Brackish (close enough to know what you mean) is the correct term.
Crawfish, as far as I know are true freshwater arthropod and actually bull sharks can roll full fresh water for temporary but somewhat extended periods of time. While we understand how they regulate their osmotic balance from salt to fresh we don't know exactly how long they can do it.
Most theorize they go into rivers to give birth (they are live bearers ) so the pups can reign king shit till they mature up a bit and get out to sea. But there is little evidence, leaving others to think they are just curious and roll wherever the hell they want.
But they have been found way way way inland several hundred miles into freshwater rivers...one of the cooler sharks for that fact alone imo.
Anyhow...stoner bio geek out is over...I gotta turn my compost piles and get a hillbilly hot tub going so I can bathe like a baus later
https://c1.staticflickr.com/1/202/471276379_11e484b355.jpg
