FW atlantic rays anyone?
- Thread starter SimonL
- Start date
Not many people keep them because of the amazing amount of ammonia and urea they produce because of how their osmoregulation system becomes compromised when placed in freshwater.
Although they stay small, keeping them in freshwater is like keeping a fish with the bio-load of a 24-36" stingray.. still need a big tank/filtration or a drip system to control ammonia and nitrates..
Although they stay small, keeping them in freshwater is like keeping a fish with the bio-load of a 24-36" stingray.. still need a big tank/filtration or a drip system to control ammonia and nitrates..
Just the kinda info I needed, I was thinking of adding one to my prehistoric collection. Is the ammonia level really that bad in FW? I actually converted them back to SW when we had them, but I've been debating keeping one in FW...
Edit: Just read several artciles about their osmoregulation...Wow, ten times more urine than their SW counterparts...
Edit: Just read several artciles about their osmoregulation...Wow, ten times more urine than their SW counterparts...
http://www.monsterfishkeepers.com/forums/showthread.php?t=106053&highlight=atlantic+ray
Heres a recent thread I made on the topic..
The problem is that, for in order to have a saltwater organism adapt to freshwater, like an atlantic ray or bullshark.. it must release an inordinate amount of ammonia and urea to counter balance what happens internally with their osmosis system.. I think that if they were unable to process water through their body in this way, the urea content in their blood would rise and kill them. ~ Not exactly sure, but something to this effect.
The other issue is, the higher the pH the more toxic ammonia is.. with these fish originating from the ocean and a pH of 8.5, it makes it hard for them to stay healthy with their own ammonia output, and need for higher pH. Ammonia toxicity at a pH of 8.5 is a thousand fold of the toxicity at a pH of 6.5.. When converted to FW, the pH must till stay high, or they will simply die.. If you try to lower the pH to combat the ammonia toxicity, it becomes very counterproductive and stressful..
So, in order to keep em happy.. you need a large volume of water to dilute the ammonia, and a great filtration system with a higher turnover rate to process that ammonia.. and without frequent water changes or a drip system, the nitrates will climb so rapidly that it can cause even further problems..
Don't get me wrong, they can be kept in home aquaria.. but their needs are hard to meet if all of that made sense. They would do best in something of 600g+, drip system.. or public aquarium.. or leave em in the ocean, where they belong.. (or river)
Heres a recent thread I made on the topic..
The problem is that, for in order to have a saltwater organism adapt to freshwater, like an atlantic ray or bullshark.. it must release an inordinate amount of ammonia and urea to counter balance what happens internally with their osmosis system.. I think that if they were unable to process water through their body in this way, the urea content in their blood would rise and kill them. ~ Not exactly sure, but something to this effect.
The other issue is, the higher the pH the more toxic ammonia is.. with these fish originating from the ocean and a pH of 8.5, it makes it hard for them to stay healthy with their own ammonia output, and need for higher pH. Ammonia toxicity at a pH of 8.5 is a thousand fold of the toxicity at a pH of 6.5.. When converted to FW, the pH must till stay high, or they will simply die.. If you try to lower the pH to combat the ammonia toxicity, it becomes very counterproductive and stressful..
So, in order to keep em happy.. you need a large volume of water to dilute the ammonia, and a great filtration system with a higher turnover rate to process that ammonia.. and without frequent water changes or a drip system, the nitrates will climb so rapidly that it can cause even further problems..
Don't get me wrong, they can be kept in home aquaria.. but their needs are hard to meet if all of that made sense. They would do best in something of 600g+, drip system.. or public aquarium.. or leave em in the ocean, where they belong.. (or river)
Thanks for the great info Miles...I've only kept them in SW. Damn, it was such a good feeder too lol. I suppose I'll have to get a Amazon ray, I just like the "arrowhead" shape better 
I presume the Asian "FW" rays have similar issues...
I presume the Asian "FW" rays have similar issues...
Makes me wonder if you could counter-regulate that by adding a ton of 'aquarium salt' instead of marine salt.. or a combination of both to make it a light brackish.. Would they produce less ammonia? H'rm.
But if you have FW prehistorics I wouldn't do it..
But if you have FW prehistorics I wouldn't do it..
SimonL;1398937; said:Thanks for the great info Miles...I've only kept them in SW. Damn, it was such a good feeder too lol. I suppose I'll have to get a Amazon ray, I just like the "arrowhead" shape better
and I think the Asian FW rays are okay, its only SW rays that migrate to FW that do that.. Only most of the Asian rays get HUGE!!!
Himantura oxyrhynchus is by far my favorite, but delicate and very, very expensive. My fav. SA ray is Paratrygon, alas also delicate lol.