title: Standard oxygen consumption of seasonally acclimatized cownose rays, Rhinoptera bonasus (Mitchill 1815), in the northern Gulf of Mexico.
abstract: Standard oxygen consumption rate (MO(2)) was determined for 19 cownose rays (Rhinoptera bonasus) using flow-through respirometry. Rays ranged in size from 0.4 to 8.25 kg (350-790 mm DW). Respirometry experiments were conducted on seasonally acclimatized rays at temperatures from 19.0 to 28.8 degrees C. Estimates of mass-dependent MO(2) ranged from 55.88 mg O(2) kg(-1) h(-1) for an 8.25 kg ray to 332.75 mg O(2) kg(-1) h(-1) for a 2.2 kg animal at 22-25 degrees C. Multiple regression analysis examining the effect of temperature, salinity, and mass on standard mass-independent MO(2) found temperature (P < 0.01), and mass (P < 0.0001) to have a significant effect on oxygen consumption, whereas salinity did not (P > 0.05). Q (10) was calculated as 2.33 (19-28 degrees C), falling between the estimates determined for two other batoid species, the bull ray (Myliobatos aquila; Q (10) = 1.87) and the bat ray (Myliobatis californica; Q (10) = 3.00). The difference in the Q (10) estimates may be attributed to the use of seasonally acclimatized as opposed to laboratory-acclimated animals.
authors.affiliation: Coastal Fisheries Institute, Louisiana State University, Baton Rouge, Louisiana, 70803-7503, USA, Julie.neer@noaa.gov.
authors.forename: J A
authors.initials: JA
authors.lastname: Neer
authors.forename: J K
authors.initials: JK
authors.lastname: Carlson
authors.forename: B A
authors.initials: BA
authors.lastname: Thompson