Common name: Horseshoe crab
General information
The Horseshoe Crab, Limulus polyphemus, is an ancient marine arthropod that is more closely related to spiders and scorpions than to true crabs. Despite its name, it is not a crab at all. These creatures have been around for over 450 million years, making them living fossils. They have a hard exoskeleton, a long, pointed tail spine (telson), and a unique, horseshoe-shaped carapace.
Details
- Recommended minimum tank volume
- 2,000 liter (530 gallons)
- Salinity
- S.G. 1.020 to 1.025
- Temperature
- 16 to 24 °C (61 to 75 °F)
- Acidity
- pH 7.8 to 8.3
- Average size
- 60 cm (2′)
- Care level
- Very difficult Needs very large space, not for home aquariums
- Diet
- Omnivore Scavenges, eats worms, algae, detritus
- Reefsafe
- No May disrupt tank environment
- Aggression
- Peaceful Non-aggressive but can harm with size
- Captive bred
- No
Taxonomy
- KingdomAnimalsAnimalia
- PhylumArthropodsArthropoda
- ClassHorseshoe CrabsMerostomata
- OrderHorseshoe CrabsXiphosurida
- FamilyHorseshoe crabsLimulidae
- GenusHorseshoe CrabLimulus
- SpeciesHorseshoe crabLimulus polyphemus (Linnaeus, 1758)
- SynonymsLimulus albus Bosc, 1802Limulus americanus Leach, 1819Limulus cyclops Fabricius, 1793Limulus occidentalis Lamarck, 1801Limulus sowerbii Leach, 1815
Care
Horseshoe Crabs are not commonly kept in home aquariums due to their large size and specialized needs. They require spacious tanks with a deep sand bed for burrowing and a variety of live foods to scavenge. Their diet in captivity can include mollusks, worms, and other small invertebrates.
Reproduction
Horseshoe Crabs are known for their spectacular spawning events on beaches during the spring and summer full moons. Females lay thousands of eggs in the sand, which are then fertilized by the males. In captivity, breeding is rare and requires a large, species-specific setup.
Symbiosis
While not typically involved in symbiotic relationships within an aquarium setting, Horseshoe Crabs play a crucial ecological role in their natural habitat. Their eggs provide a vital food source for migrating shorebirds, and their scavenging helps to clean the environment.
Habitat
Limulus polyphemus is found along the Atlantic coast of North America, from Maine to the Yucatan Peninsula. They inhabit shallow ocean waters and estuaries, often burying themselves in sandy or muddy substrates.