When you visit to an intertidal area such as the Labrador Nature Reserve Beach, you would almost certainly hear occasional snapping pops coming from the ground. These are from snapping shrimps. They live in excavated burrows lined with small stones as a sort of embankment or reinforcement to keep the surrounding sand in place.
One of the amazing things is that the snapping shrimps usually have a live-in goby fish. These two rely on each other. The goby probably relies on the shrimp for protection whereas the shrimp relies on the goby as a lookout. The goby is seen frequently at the edge or rim of the burrow and darts in and out whenever it feels threatened.
In the clip, you can see a dark banded goby coming out first before the shrimp starts housekeeping by clearing sand which has flowed into the burrows with the waves. If there is a hint of trouble, the goby darts into the burrow.
How does the snapping shrimp make the snap?
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another earlier post : sgbeachbum.blogspot.com/2008/05/beautiful-cyrene-4-red-snapping-shrimp.html