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Field Update: Horseshoe Crab Research Project

Last year, our Animal Health team traveled to the Delaware coast to conduct baseline research on horseshoe crabs. 

Published July 06, 2016

Often referred to as “living fossils,” horseshoe crabs are truly amazing aquatic invertebrates! Although they’ve existed on our planet for over 300 million years, these species have changed very little in body morphology (shape).


Before opening our Living Seashore exhibit last May (which highlights the horseshoe crab), Aquarium staff needed to develop a health assessment parameter for the species. The initial part of the study sought to specifically understand the blood parameters of the normal and healthy horseshoe crabs found along our coast.

In close collaboration with the Delaware Department of Natural Resources, our team was able to collect small hemolymph (blood) samples from 100 specimens along the shore last Spring.

To obtain these samples, crabs were collected in the water and handled for one to two minutes. This ensured that the team wouldn’t interfere with any active reproduction. Horseshoe crabs have an intricate method of reproduction that relies on the moon and tides to accomplish, so it was imperative that our team did not disturb their mating processes.


Of particular interest to our team was the copper level found in thee samples. Horseshoe crabs use a copper-heavy protein to help carry oxygen to different parts of their body. The copper gives the blood of these animals a distinctive blue hue!

By understanding what the baseline level of copper in the blood for these animals is, our Animal Health team can closely monitor the animals in our exhibit for anemia.

To learn more about these amazing animals, click here.

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