A male fiddler crab with distinctive asymmetric claws, major claw much larger than the minor claw, picking up sediment from the muddy ground at Gaomei wetland preservation area, Taichung, Taiwan

fiddler crab calling marine mud flat wetland mangrove species ecosystem ocypodidae claw male sexually dimorphic shell muddy asymmetric sediment ground mouth eat gaomei marsh preservation preserve wild wildlife taichung taiwan asia nature natural habitat environment outdoors swamp beach animal water background crustacean close up fauna soil sand gelasimus borealis tidal forage