were placed into experimental tanks and three were left in the holding
tank as a control. Water temperature loggers were placed into both the
control and experimental tanks to monitor water temperatures. Rays in
the treatment tanks were subjected to 2 weeks of ambient water
temperature (18 °–20 °C) after which the water temperature was
increased to 25 °C for 3 weeks and finally reduced to 14 °C for three
weeks. Blood (200 μL) was sampled from each ray every week via caudal
venipuncture. Weekly serum samples were analyzed for T and 11-KT
using radioimmuoassay and enzyme immunoassay. Results from this
experiment were compared to concentrations observed during seasonal
monthly sampling from Seal Beach to assess reproductive state. One way
ANOVAs with the Newman–Keuls pair-wise comparison test with a
significance of α=0.05 were used to compare the differences between
treatment groups and weeks.