Brackish water and growth rates

[cutegecko3]

I have begun brackish water experiments with marine invertebrates predicting a fitness gain with lower salinity. Logically, sodium is unhealthy for any organism at high levels.

Cell chemistry

The ratio of potassium to sodium in the cells of all organisms is the complete opposite of current NSW levels.

"In order to maintain the cell membrane potential, cells keep a low concentration of sodium ions and high levels of potassium ions within the cell (intracellular). The sodium-potassium pump moves 3 sodium ions out and moves 2 potassium ions in, thus in total removing one positive charge carrier from the intracellular space. Please see Mechanism for details.
Not only the mechanism of the sodium-potassium pump alone is responsible for the generation of the resting membrane potential. Also the selective permeability of the cell's plasma membrane for the different Ions plays an important role. All mechanisms involved are explained in the main article on generation of the resting membrane potential."

http://en.wikipedia.org/wiki/Na+/K+-ATPase

Experiments

"Echinometra lucunter tolerated a SW salinity
reduction from full-strength SW (35 ppt) down to
25 ppt, with no mortality detected after 5 d. When
the salinity was raised by the same amount, a difference
of 10 g/kg of salt (a 29% change) to 45
ppt, mortality occurred after 2-3 d of exposure.
After 40 h in 45 ppt, all urchins were alive, but their
spines and ambulacral feet had lost their tone, the
peristomial membrane was retracted, and the teeth
of the lantern were more exposed."

http://zoolstud.sinica.edu.tw/Journals/46.2/203.pdf

This experiment only lasted for five days, but it did prove that lower salinity was tolerable.

"The regulation
of the somatotropic axis was studied by measuring pituitary
growth hormone expression and liver IGF-I expression in salinityadapted
fish. The expression amounts of both genes involved in the
somatotropic axis were highest in fish maintained at an isoosmotic
salinity. The results of this study provide new information on key
molecular processes involved in euryhalinity of fish."

http://ajpregu.physiology.org/content/287/5/R1054.full.pdf

This experiment showed a higher growth hormone expression in (12 PPT) over NSW levels.

My experiments have shown faster growth rates in zoanthids when they were acclimated to 1.018.

Here are some of the new polyps.

I'm currently fully acclimated to 1.016 for two weeks and all phyla (Coralline algae, anemones, starfish, zoanthids, isopods, amphipods, isopods) are still growing strong.



Enjoy.

 

[91Atrac]

That's high brackish. You trying to see how low the salt can be for inverts to still fluorish?


Sent from Qbabys Tapatalk.

 

[FrogfishFeeder]

Ive been acclimating FW ghost shrimps to full SW over the last 2 months.
Im currently at full strength and holding, matching the system Ill put them in, at 1.026.

I started with 30 shrimps, still have 20(other 10 got fed to fish), and all my females that arent full of eggs just released their young.
They are thriving in the SW, and the breeding proves it.

My only concern is for when I temp acclimate them, because right now they are at roomtemp ~60, but bumping them up to 78 could be the deciding factor if this will work long term.
In effect, I have slowed their metabolism(my theory) with the cool water, and the 78 degree water is gonna speed it back up.

We will see.

I just dont buy the fact that salt is not good for animals that evolved to live in it.
Sodium like we eat(thats bad for us) is refined and processed.....

 

[billsreef]

Keep in mind the species in those papers are all naturally adapted to and found in those lower salinities. As a result, saying they do well or better at the lower salinty is a far cry from saying oceanic species that are not normally found in those lower salinities will do better in lower salinity.

Also FrogfishFeeders ghost shrimp are naturally found in both FW and full SW, as well as everything in between.

BTW for interesting twist, some FW species are known to run to SW and grow bigger in SW than in full fresh.

 

[cutegecko3]

That's high brackish. You trying to see how low the salt can be for inverts to still fluorish?


Sent from Qbabys Tapatalk.

No. Cells of all living organisms have a minute amount of sodium in them and given the fact that, over time, sodium levels increase from river deposits was rather conclusive to me that they began their origin in much lower salinity than NSW levels.

Enjoy.

 

[cutegecko3]

Keep in mind the species in those papers are all naturally adapted to and found in those lower salinities. As a result, saying they do well or better at the lower salinty is a far cry from saying oceanic species that are not normally found in those lower salinities will do better in lower salinity.

Also FrogfishFeeders ghost shrimp are naturally found in both FW and full SW, as well as everything in between.

BTW for interesting twist, some FW species are known to run to SW and grow bigger in SW than in full fresh.

Yes, Bill. Fish are known to grow bigger in larger bodies of water (i.e. striped bass grow to over 100 pounds in the ocean) ...but I haven't seen any empirical data other than sick fish heal better in lower salinity.

"Natural Sea Water is much more saline than the internal fluids of marine fish. Because of this, they expend a considerable amount of energy to reduce the excessive salt load through the process of osmoregulation. The kidneys are not the primary site of electrolyte management in marine teleost fish (Stoskopf, 1993). Chloride cells in the gills excrete excess chloride and sodium. "œThe kidneys of marine fish do play a role in electrolyte excretion; however, there function is more important in the balance of magnesium and sulfate levels and not, as might be assumed, in sodium and chloride elimination" (Stoskopf, 1993)."

http://www.advancedaquarist.com/2007/6/fish


Thanks.

 

[Randy Holmes-Farley]

The problem with your simplistic sodium discussion is that if you make the water lower in salinity, EVERYTHING declines, and cells actively take up many things. Dropping them by a factor of 2 or 4 will make it that much harder for those to be attained.

So in my simplistic assessment, you will trade the energy needed to pump out sodium and chloride against the difficulty in attaining these other ions.

Perhaps even more importantly, some critical points might get crossed where big changes happen. For example, you make calcium carbonate skeletons soluble as salinity declines, and they will dissolve, for example.


Here's an article which details how calcium carbonate becomes undersaturated as fresh water is added to the ocean (from rivers or ice melt):

http://www.biogeosciences.net/6/2421/2009/bg-6-2421-2009.pdf

 

[billsreef]

Yes, Bill. Fish are known to grow bigger in larger bodies of water (i.e. striped bass grow to over 100 pounds in the ocean) ...but I haven't seen any empirical data other than sick fish heal better in lower salinity.

"Natural Sea Water is much more saline than the internal fluids of marine fish. Because of this, they expend a considerable amount of energy to reduce the excessive salt load through the process of osmoregulation. The kidneys are not the primary site of electrolyte management in marine teleost fish (Stoskopf, 1993). Chloride cells in the gills excrete excess chloride and sodium. "œThe kidneys of marine fish do play a role in electrolyte excretion; however, there function is more important in the balance of magnesium and sulfate levels and not, as might be assumed, in sodium and chloride elimination" (Stoskopf, 1993)."

http://www.advancedaquarist.com/2007/6/fish


Thanks.

From the same article you just quoted from,

I am not suggesting that all marine fish be kept in hyposaline conditions indefinitely.

There has also been some research showing that keeping stenohaline marine fish in hyposaline conditions long term can lead to health issues such as fatty liver. Unfortunately it's been a rather crazy and hectic day that isn't truly finished yet, so I haven't had time to look up those references.

BTW I do happen to like hyposalinity treatment for short term therapy (4 to 8 weeks) for a number of parasite issues that respond well to it.