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Estuarine key-species in a changing world: how potential vulnerable stages of fiddler crabs respond to global warming and acidification?

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Juan Carlos Farias Pardo
Total Authors: 1
Document type: Master's Dissertation
Press: Botucatu. 2018-12-20.
Institution: Universidade Estadual Paulista (Unesp). Instituto de Biociências. Botucatu
Defense date:
Advisor: Stefano Cannicci; Tânia Marcia Costa

The Anthropogenic climate change affects the functioning and structure of ecosystems. Global warming and acidification are among the main stressors. Coastal and estuarine habitats are dynamic, and their organisms are directly affected by environmental abiotic changes. In the present study, we verified how potentially vulnerable stages of estuarine ectotherms respond to climate variations. Using fiddler crabs as our model, a key-group in estuarine habitat conformation, we evaluated morphological and physiological responses under temperature increase and pH decrease scenarios. Initially, we characterized the environment that embryos of the Atlantic fiddler crab Leptuca thayeri are developed. Temperature, pH, and salinity of their microhabitat (burrows) differed from the surrounding environment. Embryonic development was affected by both stressors: temperature increase accelerated their development and decreased survivorship for either low and control pH; the response variables ammonia concentration and egg volume followed the synergetic effect of pH and temperature. In an interspecific approach, we experimentally showed that the thermal sensitivity of ovigerous females is species-specific. Ovigerous females of Gelasimus borealis were more sensitive to temperature increase than non-ovigerous, yet for L. thayeri the thermal tolerance remained similar regardless reproductive status. The mean temperature measured in their natural habitat was lower than the thermal limits of both species, with extremes above their limits. In this sense, we showed that vulnerable stages of fiddler crabs are sensitive to predicted abiotic changes and their responses may vary from individuals to species according to their life-stage. (AU)

FAPESP's process: 17/00802-0 - Estuarine keystone species in a changing world: how early life-history stages of fiddler crabs will respond to coastal ocean warming and acidification?
Grantee:Juan Carlos Farias Pardo
Support Opportunities: Scholarships in Brazil - Master