Invasive SpeciesAsian shore crab

Hemigrapsus sanguineus
FOUND by Flaming marshmallows
2015-10-20
Cape Elizabeth
ID Confirmed
Quality checked by Ocean llamas
Peer reviewed by Mrs. Moniz
Field Notes
Cold fog and a salty, seaweedy smell greeted us as we stepped off the bus at 9:10 and arrived at the beach. There was a light fall breeze and boats were rocking in the choppy harbor. We could hear the yells of students running around and the waves gently crashing on the beach. It was low tide and there was plenty of beach and tidepools; perfect for looking for the Asian Shore Crab. The rocks were slippery with algæ, and rain from earlier that morning. Wind blew our hair as we ran down the slippery rocks and onto the rock strewn beach to begin our search. The Asian Shore Crab hides in small seaweed covered tide pools with plenty of rocks to dart underneath. The feeling of the ice cold water surprised us as we reached our already wind chilled hands into the water to grab a crab. At first, we had difficulties finding the Asian Shore Crab. After looking a little longer, we found a nice big crab. We think that the difficulties we had were because the crabs were scared by the amount of people on the beach looking for their species.
Supporting Evidence
Photo of my evidence.
We think we found the Asian Shore Crab because of the fleshy bulb like structure in between each claw. The picture clearly shows the fleshy bulb, as indicated by the red arrow, in between the claw. The Asian Shore Crab is the only crab that has this in between their claws. All of the other crabs do not have anything between their claws except the Hairy Clawed Shore Crab, which has a sponge like tuft of hair in between each claw.
Photo of my evidence.
We think we found the Asian Shore Crab because the crab we found has three spines outside each eye. One of the identifying features of the Asian Shore Crab is the three spines outside each eye. We know that this is not a Green Crab because Green Crabs have five spines outside each eye. This is definitely an invasive species because it has less than six spines beside each eye. All invasive species have less than six spines. We, we know that this is the Asian Shore Crab because it has banded legs. Most crabs have legs that are just one color. On this crab you can clearly see the stripe.
Photo of my evidence.
We think we found the Asian Shore Crab because of the square shaped carapace. The carapace is the shell on the crab. One of the identifying characteristics of the Asian Shore Crab is the square shaped carapace. We know this is not the Green Crab because the Green Crab has a pentagon shaped carapace. Also we can tell this is an Asian Shore Crab because of the red dots on its claw ( the dots are shown by the blue arrows). We know this is not the Jonah crab because the Jonah crab doesn’t have any red dots on its claw.
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 43.560400 °
Longitude: 
W -70.217547 °
Observation Site Information
A photo of our study site.
Habitat: 
Coastal - Rocky intertidal
Trip Information
Name:
Kettle Cove Oct 2015
Trip date: 
Tue, 2015-10-20 07:40
Town or city: 
Cape Elizabeth
Type of investigation: 
Species Survey
Ecosystem: 
Coastal
Watershed: 
Presumpscot
Time of low tide: 

Comments

What a nice observation. Your field notes were a pleasure to read and I love how you used arrows to indicate which features of the crab you were highlighting in your written evidence.

Keep up the amazing work!