It was an ordinary day. Looking through the scrapbooks that Carol and I have made for the past 20 plus years of our vacations we have taken. Trips to exotic sites in the Caribbean, visits to the islands in the state of Hawaii, travel to beaches in Florida and family vacations to points along the Jersey shore. All the scrapbooks are fun to view and Carol and myself love to try and remember each and every vacation we have taken since I retired from teaching in 1999. While looking at one of the trips to the New Jersey shore we noticed a few pictures of horseshoe crabs that were along the edge of the water in some of the photos. Neat animals?? that are a bit scary, but make you wonder exactly how long they have been inhabitants of the Jersey shore. Seems that the American horseshoe crab is also a common sight along the beaches of Florida. Also read that the horseshoe crab is found up and down the Atlantic coast from Maine to Mexico. They are not really crabs, but are more closely related to spiders and other arachnids than they are to crabs or lobsters. There are four species of horseshoe crabs that have been around for at least 445 million years, way longer than dinosaurs have been around. The horseshoe crabs have one species that is found in North America along the Atlantic and Gulf coasts while the other three species are found in Southeast Asia. The body structure of the horseshoe crab is just about the same today as it was years and years ago. The Horseshoe crab has a tank-like structure with a front shell called the prosoma, a back shell called the opisthosoma, and a spike-like tail called a telson.
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| The horseshoe crab |
And...the crab is totally harmless to humans. The horseshoe crab has a hard shell, 10 eyes, a pair of compound eyes on the prosoma and "photo receptors" in other areas, primarily along the tail. You should never pick up a horseshoe crab by the tail as it can harm the animal. Instead, gently pick it up by both sides using both hands. Horseshoe crabs are known to gather in large nesting groups on beaches in the mid-Atlantic states such as Delaware, New Jersey and Maryland in the spring and summer.  |
| A pair of horseshoe crabs mating. |
Their populations are largest in the spring and summer, but they can nest year-round in Florida with their peak spawning occurring in the spring and fall. When mating the smaller male hooks himself to the top of the larger female's shell by using his specialized front claws, and together they crawl to the beach. The male fertilizes the eggs as the female lays them in a nest in the sand. Horseshoe crab larvae emerge from their nests several weeks after the eggs are laid. The young and adult horseshoe crabs spend most of their time on the sandy bottoms of the inter-tidal flats or zones above the low tide mark and feed on various invertebrates. The Horseshoe Crab is an important part of the ecology of coastal communities. Their eggs are the major food source for shorebirds migrating north. The shorebirds have evolved to time migrations to coincide with peak horseshoe crab spawning activity, especially in Delaware and the Chesapeake Bay areas. Many other types of fish as well as birds feed on horseshoe crab eggs in Florida while the adult horseshoe crabs serve as prey for sea turtles, alligators and sharks. Horseshoe crab numbers are beginning to decline so the Atlantic States Marine Fisheries Commission |
| A large number of crabs gather for mating. |
developed a management plan that requires all Atlantic coastal states to identify horseshoe crab meeting beaches. The horseshoe crab that we find today isn't that much different than the horseshoe crab found millions of years ago, even with horseshoe crabs living to be only about 20 years old. When I find one along the coast line I look at it and wonder if I should touch it. Well, it seems that they don't bite or sting. They do look ferocious with the sharp, pointed tail and rough edges along their body, but they will not harm you. If you would ever try to pick one up, make sure you pick them up by holding them along either side to do so...don't pick them up by the tail. They feed on small clams, crustaceans and worms and may also eat other small animals as well as algae. They crush their food between their legs before passing it to their mouth. They also have gizzards for grinding food before it reaches their stomachs. The horseshoe crab has a blood-clotting agent known as Limulus Amebocyte Lysate (LAL) which clots in the presence of certain groups of bacteria. The FDA requires the use of LAL to test all injectable and intravenous drugs produced in the USA and the good news is that up to one-third of a horseshoe crab's blood can be removed without killing the animal. If you ever find what you think looks like a dead horseshoe crab on the beach, please pick it up gently along the sides of the shell and release it back into the sea, since they may still be alive. The horseshoe crab plays a vital role in ecosystems along the eastern coastline of the United States. They do live most of their lives unseen in the water, but emerge in droves during full and new moons during mating seasons to lay hundreds of thousands of egg to Endre this long-lasting species' existence for future generations. The horseshoe crab is one of the most experienced species on the planet. They are often called "living fossils," and have ancestors that can be traced back through the geologic record to around 445 million years ago, 200 million years before dinosaurs existed. Being that they have 10 eyes they see everything! They also have 10 legs, but are not actually crabs but arachnids as are spiders and scorpions. When they do come to shore they come in droves. The female can lay about 4,000 tiny green eggs in an evening and continue to do the same the next day until she has laid over 100,000 or more. And, even though shorebirds eat plenty of the eggs, there are still many left over to keep the species alive for many more generations. It was another extraordinary day in the life of an ordinary guy.
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