Do isopods live in the ocean?

Yes. There are 45,000 different types of marine isopods. Isopods are crustaceans and have a body divided into three parts: head, thorax and abdomen. Actually, isopods are the most diverse of all the types of crustaceans and are unique because they are the most widely distrubed crustacean out there! When in doubt, call it an isopod…

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What lives in the spooky burrows on the beach?

The answer is appropriate for this time of year … those quarter-sized holes are the home the ghost crabs or fiddler crabs. Ghost crabs emerge to scavenger upon anything they can get including crabs or clams, bugs or insects, plants or dead stuff (detritus). The burrows are personal territories (i.e., not colonies like on Meerkat Manor). If one male tries to challenge another for his home what occurs is an interesting ritualistic “dance.” There is rarely actual contact and the better “dancer” wins. If you’re tanning on a beach blanket and hear tapping or bubbling noises under the sand, that’s the ghost crab either using their claws for digging or sounds from their gills as they breath. The burrows can be up to three feet deep.

ghostCrab

F1.mediumTop – Ghost crab burrow image (c) aquaessence.com, bottom – fiddler crab burrow image (c) jeb.biologists.org

Are spider crabs harmful?

Great question as Halloween approaches!

Common spider crabs, or sometimes called mud crabs, are harmless. In fact, their shells are covered with fine short hairs. When you (if you) attempt to pick one up they would actually feel as though their body was covered in felt.

The short little hairs are really what helps the spider crab survive. They help attach pieces of seaweed or other algae species, sponges or barnacles which aid in its main defense mechanism: camouflage.

These common spider crabs are found along the Atlantic coast from Nova Scotia to the Gulf of Mexico.

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What are the nubby little things on pilings near the beach?

Most likely, acorn barnacles.


Let me guess, they look like tiny volcanoes? And they hurt if you rub up against them?barnacles1
That is the outer shell made of calcium. They put this protective layer up when they are not under water.
When it is hide tide the acorn barnacle opens up the volcanoes structure and extends tiny little legs (cirri) all about to gather food circulating in the ocean water.
If you have digested this correctly, you now know the acorn barnacle finds a suitable spot once it is “an adult” and stays there for THE REST OF THEIR LIFE. gulp.

Image (c) uksafari.com.

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How do you know the difference between a male and female blue crab?

You must be brave enough to pinch the body of the blue crab from behind and lift it upside down (It hurts a lot if they pinch you!).

Male blue crabs have a distinct shape like a pencil – or the Washington Monument – in the center of their bellies. Female blue crabs, on the other hand, have a shape like the Capitol.

http://treadoutdoors.blogspot.com/2012/10/my-husband-gave-me-crabs.html

http://treadoutdoors.blogspot.com/2012/10/my-husband-gave-me-crabs.html

 

 

What are those sand flea thingees and why do they follow me home?

I have two answers for you here – Mole Crabs or Sand Hoppers.

Mole Crabs:

Unfortunately, not all crabs are as interesting in appearance or function as the great Atlantic Horseshoe Crab, but the mole crab has some merit.

Mole Crabs, or one type of sand fleas thingees, are properly referred to as Emerita analoga. A pretty dignified, but boring sounding Latin name – rather appropriate for the critters too.

Here is why:

  • They look like tiny lobsters, but are more closely linked to hermit crabs.
  • At low tide they are quite the efficient tunnelers and use their back legs to dig down to six inches and wait for the next high tide.

Sand Hoppers:

These little guys truly are harmless. Sand hoppers, or the other type of sand flea thingees, are properly referred to as Orchestia. They are most often found in clumps of rotting seaweed – which they eat. They resemble small shrimp and are about a half an inch long and “hop” by using their tails and last three sets of legs.

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