Horseshoe crabs are not true crabs at all. Horseshoe crabs are more closely related to arachnids (a group that includes spiders and scorpions) than to crustaceans (a group that includes true crabs, lobsters, and shrimp). Horseshoe crabs are often called "living fossils" because fossils of their ancestors date back almost 450 million years--that's 200 million years before dinosaurs existed.
Despite inhabiting the planet for so long, horseshoe crab body forms have changed very little over all of those years.
The Anatomy
The strange anatomy of the horseshoe crab is one of this animal's most notable aspects. Unfortunately, the long, thin, spike-like tail of horseshoe crabs has given this species an unfavorable reputation. Many people view horseshoe crabs as dangerous animals because they have sharp tails. In reality, horseshoe crabs are harmless. Their tails are used primarily to flip themselves upright if they are accidentally overturned.
Horseshoe crabs are known for their large nesting aggregations, or groups, on beaches. During the nesting season, principally in spring and summer, male horseshoe crabs move parallel to the shoreline on sandy flats and intercept females as they pass by. A successful male attaches himself to a female by using his specialized front claws, and together they crawl to the beach. Most of this nesting activity takes place during high tides in the three days before and after a new or full moon.
Why are horseshoe crabs important?
Horseshoe crabs are an important part of the ecology of coastal communities. During the nesting season, horseshoe crab eggs become the major food source for migrating birds. Over 50 percent of the diet of many shorebird species consists of horseshoe crab eggs. Many bird species have been observed feeding on horseshoe crab eggs. In addition, many fish species rely on horseshoe crab eggs for food.
Horseshoe crabs are extremely important to the biomedical industry because their unique, copper-based blue blood contains a substance called Limulus amebocyte lysate. The substance, which coagulates in the presence of small amounts of bacterial toxins, is used to test for sterility of medical equipment and virtually all intravenous drugs. Research on the compound eyes of horseshoe crabs has led to a better understanding of human vision. The marine life fishery collects live horseshoe crabs for resale as aquarium, research, or educational specimens, and the American eel and whelk fisheries use horseshoe crabs
Threats to horseshoe crabs and research efforts
Horseshoe crab numbers are declining throughout much of the species range. Although scientists are unsure of the exact causes of this decline, it is probably due to a variety of factors, including the degradation or decrease of habitat.
You can find horseshoe crabs here in the Mexican Caribbean. They are very neat to see when they come ashore. You truly feel like you have gone back millions of years, to watch these ancient creatures in their natural setting. Contact us today to buy a piece of paradise!
You can find horseshoe crabs here in the Mexican Caribbean. They are very neat to see when they come ashore. You truly feel like you have gone back millions of years, to watch these ancient creatures in their natural setting. Contact us today to buy a piece of paradise!
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