Learn About Them, But Don't Eat Horseshoe
Some people eat horseshoe crab eggs and roe, since there aren't any other edible parts on it.
These creatures aren't even really crabs, let alone any type of crustacean. Although they may
look similar to a crab, they actually belong to the family of Limulidae.
This said, they are much closer to scorpions, spiders, and ticks than they are to any
crustacean. They have been around more than 250 million years and haven't really changed all that much. The
upper portion of their body is still a hard shell that looks very similar to horseshoe crabs from the past. Not
much evolution is present among these soft-bellied creatures.
Seeing as they haven't evolved much from the fossils found of previous horseshoe crabs, their diet is probably
still very similar as well. Horseshoe crabs don't have jaws, so they have to grind up their food with bristles
found on its legs and then its gizzard takes care of the rest. They eat annelid worms, pieces of fish, mollusks,
and various other benthic invertebrates. The gizzard is similar to the one found in reptiles, birds, earthworms,
and some types of fish. There are usually small rocks present within these organs that aid in the grinding of
One of the few reasons why the horseshoe crab has
been able to live so long is because it is tolerant of different variations of
salinity in the water. It can also go an entire year without eating. Having
variations in salt water is enough to limit most sea creatures, but being able
to last for a year without food isn't something that is easily pulled off by
This marine animal can even withstand extreme
water temperatures, whereas other marine life is severely disturbed by the
slightest change in water temp.
The technique of being able to regrow lost limbs,
known as regeneration, is possessed by horseshoe crabs. This is the same technique
sea stars use to grow lost arms and geckos and lizards use to grow their tails
back. Being able to regrow a missing arm will enable a horseshoe crab to continue
living as normal, instead of slowly starving to death, due to the lack of limbs.
Taking a year off from eating would definitely be plenty of time to regrow any lost
There are four different species still alive today, three of the four being found mostly in
south-east Asia. The fourth species of horseshoe crab is found in the Gulf of Mexico and along the north-west
Atlantic coast. Other names given to these species include Saucepan crab, Horsefoot crab, and Helmet crab. It was
even thought at one time that it only had one eye, so it's scientific name, Limulus, means 'askew'.
The lifespan of horseshoe crabs is very similar in all four species; they live between 20 to 40
years, aren't sexually mature until they are around 9 years of age. They may shed their shell as many as 17 times
before they even reach the age of 9 and are fully grown between the ages of 9 and 12. With each molt, the horseshoe
crab can grow as much as 25 percent larger.
The eggs of horseshoe crabs aren't attended by the parents. Instead, they are simply deposited in the sand by the
female as she drags the male along behind her to fertilize the eggs. The male hangs onto the back of the females
shell with his claws and is usually about two-thirds the size of the female. Being this much smaller, he provides
little resistance as he is dragged around the sand by the egg-depositing female. The female can deposit around
20,000 eggs in each hole she digs, which she does every few feet or so. After the crabs are finished making the
nests and laying eggs, they leave the waves to wash sand over each nest.
People often assume the tail of the horseshoe crab is some type of weapon. It is actually used to help the crab
plow through sand and muck, plus to help turn it over if it lands on its back. These marine creatures aren't
dangerous at all. They aren't able to bite, but a person might get their fingers pinched between the two separate
parts of the shell when handling them.
Since being able to eat horseshoe crab isn't an option, but they have been used as fertilizer in the early 1900s.
They were also used as poultry food supplements. Today, the medical profession uses the dark blue blood of the
horseshoe crab to test the purity of many medicines. Its shell has also been used to speed up the clotting of blood
and to create sutures that are absorbed by the human body. The making of absorbable sutures eliminates the need to
make an appointment to have the sutures removed.
So, although these marine creatures aren't viable for human consumption, they are very helpful in other ways.