also allowing them to physiologically respond to novel stressors. However, prolonged downregulation of corticosterone release rates can impact growth in post-metamorphic individuals. |
| first_indexed | 2024-03-09T11:09:30Z |
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| issn | 2079-7737 |
| language | English |
| last_indexed | 2024-03-09T11:09:30Z |
| publishDate | 2022-03-01 |
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| record_format | Article |
| series | Biology |
| spelling | doaj.art-ded5078f7fc44102a896b183153cf1eb2023-12-01T00:49:48ZengMDPI AGBiology2079-77372022-03-0111448410.3390/biology11040484Differences in Corticosterone Release Rates of Larval Spring Salamanders (<i>Gyrinophilus porphyriticus</i>) in Response to Native Fish PresenceAmanda R. Bryant0Caitlin R. Gabor1Leah K. Swartz2Ryan Wagner3Madaline M. Cochrane4Winsor H. Lowe5Department of Biology, Texas State University, San Marcos, TX 78666, USADepartment of Biology, Texas State University, San Marcos, TX 78666, USAMontana Freshwater Partners, Livingston, MT 59047, USASchool of Environment and Natural Resources, The Ohio State University Columbus, Columbus, OH 43210, USADivision of Biological Sciences, University of Montana, Missoula, MT 59812, USADivision of Biological Sciences, University of Montana, Missoula, MT 59812, USAInvasive fish predators are an important factor causing amphibian declines and may have direct and indirect effects on amphibian survival. For example, early non-lethal exposure to these stressors may reduce survival in later life stages, especially in biphasic species. In amphibians, the glucocorticoid hormone corticosterone is released by the hypothalamo–pituitary–interrenal axis (HPI), as an adaptive physiological response to environmental stressors. The corticosterone response (baseline and response to acute stressors) is highly flexible and context dependent, and this variation can allow individuals to alter their phenotype and behavior with environmental changes, ultimately increasing survival. We sampled larvae of the spring salamander (<i>Gyrinophilus porphyriticus</i>) from two streams that each contained predatory brook trout (<i>Slavelinus fontinalis</i>) in the lower reaches and no predatory brook trout in the upper reaches. We measured baseline and stress-induced corticosterone release rates of larvae from the lower and upper reaches using a non-invasive water-borne hormone assay. We hypothesized that corticosterone release rates would differ between larvae from fish-present reaches and larvae from fish-free reaches. We found that baseline and stressor-induced corticosterone release rates were downregulated in larvae from reaches with fish predators. These results indicate that individuals from reaches with predatory trout are responding to fish predators by downregulating corticosterone while maintaining an active HPI axis. This may allow larvae more time to grow before metamorphosing, while also allowing them to physiologically respond to novel stressors. However, prolonged downregulation of corticosterone release rates can impact growth in post-metamorphic individuals.https://www.mdpi.com/2079-7737/11/4/484amphibianstress physiologycoping capacityglucocorticoidspredation |
| spellingShingle | Amanda R. Bryant Caitlin R. Gabor Leah K. Swartz Ryan Wagner Madaline M. Cochrane Winsor H. Lowe Differences in Corticosterone Release Rates of Larval Spring Salamanders (<i>Gyrinophilus porphyriticus</i>) in Response to Native Fish Presence Biology amphibian stress physiology coping capacity glucocorticoids predation |
| title | Differences in Corticosterone Release Rates of Larval Spring Salamanders (<i>Gyrinophilus porphyriticus</i>) in Response to Native Fish Presence |
| title_full | Differences in Corticosterone Release Rates of Larval Spring Salamanders (<i>Gyrinophilus porphyriticus</i>) in Response to Native Fish Presence |
| title_fullStr | Differences in Corticosterone Release Rates of Larval Spring Salamanders (<i>Gyrinophilus porphyriticus</i>) in Response to Native Fish Presence |
| title_full_unstemmed | Differences in Corticosterone Release Rates of Larval Spring Salamanders (<i>Gyrinophilus porphyriticus</i>) in Response to Native Fish Presence |
| title_short | Differences in Corticosterone Release Rates of Larval Spring Salamanders (<i>Gyrinophilus porphyriticus</i>) in Response to Native Fish Presence |
| title_sort | differences in corticosterone release rates of larval spring salamanders i gyrinophilus porphyriticus i in response to native fish presence |
| topic | amphibian stress physiology coping capacity glucocorticoids predation |
| url | https://www.mdpi.com/2079-7737/11/4/484 |
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