Effects of Water Loss on New Mexico Spadefoot Toad (Spea multiplicata) Development, Spleen Cellularity, and Corticosterone Levels.


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Type
Article
Change log
Authors
Bagwill, April L 
Lovern, Matthew B 
Worthington, Thomas A 
Smith, Loren M 
McMurry, Scott T 
Abstract

Amphibian metamorphosis is complex and larval morphology and physiology are completely restructured during this time. Amphibians that live in unpredictable environments are often exposed to stressors that can directly and indirectly alter physiological systems during development, with subsequent consequences (carryover effects) later in life. In this study, we investigated the effects of water level reduction on development rate, spleen size and cellularity, and examined the role of corticosterone levels in premetamorphic, metamorphic, and postmetamorphic New Mexico spadefoot toads (Spea multiplicata). Based on previous studies, we hypothesized that declining water level would increase tadpole developmental rate, but with the trade-off of increasing corticosterone to a level that would subsequently affect spleen size and cellularity, thus prolonging potential immunological suppression. Declining water levels increased developmental rate by 3 days; however, there were no significant body size effects. Corticosterone (CORT) was negatively correlated with total length, snout vent length, body weight, and spleen weight at metamorphosis, suggesting that size at metamorphosis and the immune system may be affected by excessive CORT levels. When compared to other studies, our results support the view that multiple factors may be acting as stressors in the field affecting amphibian responses, and simple pathways as tested in this study may not adequately represent field conditions.

Description
Keywords
Animals, Anura, Corticosterone, Female, Immune System, Male, Metamorphosis, Biological, Organ Size, Spleen, Stress, Physiological, Water
Journal Title
J Exp Zool A Ecol Genet Physiol
Conference Name
Journal ISSN
1932-5223
1932-5231
Volume Title
325
Publisher
Wiley
Rights
All rights reserved