How to photograph crayfish for iNaturalist

How to photograph crayfish for inaturalist

In order for crayfish to be adequately identified, it is helpful to provide
a variety of views of the crayfish. Dorsal and lateral views should be
always provided:

In the dorsal view, make sure both the areola and rostrum are
visible:

Lateral view:

Of utmost importance for many species are photos of the gonopod (for
males) or annulus ventralis (for females).

The following image shows the ventral view of an adult male crayfish.
The gonopods are its reproductive organs. They are normally tucked
between the walking legs.

It will often be necessary to pry one into
view with a toothpick or probe. The most useful views are from a
lateral or mesial aspect.

Try to get a closeup view clearly showing the features at the tip:

The following is an image of the ventral side of a female. A closeup
photo of annulus ventralis is very helpful (small round feature between
the last two pairs of walking legs).



Try to get a clear closeup of the annulus ventralis and surrounding area
as follows.

Additional views that may be helpful for identification include:

The chela (claw)

Any hooks present in adult males

The tail fan

Posted by dan_johnson dan_johnson, May 11, 2018 18:12

Comments

Added this to the "more info" section on the right side of the taxon page>About tab!
https://www.inaturalist.org/taxa/47783-Astacoidea

Posted by bouteloua about 4 years ago (Flag)

Ah, good idea! Didn't think about that.

Posted by dan_johnson about 4 years ago (Flag)

Excellent journal entry, Dan. I’ve bookmarked this to copy and paste on observations that need some assistance for their crayfish observations! Thanks for putting this together!

Posted by sambiology almost 4 years ago (Flag)

Very nice. Good information. Thanks.

Posted by sagamoreoh almost 4 years ago (Flag)

Thank you for the excellent education on identification of crayfish. Carol R.

Posted by carolr almost 4 years ago (Flag)

good info....thanks

Posted by blueturtle almost 4 years ago (Flag)

This is great. Thanks for creating this.

Posted by sbadams over 3 years ago (Flag)

Excellent! I've been meaning to create something like this as it is very useful.

Posted by heteromyid over 3 years ago (Flag)

Hope to be able to use this excellent guide when I come across another crayfish. Thanks.

Posted by mfeaver about 3 years ago (Flag)

excellent post Dan. I wish there were more than 2 easy to identify species in CA so I could start observing crayfish this way - time for a field trip to the southeast

Posted by loarie almost 3 years ago (Flag)

@loarie -- you're welcome to Texas ANYTIME!!! :)

Posted by sambiology almost 3 years ago (Flag)

GREAT, thank you

Posted by skrentnyjeff over 1 year ago (Flag)

thank you

Posted by gary-james about 1 year ago (Flag)

Great information, @dan_johnson. You seem to have a way of getting the crawfish to hold still for photos of the gonopod or annulus ventralis. Is it called "cooking"? ;-)

Posted by baldeagle 5 months ago (Flag)

Add a Comment

Sign In or Sign Up to add comments