It is so nice to be traveling again after a very long pandemic break! We are back at our favorite place in Truro, MA on Cape Cod. I met a female Atlantic Marsh Fiddler Crab (Uca pugnax) this morning. Watch the whole video and you will see her chowing down like the cookie monster. Yes, she is eating the mud, along with fungus, algae, microbes and decaying plant & animal matter (maritimeaquarium.org). Fiddler crab eating and burrowing helps keep the salt marsh clean and aerated. However, recent research has shown that crab burrowing may have a negative effect on climate change by releasing greenhouse gasses (carbon dioxide and methane) sequestered in the salt marsh
Another fun fact is that fiddler crabs have gills for breathing underwater, but they also have a primitive lung, which allows them to live on land in damp ground for months (http://www.edc.uri.edu/restoration/html/gallery/invert/fiddler.htm).
The male fiddler crab has one very large claw- the bigger the claw, the more attractive to the females. The males stand in front of their burrows, hold their claws like fiddles and wave them around while stamping their feet to attract females. I can see why this would be irresistible. If the female is interested, she will stare at the male, the male runs toward her, then back to his burrow several times, inviting her to join him. If she is interested, she follows him into the burrow, he blocks the door to the burrow and they mate (https://www.chesapeakebay.net/discover/field-guide/entry/fiddler_crabs).
The natural world is fascinating. I’ll report back with any other wonders we run across here, natural or otherwise.
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