Invasive SpeciesAsian shore crab

Hemigrapsus sanguineus
NOT FOUND by Flitterfluff
ID Confirmed
Quality checked by Go science
Peer reviewed by TinyElephant
Field Notes
It was a gloomy and damp day, 9:00 am. It was wet and rainy and it wasn't too cold. There were lots of seaweed and rocks and very little sand. We found a decent amount of crabs searching through the seaweed and they were all very little. Also the rocks were very slippery, so walking to one place to another was quite difficult. We then went off and tried to find crabs by hand, there were a lot of little crabs that were hard to get hold of under rocks so the crabs were hard to catch. We only found green crabs searching through the rocks. When we pulled up the trap there was large aggressive green crabs and a disobedient rock crab. The largest of the crabs latched onto my finger and wouldn't let go, luckily I had a glove on but he still gave me a nasty wound and it was swollen. We did not find any asian shore crabs only green crabs. Not everything went according to plan but it was still a successful trip. We can hear the crash of the waves , and smell the sea and fish and the seaweed was very slippery. We were surprised that we didn’t find the asian shore crabs because quite a few groups did find the asian shore crab. A problem that we ran into was that the bucket that had the crabs kept tipping over and the crabs would get out, so the bucket had to be held at all times and it was difficult to look for crabs. Another issue was the weather, which made it difficult to move around. Also another problem we ran into was when you're looking for crabs in the seaweed, your back aches and your neck hurts over some time bending down which makes crab hunting even more difficult.
Supporting Evidence
Photo of my evidence.
This crab has five spines which means it is a green crab unlike the asian shore crab which only has three spines.
Photo of my evidence.
The crab has long, thick, legs and narrowed claws. The asian shore crab has thin, banded legs which this crab does not have.
Photo of my evidence.
The crabs in the bucket are green crabs because of it's shell.The carapace of a green crab is a pentagon shape unlike the asian shore crab which has a square shape shell.
Species Observation: Species Looked For
Did you find it?: 
I think I did not find it
Scientific name:
Hemigrapsus sanguineus
Common name:
Asian shore crab
Sampling method: 
Quadrat (user-placement)
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 43.784670 °
W -69.721217 °
Observation Site Information
A photo of our study site.
Coastal - Rocky intertidal
Trip Information
Reid State Park river
Trip date: 
Thu, 2017-10-26 09:00
Town or city: 
Type of investigation: 
Species Survey
Time of low tide: 
Thu, 2017-10-26 10:16


Great work noting the key characteristics of these crabs!