Limulus polyphemus “The creature that crawled out of the past!” Horseshoe Crab Limulus polyphemus “The creature that crawled out of the past!”

Horseshoe Crab Distribution most popular area for the horseshoe crabs is in the Delaware Bay

Spawning Habitat Shorebirds feasting on horseshoe crab eggs Eggs need - porous, well-oxygenated sediments In 1995, B95 was tagged and estimated to be close to 20 years old. Dubbed "Moonbird" because the total number of miles this red knot has traveled during its lifetime is equivalent of the distance to the moon and halfway back. Shorebirds feasting on horseshoe crab eggs

Nursery Habitat Within bays and coves, next to sandy beaches The water is shallow, food is sufficient, and has their preferred salinity of the water around 5 ppt (parts per thousand). 

FACT Among the world’s oldest creatures How long have they been on this planet? 540 million years ago to the present Before human civilization Before the dinosaurs Before flowering plants During the era in our planet's history when visible life first appeared (one celled organisms) Toward the end of the Cenozoic Era, beginning with the Holocene (11,000 BC to the Present), we look specifically at the evolution and development of the Delaware Bay.

FACT 4 known species in the world Only 1 species found along the Delaware coastline (range from Maine to the Yucatan Peninsula) LARGEST concentration in the world is found in the Delaware Bay It is not really a crab! What is the horseshoe crab closely related too? Spiders and scorpions (arthropod, arachnids) How many pairs of claws does a horseshoe crab have? 5 pairs True crabs have ONLY one pair of claws They also lack antennae and mandibles like true crabs Like a spider, horsecrabs have 2 claws located in front of their mouth

FACT When is the BEST time to see horseshoe crabs? Last spring (May) when the come ashore to spawn Which is larger in size, the male or the female? FEMALE She deposits on an average 4,000 eggs in nests along the shore line Horseshoe eggs serve a great food source for which animals? MIGRATING shore birds Which shore bird’s life depends on the horseshoe crab eggs?

Red Knot Star of the Show!! A MOST amazing athlete It can out-eat, out-race, out-distance, and out-perform any one of YOU or any human at every turn!

Rufa Red Knot Calidris canutus rufa one of the longest distance migrants in the animal kingdom. Wingspan of 20 inches, 9 inch length (size of robin) This bird flies more than 18,000 miles each year between breeding grounds and wintering grounds In just a few days, the birds nearly doubles their weight with eggs December 2014, the U.S. Fish and Wildlife Service announced federal protection for the rufa red knot Designating it as threatened under the Endangered Species Act.

This tiny tracking device fitted to the red knot contained a clock, a microprocessor, and a battery

Horseshoe Crab Taxonomy Kingdom: Animalia Phylum: Arthropoda — joint-legged animals Subphylum: Cheilcerata — animals with no jaws Class: Merostomata — mouth surrounded by legs Subclass: Xiphosura — from the Greek Xiphos meaning sword and ura meaning tail Order: Xiphosurida — sword-tailed animals Family: Limulidae — one living member, Limulus Genus: Limulus — from the Latin, meaning somewhat oblique, odd, or askew and referring to the sideways placement of the compound eyes Species: polyphemus — from the Greek, meaning one-eyed giant and referring to the simple eyes on the front of the shell

Anatomy What is the top view of the shell of the horseshoe crab called? Dorsal What name was the horseshoe crab first called? Horse foot What the bottom view of the shell called? Ventral

Male Horseshoe Crab

horseshoe crab in the process of molting

Male vs Female

horseshoe crabs shell

one of the compound eyes of a horseshoe crab

the hinge that joins the cephalothorax and opisthosoma.

a horseshoe crabs anus

Super close-up photo of a horseshoe crabs chelicerae

how a horseshoe crab can curl up for protection

open gills of a horseshoe crab

the book gills and flap cover genitalia of a horseshoe crab

male horseshoe crab upside down

movable spines of a horseshoe crab

the horseshoe crabs chelicerai (front pincers)

underside of a male horseshoe crab with barnacles

the mouth of a horseshoe crab

male horseshoe crabs mouth

front claws of a male horseshoe crab

male horseshoe crabs front leg

male horseshoe crabs pusher leg

male horseshoe crab close-up

a female horseshoe crabs underside

a female horseshoe crab flaps covering genitalia

Horseshoe crabs serve an important role in the bay ecosystem How?

They feed at night, primarily on mollusks, crustaceans and worms on the ocean floor Their eggs are an important food source for at least 11 species of migratory shore birds Including the red knot Sea turtles also eat the eggs and larvae. Eggs are important for the shoreline ecosystem Adult horseshoe crabs are preyed upon by sharks, sea turtles, gulls Humans for use them as bait or fertilizer

How Horseshoe Crab Blood Saves Millions Of Lives Crash: A Tale of Two Species (PBS) https://www.youtube.com/watch?v=e8KlAmtIu1E (3:16)

Frederick Bang In the 1950’s discovered that the blood of horseshoe crabs contained a clotting agent that when it comes in contact with certain types of bacteria it clots the blood and forms a gel that surrounds the bacteria. This allows for the bodies antibodies to take care of the bacteria. Bang and an associate created Limulus amoebocyte lysate or LAL which is now used to test for certain types of bacteria. Horseshoe crabs are captured and after they are inspected, blood is carefully bled. The procedure does not usually harm the horseshoe crabs and death rates are very low. One quart of LAL sells for $15,000.

