Invasive SpeciesAsian shore crab

Hemigrapsus sanguineus
Kennebunk, ME
ID Confirmed
Quality checked by mshansen
Peer reviewed by MSK_KT
Field Notes
I was happy because we were able to find many species, and also some invasive. This is not good, but now we can notify you that the invasive species are there. When I was there I heard the waves crashing, I smelt the salt from the ocean and the seaweed. I saw mostly seaweed on top, but once I got into my quadrant there were plenty of other organisms to find. I am surprised that I found so many crabs, I was not expecting this. I was also surprised that we did not find a lot of native periwinkles, I mostly saw common periwinkles. I was also surprised that we didn't find much dead man's fingers, this was something I was happy about. When going through the tide pools it was hard to walk on the seaweed, it was very slippery. Also, I came close to falling, luckily I caught my self each time.
Supporting Evidence
Photo of my evidence.
This picture clearly shows the strips on this crab, which is a characteristic of an Asian Shore Crab.
Photo of my evidence.
This shows the three points between up the side of the crab. This is another reason it may be the Asian Shore Crab.
Photo of my evidence.
This photo shows the unique square shell, and spots on the crabs claws. Two more reasons it is an Asian Shore Crab.
Species Observation: Species Looked For
Did you find it?: 
I think I found it
Scientific name:
Hemigrapsus sanguineus
Common name:
Asian shore crab
Is it alive?: 
All alive
Count of individuals: 
How big is it?: 
2 - 5 cm
Is it male or female?: 
Can't tell
Sampling method: 
Quadrat (user-placement)
Time search
Photo of our sampling method.
Place Studied
We’re sorry, JavaScript is required to view the map. If JavaScript is you may wish to upgrade to a newer browser in order to view this map.
Map this species
N 43.344150 °
W -70.486670 °
Observation Site Information
A photo of our study site.
Coastal - Rocky intertidal
Trip Information
Kennebunk Beach Blue&Green
Trip date: 
Fri, 2012-05-25 09:30
Town or city: 
Kennebunk, ME
Type of investigation: 
Species and Habitat Survey
Time of low tide: 
Fri, 2012-05-25 08:46
Habitat Observations
Species diversity: 
18 different species
Evidence of vectors: 
Paved road
Walking trail
Water temperature: 
Dissolved oxygen: 


Really interesting to see this. You seem to have found two invasive species in the same area - we spotted the Green Crab entry as well and were wondering what that means in terms of actions. Are there actions that need to be taken to protect the area?

You did a great job identifying the key characteristics of this crab.

That is a great photo depicting the squareness of the shell! Nice work.