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

Anotado por dan_johnson dan_johnson, 11 de mayo de 2018 a las 06:12 PM

Comentarios

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

Anotado por bouteloua hace mas de 4 años (Advertencia)

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

Anotado por dan_johnson hace mas de 4 años (Advertencia)

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!

Anotado por sambiology hace mas de 4 años (Advertencia)

Very nice. Good information. Thanks.

Anotado por sagamoreoh hace cerca de 4 años (Advertencia)

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

Anotado por carolr hace cerca de 4 años (Advertencia)

good info....thanks

Anotado por blueturtle hace cerca de 4 años (Advertencia)

This is great. Thanks for creating this.

Anotado por sbadams hace cerca de 4 años (Advertencia)

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

Anotado por heteromyid hace casi 4 años (Advertencia)

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

Anotado por mfeaver hace mas de 3 años (Advertencia)

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

Anotado por loarie hace mas de 3 años (Advertencia)

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

Anotado por sambiology hace mas de 3 años (Advertencia)

GREAT, thank you

Anotado por skrentnyjeff hace casi 2 años (Advertencia)

thank you

Anotado por gary-james hace más de un año (Advertencia)

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"? ;-)

Anotado por baldeagle hace 9 meses (Advertencia)

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