To examine the effect of water temperature on reproductive
physiology of round stingrays, a controlled laboratory experiment was
conducted. Captive male round stingrays were subjected to a controlled
water temperature regime to examine the influence on the production
and secretion of steroid hormones. Three groups of three males were
held in 950 L recirculating seawater tanks. Male round stingrays used in
this experiment were collected in July 2006 at Seal Beach, CA (USA).
Prior to housing in experimental tanks rays were held in an outdoor
4500 L recirculating tank and subjected to a natural photoperiod and
ambient water temperatures (13 °–20 °C) until March 2007. Nine rays