Mollet, H.F., O'Sullivan J.B., Welsh, J.P., Ezcurra, J.M., Greenwald S.A.
Monterey Bay Aquarium, 886 Cannery Row, Monterey, CA 93940

Preliminary captive biology of the pelagic stingray, Dasyatis (Pteroplatytrygon) violacea

Growth and feeding rates of 19 pelagic stingrays, {iDasyatis (Pteroplatytrygon) violacea} were measured during 3 phases in 1995 and 1996. 1. Fifteen females were fed 3 times/week (mean 1.24 %bodymass/day) in quarantine (T = 17.8 C) from March 1 to Oct. 18, 1995. Growth rates (mean 10.2 cm/yr, 3.1 kg/yr) and conversion factors (mean 9.3%) were seasonal. 2. During a transition period, interactions between pelagic stingrays and sunfish {iMola mola} were studied in the Open Bay Water exhibit (4600 m{+3}, T = 20 C). Daily feeding was introduced to minimize rays biting molas. 3. Four females and 2 males were fed daily (mean 2.5 %bodymass/day) in quarantine (T = 20 C) from March 19 to Dec. 10, 1996. Females had larger growth rates (mean 19.5 cm/yr, 11.1 kg/yr) than males (mean 12.0 cm/yr, 3.1 kg/yr) and one female reached record size (83 cm diskwidth, 23 kg). Feeding and growth rates were again seasonal. A stillborn litter, an aborted 5 cm diskwidth embryo, an eggcase with 7 infertile eggs, an empty eggcase suggested sperm storage of over 1 year and likely mating in captivity.

Keywords Pteroplatytrygon, Dasyatis violacea, growth rate, feeding rate, conversion factor, reproduction, stillborn litter, aborted embryo, eggcase, infertile egg

Abstract for 1997 AES Seattle Captive Elasmobranch Symposium

Added to home page : March. 15, 1997. HFM

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