Description

Habitat & Habitat Type:
Chasmagnathus convexus, commonly known as a Rainbow mud-flat crab, inhabits the intertidal zones of East Asia—particularly along coasts, estuaries, and salt marsh areas—making it a saltwater (marine/brackish) species.
It has been found in highly saline areas and is prevalent in the upper intertidal zones, including regions where riverine and marine environments meet.

Environmental Tolerance:
This crab is euryhaline, meaning it can tolerate a wide range of salinities—from brackish to near-fresh levels (approx. 4 to 52 ‰). Despite this adaptability, its natural habitat remains coastal mudflats rather than true freshwater ecosystems.