Marine/mangrove crabs?

Question

How does mangrove crabs deal withh salinity, the variance in temperature. What kind of adaptations do they have?

Answer 1

Many marine animals adapted to brackish conditions. They developed a tolerance to changes or died, and those that lived passed it on. They sense and move with tidal flux to keep comfortable levels of salinity, and cold is just a slowing of metabolism where warm will speed it up. This is so for crustaceans as well as fishes. Trout are notably fresh water, but have a natural ability to handle salinity and will frequent brackish areas, and they can be real monsters.