Invasive SpeciesGreen crab

Carcinus maenas
FOUND by Algae6
2011-09-21
Biddeford
ID Confirmed
Quality checked by Whelk6
Peer reviewed by
Field Notes
We found a lot of crabs that like to grab our skin with their very pointy claws that are not very helpful when we are trying to catch him. He is slippery so it was hard to hold him in place while somebody took a picture of him and his details on his shell. We see rocks with algae and bacteria covering them. We smelled the ocean and seaweed in the air. I am surprised by how many crabs we found. We had problems because we kept falling in the water.
Supporting Evidence
Photo of my evidence.
We knew that this was a green crab because of the five spines on its carapace.
Photo of my evidence.
We also knew it was a green crab because it was 6 1/2 cm and it can grow to 10cm wide.
Photo of my evidence.
We also saw that the crab had a pentagon shaped carapace.
Species Observation: Species Looked For
Did you find it?: 
I think I found it
Scientific name:
Carcinus maenas
Common name:
Green crab
Is it alive?: 
All alive
Count of individuals: 
1-10
Coverage: 
Reproduction: 
How big is it?: 
5 - 10 cm
Is it male or female?: 
Male
Sampling method: 
Quadrat (user-placement)
Photo of our sampling method.
Place Studied
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Map this species
Latitude: 
N 43.442700 °
Longitude: 
W -70.339430 °
Observation Site Information
A photo of our study site.
Habitat: 
Coastal - Rocky intertidal
Trip Information
Name:
Biddeford Pool: Fortunes Rocks
Trip date: 
Wed, 2011-09-21 09:10
Town or city: 
Biddeford
Type of investigation: 
Species and Habitat Survey
Ecosystem: 
Coastal
Watershed: 
Saco
Time of low tide: 
Wed, 2011-09-21 23:56
Habitat Observations
Species diversity: 
13 different species
Evidence of vectors: 
Paved road
People
Recent disturbance
Water temperature: 
18.4°C
pH: 
8.4
Dissolved oxygen: 
Salinity: 
34.0ppt

Comments

That's great that you noticed the pentagon shaped shell and 5 spines. These are very reliable ways to identify these crabs.