How do 'gator gar survive saltwater?

[Betta132]

This summer, down in Galveston, I saw an alligator gar swim by a boat ramp. It was easily four feet long, pure black, and sporting scars on its head like it'd had a run-in with a boat propeller. Also, there were a few little one-inch pilotfish trailing after it. This was pure saltwater, nowhere near a river, but the gar didn't seem to care.
I also talked to a few fishermen who'd caught gar off a nearby pier- big ones. Apparently blue crabs are good gar bait.
So how do they do that without dying of salt absorption? Are alligator gar just really good at removing excess materials in general so they can live in particularly dirty water like you get in swamps?

 

[jpcampbell123]

all gars enter salt water and brackish water enviroments buts its only the gators that will even spawn in salt water.

 

[dmopar74]

Well hot damn! Learn something new every day

 

[moe214]

I never knew this.. Or heard of it for that matter. I'd like to hear how they do this as well, anatomically what allows them to do this?

 

[Thekid]

I never knew this.. Or heard of it for that matter. I'd like to hear how they do this as well, anatomically what allows them to do this?

Osmotic regulation.

 

[moe214]

Osmotic regulation.

Thanks I'll look into it

 

[davenmandy]

Very cool

 

[HybridHerp]

...so what you're saying is that an alligator gar can theoretically be kept as a fully salt water fish? or is it more brackish? I wonder what the maximum salinity then can handle is for a long period of time....
if they can do full sea-water I'ma make an alligator gar reef because why not lol (no, I'd never do that, I'd have an easier time keeping one in a strictly freshwater system)