Native SpeciesCommon crayfish

Cambarus bartonii
FOUND by 71sj1111
Waterboro, ME
ID Questioned
Quality checked by pparent
Peer reviewed by 71am15
Field Notes
Field Notes Today I went to an ecosystem were I can get crayfish. At first I didn’t think I would get any because it looked like the dam had a very strong current. But I tried anyway. But the thing is... it wasn’t as easy as you think. I had to climb rocks, and try not to slip at the same time, the rocks there were very slippery. When I went there it’s not like there was a path of flat rocks that you could walk on, they were all bumpy. Getting to the spot were I go to catch the crayfish was kind of hard. But when I did get there, I was searching for at least 10-15 minutes before I saw my first one. But catching crayfish is kind of hard. You have to learn how to catch them, you can’t just get a net, look in the water and catch one... It’s a lot more than just that. First I had to get to were there are some shallow rocks, and were the water isn’t flowing to fast, because if the water was flowing to fast the crayfish would go with the current. Then, I had to search for them, and searching isn’t that easy either because crayfish like to hide under rock, especially now because their molting, which means there shedding there skin to grow a new one. So I had to pick up rock and actually get in the water. Because one time the rock was so heavy that I actually fell into the water! Now the habitat part, I had found the crayfish in some cobblestone, he was actually hiding under the cobble stone when I found it. This crayfish that I found was about 3 in. big. Also this crayfish was kind of a dark-brown. I found him in water that was about 3 1/2 inches tall. The water was about 62º. And when I found him he was kind of grouped up with more crayfish. There was a community of about 2-3 crayfish. This crayfish has claws that are less than a half and inch big. Also the crayfish was kind of hard to catch because he kept on going under other rocks every time I picked up a rock. Some predators of crayfish would probably be snapping turtles or fish. This crayfish might have some competition because there are many fish in this dam, I have seen many snapping turtles too! I think that crayfish are carnivores because when I went to go get crayfish I caught two and when I went to school one was dead because the other one had eaten it... :-(
Supporting Evidence
Photo of my evidence.
I think this is common crayfish because common crayfish have the same claws like lobster except theirs are much smaller.
Photo of my evidence.
I also think this is common crayfish because common crayfish has a shell that protects them when they go under rocks in case the rock falls on them, their shell will keep them from getting crushed.
Photo of my evidence.
I also think this is common crayfish because common crayfish have tiny legs that are on the bottom of them so when they are fighting they can stand on their smaller legs and fight with there claws.
Species Observation: Species Looked For
Did you find it?: 
I think I found it
Scientific name:
Cambarus bartonii
Common name:
Common crayfish
Count of individuals: 
Eggs (animals)
How big is it?: 
5 - 10 cm
Is it male or female?: 
Sampling method: 
Photo of our sampling method.
Place Studied
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Map this species
N 43.665306 °
W -70.722172 °
Observation Site Information
A photo of our study site.
Freshwater - In a stream or river
Trip Information
Trip date: 
Thu, 2012-05-03 16:06
Town or city: 
Waterboro, ME
Type of investigation: 
Species and Habitat Survey
Saco River
MIDAS Code: 
Habitat Observations
Species diversity: 
1 different species
Evidence of vectors: 
river, stream, current
Water temperature: 
Dissolved oxygen: 


This could be a young spiny cheek crayfish based on the spines on the cheek. (great photos!) A physical specimen of a male is needed for a positive ID. Your specimen is a male - see the gonopods lying between the last few walking legs?

It is interesting that one of your crayfish ate its partner. Our crayfish did the same thing. When you found the dead crayfish what parts had the other one eaten? How do you think it was killed?

When I found the other crayfish dead, it was missing his claws and all of his limbs... I also think it got killed because I had found two crayfish and one of the crayfish were fairly larger than the other one so it probably had more control over the smaller one.

Wow! This is a tiny one. I appreciate your photo with the ruler - it looks giant in your other photos! Nice fieldwork skills to see this little one and pull it from the water.

Keep looking for crayfish this summer and posting where you find them.

I would have loved to see a sketch too

I liked your evidence and how much effort you put into catching the crawfish I kniw it's difficult because I've done it before.