Publication
Title
Diving in a warming world : the thermal sensitivity and plasticity of diving performance in juvenile estuarine crocodiles (**Crocodylus porosus**)
Author
Abstract
Air-breathing, diving ectotherms are a crucial component of the biodiversity and functioning of aquatic ecosystems, but these organisms may be particularly vulnerable to the effects of climate change on submergence times. Ectothermic dive capacity is thermally sensitive, with dive durations significantly reduced by acute increases in water temperature; it is unclear whether diving performance can acclimate/acclimatize in response to long-term exposure to elevated water temperatures. We assessed the thermal sensitivity and plasticity of fright-dive capacity in juvenile estuarine crocodiles ( Crocodylus porosus ; n  = 11). Crocodiles were exposed to one of three long-term thermal treatments, designed to emulate water temperatures under differing climate change scenarios (i.e. current summer, 28°C; moderate climate warming, 31.5°C; high climate warming, 35°C). Dive trials were conducted in a temperature-controlled tank across a range of water temperatures. Dive durations were independent of thermal acclimation treatment, indicating a lack of thermal acclimation response. Acute increases in water temperature resulted in significantly shorter dive durations, with mean submergence times effectively halving with every 3.5°C increase in water temperature ( Q10 0.17, P  < 0.001). Maximal dive performances, however, were found to be thermally insensitive across the temperature range of 2835°C. These results suggest that C. porosus have a limited or non-existent capacity to thermally acclimate sustained fright-dive performance. If the findings here are applicable to other air-breathing, diving ectotherms, the functional capacity of these organisms will probably be compromised under climate warming.
Language
English
Source (journal)
Conservation physiology
Conservation physiology
Publication
2015
ISSN
2051-1434
Volume/pages
3 :1 (2015) , 9 p.
Article Reference
cov054
ISI
000375202700001
Medium
E-only publicatie
Full text (Publisher's DOI)
Full text (open access)
UAntwerpen
Publication type
Subject
External links
Web of Science
Record
Identification
Creation 15.10.2018
Last edited 19.09.2021