Invasive SpeciesAsian shore crab

Hemigrapsus sanguineus
FOUND by SuperSaucyShore
2017-10-24
Cape Elizabeth
Not Yet Reviewed by Expert
Quality checked by Mrs. Fanning
Peer reviewed by Greasy Pugasoras
Field Notes
When we stepped off the buses at 9:00 AM on October 24th 2017, we were met by a cold and strong coastal wind, an almost entirely cloudy sky and the familiar smell of salty sea water from the crashing Kettle Cove Beach waves. The tide was just beginning to come in with lots of exposed tide pools, perfect for crabbing. We wanted to collect information on the Asian Shore Crab to see if their population is still growing. We wanted to put more information on Maine’s newest Invasive Species into the Vital Signs database. To find the Asian Shore Crab, we knew we had to look under seaweed covered rocks close to the ocean.
Supporting Evidence
Photo of my evidence.
We think we found the Asian Shore Crab because it has a square-like carapace (shell). This is a common feature of Asian Shore Crabs that sets them apart from Green Crabs because Green Crabs have pentagon shaped carapaces. Another characteristic of Asian Shore Crabs is their brown and white banded legs.
Photo of my evidence.
We think we found the Asian Shore Crab because of the three spines protruding from the side the carapace. Asian Shore Crabs always have three spines no matter what. This is the single most important characteristic of any crab that makes them different from others. We know that it can’t be the Green Crab because Green Crabs always have five spines.
Photo of my evidence.
We think we found the Asian Shore Crab because of the distinctive spots on the claws. This crab did not have a common characteristic of the Asian Shore Crab which is the fleshy bulb in between the pincers. According to the U.S. Geological Survey website for Nonindigenous Aquatic Species, only Male Asian Shore Crabs have the fleshy bulb. Our Asian Shore Crab was female.
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 43.561176 °
Longitude: 
W -70.218948 °
Observation Site Information
A photo of our study site.
Habitat: 
Coastal - Rocky intertidal
Trip Information
Name:
Kettle Cove
Trip date: 
Tue, 2017-10-24 09:30
Town or city: 
Cape Elizabeth
Type of investigation: 
Species Survey
Ecosystem: 
Coastal
Watershed: 
Presumpscot
Time of low tide: 
Tue, 2017-10-24 08:26

Comments

Great evidence photos - very in focus!