Rays and Salt

[lincolngoh]

During the bore, the salt water rushes back into the amazon, so I believe stingrays have can survive it.

I have breed sting ray under a year old and cure all minor problems with just clean water, soil additives and ketapan extract, so I don't really see a need for salt.

Perhaps a small amount is already added from my seafood diet.

 

[sodenoshirayuki]

adding one thing is alot easier than adding 2, so i dont really see a need for soil additives and ketapang extract, salt just seems so much more convenient

 

[ewurm]

What does wild potamotrygon have to do with their affinity to sodium?


Can one of you smart guys please explain to me what this specifically means, then?

despite the presence of branchial ion transport systems that exhibit surprisingly low affinity for external sodium and chloride and virtual insensitivity to the ionic composition of the acclimation water.

If I understand correctly, the gill systems have low natural attraction to salt and are insensitive to the amount of ions in the water. However:

"In the following discussion, we assume that ion
exchanges occur mainly at the gills, as in other fish.
However, given the large surface area and soft texture of
the well-perfused skin (which becomes pink with blood
flow during hypoxia), we cannot eliminate a significant
role for the skin in both ion uptake and efflux, and of
course for the renal system in ion efflux"


The animal takes up salt through the gills and skin like other fish. It gets rid of the excess salt through the skin and the kidneys. Given that in an environment that is more saline than they are adapted to, they would have to increase renal output to eliminate the excess salt. This is what concerns me, because there would be more strain on the kidneys. This is the same reason I recommend against keeping clown loaches in African Rift lake setups. They most definitely survive, but the increased renal activity to eliminate the various salt buffers that are added to the tank would most likely shorten the life span. As a treatment to alleviate problems, it's effective and justified, just like any other medication. But a tank with a continuously higher specific gravity would in my opinion shorten the life span of the fish.

 

[Miles]

If I understand correctly, the gill systems have low natural attraction to salt and are insensitive to the amount of ions in the water. However:

"In the following discussion, we assume that ion
exchanges occur mainly at the gills, as in other fish.
However, given the large surface area and soft texture of
the well-perfused skin (which becomes pink with blood
flow during hypoxia), we cannot eliminate a significant
role for the skin in both ion uptake and efflux, and of
course for the renal system in ion efflux"


The animal takes up salt through the gills and skin like other fish. It gets rid of the excess salt through the skin and the kidneys. Given that in an environment that is more saline than they are adapted to, they would have to increase renal output to eliminate the excess salt. This is what concerns me, because there would be more strain on the kidneys. This is the same reason I recommend against keeping clown loaches in African Rift lake setups. They most definitely survive, but the increased renal activity to eliminate the various salt buffers that are added to the tank would most likely shorten the life span.

Is renal gland activity the same between botia and potamotrygon? Get back to me

This might help.. Maybe I'm wrong? Last sentence is interesting...
http://rms1.agsearch.agropedia.affrc.go.jp/contents/JASI/pdf/society/38-1062.pdf

and no I am not confused with the rectal/renal thing..

As a treatment to alleviate problems, it's effective and justified, just like any other medication. But a tank with a continuously higher specific gravity would in my opinion shorten the life span of the fish.

Agree.

Why couldn't you say that in the first place? oh. I know why


Great info!

 

[Miles]

The paper you cited says they are limited in nature to three parts per thousand salinity.

The paper I cited said this, too..
potamotrygonid rays have lost their ability to live in seawater and are restricted in nature to waters with a salinity of less than 3 ppt

 

[Miles]

The piece says: ,1st sentence of the summary:
"Stingrays of the family Potamotrygonidae are the only stenohaline freshwater elasmobranchs........"
So the article defines them from the get-go:
Wiki defines stenohaline:"Stenohaline describes an organism, usually fish, that cannot handle a wide fluctuation in the salt content of water."

Marine Salt is different than Aquarium Salt, David..

Of course.. Bull Sharks and Atlantic rays would be a great example of a non-stenohaline freshwater elasmobranch? or wait.. how many freshwater elasmobranch are there? Get your books out!

 

[abortedsoul]

I need to make that trip to the amazon.

x2

 

[lincolngoh]

adding one thing is alot easier than adding 2, so i dont really see a need for soil additives and ketapang extract, salt just seems so much more convenient

I dislike salt, it's just one element, so I recently started adding a kind of extract from mountain clay which contains a more complete selection of many naturally minerals which is missing from tap water. It comes packaged, has a fantastic shelf life and it's hassle free to add.

I do add humic acids too from many different leaves & peat, Ketapan is just one of them, and these are much more difficult to prepare... as I have to laundry bag the leaves and remove the soaked leaves after awhile.

I try to duplicate the water that comes from the leaf littered rivers and down stream from the mountains.

 

[Miles]

I dislike salt, it's just one element, so I recently started adding a kind of extract from mountain clay which contains a more complete selection of many naturally minerals which is missing from tap water. It comes packaged, has a fantastic shelf life and it's hassle free to add.

I do add humic acids too from many different leaves & peat, Ketapan is just one of them, and these are much more difficult to prepare... as I have to laundry bag the leaves and remove the soaked leaves after awhile.

I try to duplicate the water that comes from the leaf littered rivers and down stream from the mountains.

You should start a thread on alternative water additives for stingrays, and maybe why or why not you think certain ones are beneficial...! That would be cool

 

[ewurm]

The paper I cited said this, too..
potamotrygonid rays have lost their ability to live in seawater and are restricted in nature to waters with a salinity of less than 3 ppt

What's your point?

I think you're missing a key point that the statement you made and the paper you cited have nothing to do with each other. The paper is about the rays adaption to ion-poor blackwater, not their "affinity for salt" or whether or not it "bothers them". I say we skip the rest of this thread and go straight to bomzanza.