Reprodution of the Cownose ray, Rhinoptera bonasus Mitchill, 1815 (Elasmobranchii, Rhinopteridae), in captivity and newborn care.
Braz. J. Biol. vol.68 no.4 São Carlos Nov. 2008
Since its opening in 1996, the Ubatuba Aquarium, located in Ubatuba, São Paulo State, Brazil, has three specimens of the cownose ray, one male and two females, held in an 85000l tank. It is a semi-open system with biological and mechanical filtration, skimmer, and UV and ozone water sterilization. The tank is illuminated by metal halide lamps and for half the day by direct sunlight.
In September 2003, courtship behavior was observed, and only one quick copulation during the afternoon, with one clasper insertion followed by white liquid spreading out from the female cloacae. During courtship, mating and gestation period, average physical and chemical parameters values monitored in the water tank were: pH7.3, 0.25 ppm NH3, 0.25 ppm NO2, salinity 34 ppm and temperature 26 °C. Finally, after 13 months gestation, in November 1st 2004, at dawn, the female gave birth to a male offspring.
The pup was born with 38 cm disc width and weighing 3.75 kg.