Effects of ozone on evaporative water loss and thermoregulatory behavior of marine toads (Bufo marinus).
Ozone (O(3)) is a strong pulmonary irritant and causes a suite of respiratory tract inflammatory responses in humans and other mammals. In addition to lung injury, rodents exposed to O(3) exhibit a pronounced decrease in core body temperature at rest, which may offer a protective effect against O(3) damage. The effects of O(3) on other vertebrates have not been studied. Compared to individuals exposed to air (N=34), Bufo marinus toads exposed to O(3) (N=32) for 4 h lost 3.78 g body mass (adjusted mean from analysis of covariance, body mass mean+/-SD, 90.1+/-21.90 g). We tested the thermoregulatory responses of 22 toads in a thermal gradient 1, 24, and 48 h after 4-h exposure to air (N=11) or 0.8 ppm O(3) (N=11). Individual toad thermal preferences were also significantly repeatable across all trials (intraclass correlation=0.66, P <0.001). We did not observe a direct effect of O(3) exposure on the preferred body temperatures (PBT) of toads. However, O(3) exposure did have an indirect effect on selected temperatures. Ozone-exposed toads with higher evaporative water loss rates, in turn, also selected lower PBT, voluntary minimum, and voluntary maximum temperatures 24 h post-exposure. Ozone exposure may thus alter both water balance and thermal preferences in anuran amphibians.
Dohm
M R
MR
Department of Biology, University of Hawaii at Hilo, 200 West Kawili Street, Hilo, Hawaii 96270, USA.
Mautz
W J
WJ
Looby
P G
PG
Gellert
K S
KS
Andrade
J A
JA
D000280:Administration, Inhalation; D000818:Animals; D001273:Atmosphere Exposure Chambers; D001522:Behavior, Animal / Q000187:drug effects*; D001831:Body Temperature / Q000187:drug effects; D001833:Body Temperature Regulation / Q000187:drug effects*; D001835:Body Weight / Q000187:drug effects; D002024:Bufo marinus / Q000502:physiology*; D005260:Female; D008297:Male; D010126:Ozone / Q000008:administration & dosage*; D012044:Regression Analysis; D015203:Reproducibility of Results; D014870:Water Loss, Insensible / Q000187:drug effects*
D010126:Ozone