California Rounds right? I have 4 females and 2 males in nearly 900 gallons and they show no signs of interest in mating (so far). The Aquarium Of The Pacific has had them fo years in their petting pool and they told me they have never matted. I have never seen anything on them matting in captivity and I have searched the web, but someone could be the first. What temp are you keeping them in? Depending where they are collected the temps can be different, some of mine were collected from Mexico but do not no where abouts. Some keep the ones from Cal. in the low 60s and I keep mine around 68 but with this hot weather its been a little higher. I read some place they move into the shallows to bread and then it would be warmer water there. One guy on another site who live south of LA says he see's them at discharge pipes for cooling factories and the temps are in the 80's there, but I'm sure thats not permanant. What size is you tank? They (rays) need to be at least 2+ years to breed also from what I have read and that would put them in the 5 1/2" range.