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

Publicado el mayo 11, 2018 06:12 TARDE por dan_johnson dan_johnson

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

Publicado por bouteloua hace casi 6 años

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

Publicado por dan_johnson hace casi 6 años

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!

Publicado por sambiology hace casi 6 años

Very nice. Good information. Thanks.

Publicado por sagamoreoh hace más de 5 años

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

Publicado por carolr hace más de 5 años

good info....thanks

Publicado por blueturtle hace más de 5 años

This is great. Thanks for creating this.

Publicado por sbadams hace más de 5 años

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

Publicado por heteromyid hace más de 5 años

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

Publicado por mfeaver hace alrededor de 5 años

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

Publicado por loarie hace casi 5 años

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

Publicado por sambiology hace casi 5 años

GREAT, thank you

Publicado por skrentnyjeff hace más de 3 años

thank you

Publicado por gary-james hace alrededor de 3 años

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"? ;-)

Publicado por baldeagle hace más de 2 años

I'll keep this in mind!

Publicado por that_bug_guy hace 8 meses

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