Class Merostomata Notes

Post on 09-Jan-2017

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Phylum Arthropoda

Subphylum Chelicerata

Class Merostomata

Phylum Arthropoda

Subphylum Chelicerata

Class Merostomata

Common name Horseshoe Crabs

Phylum Arthropoda

Subphylum Chelicerata

Class Merostomata

Common name Horseshoe Crabs

Horseshoe crabs are ancient animals. Only five species remain today but 200 million years ago there were hundreds of species.

This fossilized, ancient species is very similar to modern species.

Like other Arthropods, horseshoe crabs have compound eyes.

Horseshoe crabs are marine and must be able to absorb oxygen from the water.

Horseshoe crabs are marine and must be able to absorb oxygen from the water.

To do so, they have a series of seven “book gills” under their abdomen.

Horseshoe crabs are marine and must be able to absorb oxygen from the water.

To do so, they have a series of seven “book gills” under their abdomen. They’re called book gills because they look like pages in a book.

CarapaceAbdomen

8 legsTelson = 5 segments of the abdomen.

Book gills

Horseshoe Crabs come ashore to mate during the highest high tide in June. They lay their eggs in the sand.

Horseshoe crab eggs are an important food source for many animals.

Upon hatching, Horseshoe crab larvae look very much like Trilobites.

Upon hatching, Horseshoe crab larvae look very much like Trilobites.

This has lead scientists to infer that Trilobites might be the evolutionary ancestors of Horseshoe Crabs.

Upon hatching, Horseshoe crab larvae look very much like Trilobites.

This has lead scientists to infer that Trilobites might be the evolutionary ancestors of Horseshoe Crabs.

Horseshoe crab larvae are referred to as “trilobite larvae”.

When they come ashore, pharmaceutical companies collect them and take half of their blood.

It has amazing clotting ability.

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When they come ashore, pharmaceutical companies collect them and take half of their blood.

It has amazing clotting ability.

Proteins in it are separated and use to

Treat people who have Hemophilia, a disease that prevents the blood from clotting.

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