probably the california ray.. got this profile from SRC.
Care Profile on the California Stingray
Common Name: California Stingray
Scientific Name: Urobatis halleri
Alias: Round Stingray or Hallers Round Ray.
Maximum Adult Size: Maximum total length is about 22 inches (56 cm), and a maximum disc width of 12.2 inches (about 31 cm).
Average Adult Size: about 13.8 inches (35 cm) TL, or about 8.0 inches (20 cm)
Maximum Adult Weight: about 2.98 lbs (about 1.35 kg)
Size at Birth: about 5.1 (13 cm) total length.
Size at Sexual Maturity: about 10.2" (26cm) total length, about 5.9 (15 cm) disc width.
Age at Sexually Maturity: roughly 2 to 3 years (24-36 months)
Growth Rate: averages about 1.1 (2.8 cm) in disk width, & about 1.9 (4.8 cm) in total length per year.
Longevity of species: approx. 8 years.
Geographical Distribution: found in warm-temperate to sub- tropical ocean from Northern California, to the Pacific coast of Panama.
Habitat: A very abundant small sized warm-temperate to sub- tropical stingray - found to a depth of about 90 meters (295 ft). Prefers sandy shallow bays, rocky reefs, and grassy seabeds.
Diet: mostly bottom dwelling inverts, like shrimp, small crabs, & worms. Also known to feed on small fishes.
Activity level: a fairly active species of stingray. They are active daytime feeders. Basically a fairly harmless species, but like all species of stingrays, it does have a poisonous stinger.
Preferred Water Temperature & Conditions: They seem to prefer a water temperature range of 54-74 F (12-23 C). And Salinity range of 27-33 ppt or 1.020-1.024, and a pH range of 8.0-8.4.
Minimum recommend pond/tank size for a California Stingray: about 360 gallons or 8' long x 3' wide x 2' deep for a single California ray. For a small breeding group of 2-3 adults at least 600 gallons or 10 long x 4 wide x 2 deep.
The California Stingrays in captivity: This species does very well in captivity, and is often found in Home Aquariums and in some Public Aquariums. This species is generally very hardy, and usually acclimates quite well to captive life, provided that it has a good deal of swimming room. This species has also been known to breeding in captivity. Still this species seem to prefer cooler waters than most rays in it's genus.
Potential Problems: If this species is kept in tanks with water temps above 75 F (24C), the survival rate seems to drop drastically. So it is best kept in tanks with water temps below 72F.
Other Interesting Notes: Similar to the slightly smaller Cortez Rays, but it has pale spots instead of the brown ones of the Cortez.
Cited Sources:
Michael 2001 Aquarium Sharks & Rays,
Elasmodiver.com -
http://www.elasmodiver.com/round_stingray.htm
Fishbase.org -
http://www.fishbase.org/Summary/SpeciesSummary.php?id=2580
Flmnh.ufl.edu -
http://www.flmnh.ufl.edu/fish/Gallery/Desc...ndStingray.html,
.....!! but those guys hv no wings like cownose =(