How Horseshoe Crab Blood Works Blood has remarkable antibacterial properties Crab blood is bright blue It is copper-based hemocyanin to transport oxygen where vertebrates (including humans) use iron in hemoglobin Many invertebrates have amebocytes instead of white blood cells to fight infection Horseshoe crab amebocytes coagulate around as little as one part in a trillion of bacterial contamination Unfortunately, overharvesting in North America has led to a decline in crab populations

How are horseshoe crabs useful to people? Food source for the Native Americans Shell used to scoop water Tails used as tips for fishing spears Fertilizer for crops

What is chitin? Ki – tin) A substance that makes up the horseshoe crab shell How is it used? Surgical sutures and bandages that promote healing How is Lysate (li-sate), a chemical found in horseshoe crab blood useful to human? It is used to diagnose contaminants in prescription drugs

Make your Horseshoe Crab Model When done, answer the puzzle questions

Horseshoe Crab Model Can you locate the compound eyes? Is your crab model a male or a female? Female Explain how you can tell

Quiz Time

Where (and when) do horseshoe crabs evolve? The evolution of the horseshoe crab extends back far before the dawn of human civilization, before the dinosaurs, before flowering plants... back to the era in our planet's history when visible life first appeared. from the Paleozoic Era and provides an overview of the changes to our planet's geology, climate, flora and fauna from 540 million years ago to the present. Toward the end of the Cenozoic Era, beginning with the Holocene (11,000 BC to the Present), we look specifically at the evolution and development of the Delaware Bay.

Horseshoe Crab Taxonomy Kingdom: Animalia Phylum: Arthropoda — joint-legged animals Subphylum: Cheilcerata — animals with no jaws Class: Merostomata — mouth surrounded by legs Subclass: Xiphosura — from the Greek Xiphos meaning sword and ura meaning tail Order: Xiphosurida — sword-tailed animals Family: Limulidae — one living member, Limulus Genus: Limulus — from the Latin, meaning somewhat oblique, odd, or askew and referring to the sideways placement of the compound eyes Species: polyphemus — from the Greek, meaning one-eyed giant and referring to the simple eyes on the front of the shell

Male Horseshoe Crab

horseshoe crab in the process of molting

The Horseshoe Crab (also known as the King Crab) a hard-shelled invertebrate that lives in warm, shallow coastal waters on the sea floor. It is not really a crab; it is more closely related to arachnids (spiders and scorpions). first appeared about 500 million years ago (during the Ordovician Period), and has changed very little since. There are four species of Horseshoe Crabs alive today; they live off the coasts of India, Japan, Indonesia, the eastern USA, and the Gulf of Mexico.

Diet: eats sea worms and mollusks (like young clams) Diet: eats sea worms and mollusks (like young clams). They find their prey while walking along the sea bed; they are predominantly nocturnal (most active at night). Reproduction: hatch from eggs that the female lays. She lays roughly 20,000 small, green eggs in holes that she digs in the sand on the beach.

Anatomy a hard outer shell (an exoskeleton), 5 pairs of jointed legs and a pair of pincers. The Horseshoe Crab is up to 2 ft (60 cm) long and weighs up to 10 pounds (4.5 kg); it molts its skin many times as it grows. The male is two-thirds the size of the female. The long tail is not a weapon; it is used as a rudder (for steering) and for righting itself when it is flipped upside down. The Horseshoe Crab has light blue, copper-based blood. It breathes using book gills, thin plates located on the abdomen.

have 5 sets of leg like appendages that are used for mobility and to direct food into it’s mouth. The horseshoe crab doesn’t have a jaw. What it does is direct food into it’s mouth where the food is ground up by it’s gizzard which contains sand and small bits of gravel to help with the process

Long ago humans realized that horseshoe crabs could be useful in their everyday living. Native Americans used the shells of horseshoe crabs as tools and the tails as spear tips. They also discovered that the horseshoe crabs made good fertilizer as their bodies were high in Nitrogen. This knowledge was later passed on to the European settlers and was used up into the late 1900’s. More recently, scientists in the medical field have started to study the horseshoe crab for medical reasons. Research on the compound eyes of the horseshoe crab has lead to a greater understanding of how our own eyes work.

Frederick Bang In the 1950’s discovered that the blood of horseshoe crabs contained a clotting agent that when it comes in contact with certain types of bacteria it clots the blood and forms a gel that surrounds the bacteria. This allows for the bodies antibodies to take care of the bacteria. Bang and an associate created Limulus amoebocyte lysate or LAL which is now used to test for certain types of bacteria. Horseshoe crabs are captured and after they are inspected, blood is carefully bled. The procedure does not usually harm the horseshoe crabs and death rates are very low. One quart of LAL sells for $15,000.

horseshoe crabs shell

one of the compound eyes of a horseshoe crab

the hinge that joins the cephalothorax and opisthosoma.

a horseshoe crabs anus

Super close-up photo of a horseshoe crabs chelicerae

how a horseshoe crab can curl up for protection

open gills of a horseshoe crab

the book gills and flap cover genitalia of a horseshoe crab

male horseshoe crab upside down

movable spines of a horseshoe crab

the horseshoe crabs chelicerai (front pincers)

underside of a male horseshoe crab with barnacles

the mouth of a horseshoe crab

male horseshoe crabs mouth

front claws of a male horseshoe crab

male horseshoe crabs front leg

male horseshoe crabs pusher leg

male horseshoe crab close-up

a female horseshoe crabs underside

a female horseshoe crab flaps covering genitalia