The fiddler crab is known for its remarkable asymmetrical claws, but it is not typically referred to as a "living clock." However, there is an interesting aspect related to time in their behavior:

Fiddler crabs have daily activity cycles that are closely tied to the tidal rhythms. They are most active during low tide when they emerge from their burrows to feed and perform their characteristic claw-waving displays. The timing of these activities follows a circadian rhythm, which can be influenced by environmental factors like light and tides.

So, if we were to interpret the statement metaphorically, you could say that fiddler crabs indicate the time of day or tidal phase through their activity patterns. However, this is not a precise function like a clock but rather a natural behavioral pattern aligned with environmental cues.