Invasive SpeciesGreen crab

Carcinus maenas
FOUND by crabbycrabbers
Cape Elizabeth Maine
ID Confirmed
Quality checked by Pp
Peer reviewed by Jd,cb
Field Notes
Field Notes: The trip to Crescent Beach, Cape Elizabeth, Maine, took place under an overcast sky, the water sat still with almost no ripples in sight. Seagulls could be seen, but not in the amount you'd picture, since they're associated with summer, and we are in mid-fall. You can hear the commands of teachers and the discussions of groups being contrasted by a soft scuff of rocks and squelch of seaweed. Both green crabs, and other various crabs were surprisingly easy to find- as soon as the first rock was flipped, they were seen scuttling frantically, without appearing to have any escape plan.
A sketch of our study site.
Supporting Evidence
Photo of my evidence.
A shared feature between the Vital Signs ID card and the specimen that we observed was that they both had a pentagon shaped shell. This supports the argument because this is a trait unique to the Green Crab. The Asian Shore Crab has a square-like shell with dulled corners which separates it from our species.
Photo of my evidence.
This crab that we found and studied had another characteristic that differentiates it from other crabs. It had 5 spines on the outer side of each eye, while the Asian Shore Crab has 3 spines on the outer sides of its eyes.
Photo of my evidence.
The Asian Shore Crab, a commonly mistaken crab that we found on our trip has banded legs. The crab that we found appeared to have solidly colored legs, which both clarifies that we didn't find the Asian Shore Crab and supports that we did find the green crab.
Species Observation: Species Looked For
Did you find it?: 
I think I found it
Scientific name:
Carcinus maenas
Common name:
Green crab
Sampling method: 
Just looking around
Photo of our sampling method.
Place Studied
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Map this species
N 43.563470 °
W -70.228836 °
Observation Site Information
A photo of our study site.
Coastal - Beach or dune
Trip Information
Kettle Cove (CEMS 7th Grade)
Trip date: 
Tue, 2014-10-28 09:22
Town or city: 
Cape Elizabeth Maine
Type of investigation: 
Species Survey
Time of low tide: 
Tue, 2014-10-28 08:25


Great description! I love the name crabbycrabbers!