Becuase of the excess urea (pure ammonia) being produced in freshwater, you would need a tank 10 times the size than if it was a saltwater tank just to put up with all that extra ammonia. Either way you would need a huge tank if not bigger than for a "saltwater" atlantic ray. The excess urea would be no problem in the wild as the bodies of water are all connected, but it makes a huge difference in a tank.
Newbie with stingrays (Dasyatis sabina) Help !
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As for there size..........
Stingrays in Florida coastal lagoons reportedly reach a maximum disc width of 12.8 inches (32.6 cm) for males and 14.6 inches (37 cm) for females. Males mature around 7.9 inches (20 cm) disc width with females maturing at 9.4 inches (24 cm) disc width. In Freshwater populations females mature at 8.7 inches (22 cm) disc width and males mature at 8.3 inches (21 cm) disc width. Males are commonly 27 cm (Width of Disc) in length when caught/marketed, but may be as large as 61 cm (Width of Disc).
Stingrays in Florida coastal lagoons reportedly reach a maximum disc width of 12.8 inches (32.6 cm) for males and 14.6 inches (37 cm) for females. Males mature around 7.9 inches (20 cm) disc width with females maturing at 9.4 inches (24 cm) disc width. In Freshwater populations females mature at 8.7 inches (22 cm) disc width and males mature at 8.3 inches (21 cm) disc width. Males are commonly 27 cm (Width of Disc) in length when caught/marketed, but may be as large as 61 cm (Width of Disc).
to keep the rays in fresh water i would recommend at least a 500 gal or get some smaller species of rays like the south american ones theyre harder to find but easier to manage.. ive personally keep fresh water rays from the charleston river in flordia in a 300 gal with good results but they are smaller and completely adapted to a salt free environment for millions of years good luck
are you not understanding that in fw they produce 10x the urine, something a river could handle, but an average tank could not? yes the rays CAN live in fw, but the system will need to be much much larger.Fish Room Plus;2851833; said:
i just love repeating myself.
to say that the rays live their full lives in a fw river, but not explain how this can be done in a closed system is a waste of time.
No one is saying they cant adapt. The point is, when they're in freshwater, you'd need a much bigger tank as they produce extra urea...someone needs to read...
Are you 2 just thnck headed?
They never see salt, why would you change this?? Why would there urin output change?? They are born, they reproduce & die in the same fresh water st. johns river, never seeing salt water.
They never see salt, why would you change this?? Why would there urin output change?? They are born, they reproduce & die in the same fresh water st. johns river, never seeing salt water.
guess sales stay up on atlantic rays when people try and hide the truth bout their ammonia output in FW.
LOL i wonder who is really the thick headed one here...How about this, you go get yourself a "freshwater" atlantic ray, and then go put it in a tank and treat it as any normal freshwater ray and see if your tank starts smelling like a zoo.Fish Room Plus;2851883; said:
[SIZE=+1]http://nersp.nerdc.ufl.edu/~pmpie/dsabina.html[/SIZE]
[SIZE=+1]Even though it is not likely that the freshwater stingray populations in the St. Johns River migrate to the ocean, they have not lost the physiological ability to do so. I have conducted experiments that demonstrate freshwater D. sabina from Lake Jesup can acclimate to sea water (30 ppt salinity). They are able to do this because even in fresh water their kidneys reabsorb urea. Unlike the stenohaline freshwater South American Stingrays of the family Potamotrygonidae, D. sabina still has the neprhon segment associated with urea retention. So, in essence these animals are "primed" for return to salt water by reabsorbing more urea when faced with a salinity increase.[/SIZE] [SIZE=+1]This urea retention, however, does have some tradeoffs. In fresh water, the stingrays still retain about 50% of their urea leading to a total osmotic pressure that is 15 times greater than their environment. So these animals face a very large osmotic uptake of water. To compensate for the influx of water, these stingrays have a considerable urine flow rate which is almost 10 times higher than those found in marine individuals.[/SIZE]
nuff said!
[SIZE=+1]Even though it is not likely that the freshwater stingray populations in the St. Johns River migrate to the ocean, they have not lost the physiological ability to do so. I have conducted experiments that demonstrate freshwater D. sabina from Lake Jesup can acclimate to sea water (30 ppt salinity). They are able to do this because even in fresh water their kidneys reabsorb urea. Unlike the stenohaline freshwater South American Stingrays of the family Potamotrygonidae, D. sabina still has the neprhon segment associated with urea retention. So, in essence these animals are "primed" for return to salt water by reabsorbing more urea when faced with a salinity increase.[/SIZE] [SIZE=+1]This urea retention, however, does have some tradeoffs. In fresh water, the stingrays still retain about 50% of their urea leading to a total osmotic pressure that is 15 times greater than their environment. So these animals face a very large osmotic uptake of water. To compensate for the influx of water, these stingrays have a considerable urine flow rate which is almost 10 times higher than those found in marine individuals.[/SIZE]
nuff said!
