Brandon Slavinski | Multimedia Producer

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Wildlife Feature | Southern California Crabs

Don’t worry! Contrary to popular belief, I haven’t “lost it” or “gone crazy” (yet). Just another fun & creative passion project to dive into - and this time, it’s ALL about crabs! In a constant pursuit of my own interests in wildlife videography, photography, and information I’ve created treats in the form of stylistic imagery and highly detailed informative videos for all those interested.

In this blog you’ll see some crabs I’ve encountered within a year’s span - mostly in SoCal. With all that said, let’s get started with some generic crab facts - scroll down for video & photos!

Generic Crab Facts

  • There are more than 4,500 species of crabs.

  • Crabs are omnivores; eating both meat & plants.

  • Female pregnancy only last one or two weeks - then they lay between 1,000 to 2,000 eggs!

  • Groups of crabs living together are known as “casts.”

  • The average lifespan of a crab is 3 to 4 years.


The Fiddler Crab

There May be around 100 species of Fiddler Crab. Males have the big claw, known as a chela; while females have two normal sized claws. As for habitat they prefer mud flats, lagoons and swamps. 

The male’s claw is used in battle of ritualised combat of courtship over a female and signal their intentions between other crabs. The movement of the smaller claw from ground to mouth during feeding explains the crabs' common name; because it seems as if the animal were playing the larger claw like a “fiddle”.

Females will choose their mate based on claw size and also the quality of their waving display.

Like all crabs, fiddler crabs shed their shells as they grow. If they’ve lost legs or claws during their present growth cycle, a new one will come in when they molt. Craziest fact - If the large fiddle claw is lost, males will develop one on the opposite side after their next molt. Newly molted crabs tend to be very vulnerable because of their soft shells. They are reclusive and hide until the new shell hardens.


The Striped Shore Crab

The Striped Shore Crab AKA Lined Shore Crab AKA Pachygrapsus crassipes can be found all over Southern California’s rocky shorelines. They present beautiful colors of green and brown stripes on their shell, red claws, and a somewhat purple underbelly.

They’ll spend half it’s time on land, but will purposely submerge to wet its gills and can stay alive on land for up to 70 hours.

They’ll mate once, maybe twice a year. When the eggs are fertilized, they are held under the belly of the female. The crab eggs hatch into zoea larva, which turns into megalopae larva (the size is less than a centimeter), and then into crabs.

Pachygrapsus crassipes is omnivorous, which means it eats both plants and animals. The main diet consists of specific red and green algaes and brown seaweed. However, Pachygrapsus crassipes also eats diatoms, worms, muscles, and small dead fish, limpets, snails, hermit crabs, and isopods. Pachygrapsus crassipes can also become cannibalistic and eat each other (usually this occurs when they still have their soft-shell after molting)!


The Hermit Crab

The hermit crab is a decapod — toting five pairs of legs, which includes a pair of claws. Defense and food shredding as well as eating are the primary uses of the claws. The second and third pairs of legs help the crab walk, and the last two pairs hold the hermit crab in its shell.

There are over 800 different species of hermit crab. They’re also oddly named because they’re more closely related to certain kinds of lobsters than a crab. This is due to their bodies - which are a hard exoskeleton on the front with a soft tail on the back.

Hermit crabs have been used as pets and found in tourist shops but this is not a good practice as they don’t breed well in captivity. When the hermit crab dies, it releases pheromones signaling other crabs that there may be a shell available which then lures other crabs to a death trap.