Invasive SpeciesAsian shore crab

Hemigrapsus sanguineus
FOUND by seventoes
2014-10-28
Cape Elizabeth Maine
ID Confirmed
Quality checked by HV
Peer reviewed by Pp
Field Notes
Today is late October and it is cold, cloudy and windy. It is about 62°F and the tide is semi-low. We can see rocks and tide pools with lots of seaweed, perfect places to find crabs. The beach air smells of salt and washed up, rotting seaweed. We were suprised that we found the Asian Shore Crab very quickly. We only had to look under one rock to find two.
A sketch of our study site.
Supporting Evidence
Photo of my evidence.
We think we did find the Asian Shore Crab because it had white bands around its legs. The Asian Shore Crab was a greenish brown color and had small dots on its front claws. I know that the crab was not the Green Crab because the Green Crab has plain legs and claws. The Vital Signs ID sheet said that the Green Crab has thin sharp legs that are green, brown, or red.
Photo of my evidence.
The Asian Shore Crab has 3 ridges to the side of its eye. According to the Vital Signs Identification Sheet, the only other crab that has three ridges is the Hairy Claw Shore Crab. You can tell the two apart by their claws. The Hairy Claw Crab has a sponge like tuft of hair near their pinchers, and the Asian Shore has spots instead. It is very unlikely that you will find a Hairy Claw Shore Crab in Maine because they inhabit the western side of the U.S. like Oregon and Washington.
Photo of my evidence.
We think we found the Asian Shore crab because its shell was about three centimeters wide and the Vital Signs coastal ID card said their shell can get up to four centimeters wide. The shell has a box-like shape with rounded edges which is different then other competing native or invasive crabs which have a circular shell or a pentagon shaped shell.
Species Observation: Species Looked For
Did you find it?: 
I think I found it
Scientific name:
Hemigrapsus sanguineus
Common name:
Asian shore crab
Sampling method: 
Just looking around
Photo of our sampling method.
Place Studied
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Map this species
Latitude: 
N 43.563272 °
Longitude: 
W -70.219553 °
Observation Site Information
A photo of our study site.
Habitat: 
Coastal - Beach or dune
Trip Information
Name:
Kettle Cove (CEMS 7th Grade)
Trip date: 
Tue, 2014-10-28 09:22
Town or city: 
Cape Elizabeth Maine
Type of investigation: 
Species Survey
Ecosystem: 
Coastal
Watershed: 
Presumpscot
Time of low tide: 
Tue, 2014-10-28 08:25

Comments

Wow - nice detailed notes. I really like the photo with the yellow oval around the carapace spines!