Horseshoe Crab

Limulus polyphemus


(17 Reviews)

Horseshoe Crab
Dive into prehistory with the Horseshoe Crab, an ancient marvel with a captivating helmet-like shell. Easy to care for and a natural cleaner, its unique shape and intriguing behavior make it a fascinating addition to any large saltwater aquarium.

Horseshoe Crab

Limulus polyphemus


(17 Reviews)

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Horseshoe Crab Care Facts

Care Level: Easy
Temperament: Peaceful
Diet: Omnivore
Reef Safe: Yes
Minimum Tank Size: 200 Gallons
Max Size: 18 inches
The Horseshoe Crab, Limulus polyphemus, is often called a living fossil as it is one of the world's oldest surviving organisms. It actually isn't a crab but more closely related to terrestrial scorpions and spiders. Its body is comprised of three main parts: the prosoma - its head region, the opisthosoma - its abdominal region, and the telson - its spine-like tail. It also has five pairs of jointed legs and a pair of pincers. Like some other inverts, it will occasionally molt is exoskeleton. 
 Its long tail helps it steer as it swims and right itself when upended onto its back. In the home aquarium it is best to keep the Horseshoe Crab in a tank with a deep sand bed as they like to burrow and search for food. This makes them great sand aerators. They are effective scavengers that will feed on worms, algae, and other meaty organisms found in the sediment. At its small size, the Horseshoe Crab is reef safe but may become more aggressive as it get larger. 


Reviewed by: Javier Gonzalez on Oct. 28, 2024


Reviewed by: Scott Kosters on Oct. 14, 2024

Very unusual behavior for one of these instead of burying in the sand it loves to go all over the tank exploring i love it


Reviewed by: William Welch on Oct. 8, 2024

Like having a pokemon


Reviewed by: Pepper Brandon on Oct. 7, 2024

I love it, but again ity dug into the sand and we have not seen it, since its disappering act in the sand.


Reviewed by: James Francisco on Jan. 2, 2024


Reviewed by: Shaun Huddleston on Dec. 28, 2023


Reviewed by: Micah Clark on Dec. 18, 2023


Reviewed by: Debbie Konechney on Dec. 11, 2023


Reviewed by: William Nesselrotte on Dec. 5, 2023

Love the unique addition very active


Reviewed by: Mary Fetterley on Dec. 3, 2023

He’s arrived in great condition. He’s thriving


Reviewed by: Claire Deyoung on Nov. 27, 2023

Doing good


Reviewed by: David Orear on Nov. 15, 2023


Reviewed by: Brittney Thornton on Aug. 10, 2023


Reviewed by: Debbie Konechney on Aug. 7, 2023

Horseshoe crabs are my favorite animal and awsome animals too!, but I have one slight complaint, horseshoe crabs are more closely related to spiders and scorpions than crabs, so I think you should put them under the category miscellaneous. Overall a amazing animal and keep on selling them because I want to buy more of these prehistoric living fossils!


Reviewed by: Ashton on Feb. 12, 2018

These little guy is great. You don't see him very much.But he keeps the sand bed very clean the tank.


Reviewed by: Raymond Schrefel on Sept. 17, 2017

Horseshoe Crabs are a neat addition to any tank. Not only are these dinosaurs cool to look at, they also do a great job of keeping your sand filtered and clean. While it's unfortunate that they don't come out very often when the lights are on, they can be seen from time to time when the lights are off.


Reviewed by: Phillip A Thrasher Jr on April 26, 2015

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