Subtidal | Tidal | Semi-terrestrial
An oddity of nature: This is a "Super" male fiddler crab with two over--sized claws.
(Great for defending a burrow but a problem when gathering food.) Courtesy: Nancy Church
More on Fiddler crabs.
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The male fiddler crab (Uca) defends his bayside burrow and attracts a mate with one over-sized claw. The smaller claw is used to pick food out of the sediments. |
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Female fiddlers have only feeding claws. Their stalked eyes help the crabs watch for predators like wading birds. To read more about wading birds and the prey they stalk in the marsh, click here.
(Below, left) A puzzling find is the shed skin of the mole crab (Hippa). In the surf zone, mole crabs filter food from the sediments with their antennae. See close-ups on the right. |
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(Above) Mole crabs are abundant in the warmer weather, right
at the shoreline. Dig for them in the wet sand, but always release them afterwards. Females are larger than males and often carry "berries" - an orange egg patch on their belly. |
Mole crabs survive by filtering microorganisms in the swash of the waves. They move into deeper water in the winter. |
| (Right) The green crab (Carcinus) is a European species that hitch-hiked to the East Coast over 100-years ago. |
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A new addition to Sandy Hook's fauna is the Japanese shore crab (Hemigrapsus), an invasive species that probably hitched-hiked here in the ballast water of ships. For more information on the shore crabs and our study of them, click here. |
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Handle all crabs carefully so that you do not get pinched and they do not detach a claw to try and escape. Pick them up from the back - and hang on tight! Return them to the same spot you collected them; especially fiddler crabs that live in a burrow. (Below, left) The detached claws of a rock crab (Cancer) and the larger Jonah crab. (Below, right) Male blue crabs have a belly patch that looks like a lighthouse and this immature female's patch is broader and triangular. |
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| (Right) A common find on the beach in the Fall is the shed of a rock crab. Crabs grow by backing out of their old shell. |
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After checking the size, species and sex of our catch, it is time to reset the trap. While waiting to pull the trap again, we scour the shoreline for scuds and sand-hoppers. (Below) |
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