By Alice Mary Herden on August 15, 2020 ( Leave a comment )

Fiddler Crabs

Have you ever walked to the water’s edge of marsh habitat and seen these little crabs by the hundreds scurrying sideways? Well, let me welcome you to the fiddler crab community, where every crab has a burrow.

In Florida, there are three common fiddler crabs- the sand fiddler (Uca pugilator), the mud fiddler (Uca pugnax), and the red-jointed or brackish water fiddler (Uca minax).

Reaching around 2 inches in length, these fiddler crabs vary in color tones like tan, turquoise, black, yellow, or orange. But that’s not what is so distinguished about these crabs. It’s the males who give everyone the double-take by swaying around that huge claw!

Upon observation, you notice that the male’s dominant claw is either the left or the right, and many biologists spent a lot of time researching to answer why that one claw is so huge. One logical reason is that it’s their fighting claw.

But hold on here, let’s explore this with some creativity- like a photo/video concept.

We have Maximus Crabluius, a four-time gram weight champion weighing at 8.0 grams in the red corner. In the blue corner Styfortomius Baziern from the upper east burrows weighing in at 7.5 grams. For up to thirty minutes (biologist stated in a document during their observation), these two battled it out with various pushing and grappling formations. The winner, well, most likely Maximus.

Right-clawed fiddlers dominate the mud banks, and when it’s time, whenever that time is, he could very well seek out any opposite-clawed opponents. Why do you ask? For competitive fighting tactics. Kind of like getting the upper hand, I mean claw.

Like in human boxing, most right-handed boxers will compete against a left-hander. (Believed to give the fighter a strategic advantage because of the tactical and cognitive difficulties of coping with an opponent who moves in a mirror-reverse of the norm- Southpaw stance – Wikipedia)

Upon scientific research, left-clawed fiddler crabs may have the lesser physical strength and not necessarily want to fight. But if they do, willingly or not, they are most likely to lose against the right-clawed opponents.

Research suggests that left-clawed fiddlers more or less will use an easier approach to attract the gal that he’s interested in by ‘sneaking’ around. Kind of like… I’ll just go over here and dazzle these lovely ladies while you right-clawed dudes, ya know, do your thing.

-It would be neat to set up a camera and record while all this as it’s happening and maybe even add some voiceovers for entertaining purposes. Yep, I know I got your creative minds working now!-

Back to fiddler crabs, there are quite a few documents of research about these crabs. And I could be reading for months. So, to save time, I’ll leave some interesting links at the end of this article.

Fiddler crabs live on intertidal mudflats, and every crab has its very own burrow, and their life span is topping at two years. They are an important food source for many shorebirds as well as fish and other wildlife.

Their life cycle is pretty amazing, and this is where you may put a microscope on your ‘need to get’ wishlist.

The female carries thousands of eggs under her abdomen. When it’s time for the eggs to detach, she will scurry sideways to the water, and her eggs will hatch into free-swimming larvae called zoea (Google that). The next stage is the megalopa and will continue its journey by changing all aspects of its entire body until it reaches the sand to complete its life cycle.

The life cycle for these fiddler crabs is truly remarkable. They are very fun to observe as well as to photograph. One tip when photographing fiddler crabs is patience. They may scurry away from any ground vibration and overcast shadows.

Here are some scientific research and other links for those that really want to burrow down into learning more about Fiddler crabs:

http://www.rosenberglab.net/Pubs/JCrustBiol2001v21p839.pdf

http://richard.eriophora.com.au/pubs/pdf/HowHemmiZeilPeters-07.pdf

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2279209/

https://animaldiversity.org/site/accounts/information/Uca_pugilator.html

http://www.tbep.org/fc/Fiddler_Crab–9.html

https://myfwc.com/wildlifehabitats/profiles/invertebrates/fiddler-crab/