Format

Send to

Choose Destination
Sci Rep. 2015 Jun 1;5:10743. doi: 10.1038/srep10743.

Some like it hot: Thermal tolerance and oxygen supply capacity in two eurythermal crustaceans.

Author information

1
1] Department of Bioscience, Aarhus University, Aarhus, Denmark [2] College of Aquaculture and Fisheries, Can Tho University, Can Tho, Vietnam.
2
College of Aquaculture and Fisheries, Can Tho University, Can Tho, Vietnam.
3
Department of Bioscience, Aarhus University, Aarhus, Denmark.

Abstract

Thermal sensitivity of the cardiorespiratory oxygen supply capacity has been proposed as the cardinal link underlying the upper boundary of the temperature niche in aquatic ectotherms. Here we examined the evidence for this link in two eurythermal decapods, the Giant tiger shrimp (Penaeus monodon) and the European crayfish (Astacus astacus). We found that both species have a temperature resistant cardiorespiratory system, capable of maintaining oxygen delivery up to their upper critical temperature (Tcrit). In neither species was Tcrit reduced in hypoxia (60% air saturation) and both species showed an exponential increase in heart and gill ventilation rates up to their Tcrit. Further, failure of action potential conduction in preparations of A. astacus motor neurons coincided with Tcrit, indicating that compromised nervous function may provide the underlying determinant for Tcrit rather than oxygen delivery. At high temperatures, absolute aerobic scope was maintained in P. monodon, but reduced in A. astacus. However, A. astacus also displayed reduced exercise intensity indicating that impaired muscle performance with resulting reduced tissue oxygen demand may explain the reduced scope rather than insufficient oxygen supply capacity. This interpretation agrees with early literature on aquatic ectotherms, correlating loss of nervous function with impaired locomotion as temperatures approach Tcrit.

PMID:
26030412
PMCID:
PMC5377234
DOI:
10.1038/srep10743
[Indexed for MEDLINE]
Free PMC Article

Supplemental Content

Full text links

Icon for Nature Publishing Group Icon for PubMed Central
Loading ...
Support Center