{"product_id":"horseshoe-crab-limulus-polyphemus","title":"Horseshoe Crab Limulus Polyphemus","description":"\u003cstrong\u003eHorseshoe Crab (Limulus polyphemus)\u003c\/strong\u003e\u003cp\u003e\u003cem\u003e(Also known as Atlantic Horseshoe Crab, American Horseshoe Crab, or King Crab)\u003c\/em\u003e\u003c\/p\u003e\n\u003cstrong\u003eOverview\u003c\/strong\u003e\u003cp\u003eThe Horseshoe Crab (\u003cem\u003eLimulus polyphemus\u003c\/em\u003e) is an ancient and fascinating \u003cstrong\u003emarine arthropod\u003c\/strong\u003e, often referred to as a “living fossil” — having remained virtually unchanged for over \u003cstrong\u003e450 million years\u003c\/strong\u003e. Despite its name, it is \u003cstrong\u003enot a true crab\u003c\/strong\u003e, but more closely related to spiders and scorpions. Recognisable by its \u003cstrong\u003ehard, domed carapace\u003c\/strong\u003e, \u003cstrong\u003espiny tail spine (telson)\u003c\/strong\u003e, and \u003cstrong\u003emultiple pairs of legs\u003c\/strong\u003e, this species plays an important ecological role as both a \u003cstrong\u003esubstrate cleaner\u003c\/strong\u003e and \u003cstrong\u003esand sifter\u003c\/strong\u003e. While captivating, Horseshoe Crabs grow very large and require specialised care, making them suitable only for \u003cstrong\u003eexperienced aquarists with very large marine systems\u003c\/strong\u003e.\u003c\/p\u003e\n\u003cstrong\u003eOrigin\u003c\/strong\u003e\u003cp\u003eNative to the \u003cstrong\u003ewestern Atlantic Ocean\u003c\/strong\u003e, including the \u003cstrong\u003eGulf of Mexico\u003c\/strong\u003e and \u003cstrong\u003eeastern coast of North America\u003c\/strong\u003e, from Maine to the Yucat√°n Peninsula. Found primarily in \u003cstrong\u003eshallow coastal waters, sandy lagoons, and estuaries\u003c\/strong\u003e, where they burrow into soft substrates searching for food.\u003c\/p\u003e\n\u003cstrong\u003eFeeding\u003c\/strong\u003e\u003cp\u003eHorseshoe Crabs are \u003cstrong\u003eomnivorous scavengers\u003c\/strong\u003e, feeding primarily on benthic organisms and detritus. In captivity, they require a diet rich in protein and organic material. Feed \u003cstrong\u003eseveral times weekly\u003c\/strong\u003e with:\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003eMysis shrimp, krill, or chopped clams\n\u003c\/li\u003e\n\u003cli\u003eMarine pellets and sinking wafers\n\u003c\/li\u003e\n\u003cli\u003eDetritus, leftover food, and organic debris from the substrate\n\u003c\/li\u003e\n\u003cli\u003eOccasional algae-based supplements\n\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003eThey use their legs and mouth appendages to sift sand and locate buried food. A deep, soft substrate is essential for natural foraging behaviour.\u003c\/p\u003e\n\u003cstrong\u003eLighting\u003c\/strong\u003e\u003cp\u003e\u003cstrong\u003eLow to moderate lighting.\u003c\/strong\u003e Horseshoe Crabs do not rely on light for feeding or activity. Provide subdued illumination and shaded areas to mimic their natural, shallow coastal environment.\u003c\/p\u003e\n\u003cstrong\u003eWater Flow\u003c\/strong\u003e\u003cp\u003e\u003cstrong\u003eModerate, gentle flow.\u003c\/strong\u003e Ensure adequate oxygenation and stable circulation without excessive current that could disturb the substrate or flip the crab.\u003c\/p\u003e\n\u003cstrong\u003ePlacement \u0026amp; Habitat Setup\u003c\/strong\u003e\u003cul\u003e\n\u003cli\u003eProvide \u003cstrong\u003edeep sandy substrate\u003c\/strong\u003e (7–10 cm \/ 3–4 inches) for burrowing and foraging.\n\u003c\/li\u003e\n\u003cli\u003eAvoid sharp rocks or coarse gravel, which can damage the carapace or legs.\n\u003c\/li\u003e\n\u003cli\u003eEnsure the tank is large enough for movement and full burrow cycles.\n\u003c\/li\u003e\n\u003cli\u003eKeep the environment \u003cstrong\u003ewell-oxygenated\u003c\/strong\u003e and free of debris buildup.\n\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cstrong\u003eTank Mates\u003c\/strong\u003e\u003cp\u003e\u003cstrong\u003eCaution required.\u003c\/strong\u003e Compatible with:\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003ePeaceful, slow-moving fish (gobies, blennies, jawfish)\n\u003c\/li\u003e\n\u003cli\u003eNon-aggressive invertebrates (snails, cucumbers, brittle stars)\n\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003eAvoid:\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003ePredatory fish (triggers, puffers, large wrasses)\n\u003c\/li\u003e\n\u003cli\u003eCrustaceans that may nip at legs or eyes\n\u003c\/li\u003e\n\u003cli\u003eSharp rock structures that could trap or injure the crab\n\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cstrong\u003eAggression\u003c\/strong\u003e\u003cp\u003e\u003cstrong\u003ePeaceful.\u003c\/strong\u003e Horseshoe Crabs do not attack other tank inhabitants but may unintentionally disturb corals or rockwork while burrowing.\u003c\/p\u003e\n\u003cstrong\u003eExperience Level\u003c\/strong\u003e\u003cp\u003e\u003cstrong\u003eAdvanced.\u003c\/strong\u003e\u003cem\u003eLimulus polyphemus\u003c\/em\u003e requires \u003cstrong\u003every large aquariums\u003c\/strong\u003e, \u003cstrong\u003edeep sand\u003c\/strong\u003e, and \u003cstrong\u003eexcellent water quality\u003c\/strong\u003e. Most specimens are better suited to public aquariums or large, open marine systems. Juveniles can adapt to home tanks but often outgrow them quickly.\u003c\/p\u003e\n\u003cstrong\u003eWater Parameters\u003c\/strong\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eTemperature:\u003c\/strong\u003e 22–27°C (72–81°F)\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003epH:\u003c\/strong\u003e 8.1–8.4\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eSalinity:\u003c\/strong\u003e 1.024–1.026 SG\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eHardness (dKH):\u003c\/strong\u003e 8–12\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eAmmonia \/ Nitrite:\u003c\/strong\u003e 0 ppm\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eNitrate:\u003c\/strong\u003e \u0026lt;10 ppm\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eTank Size:\u003c\/strong\u003e Minimum \u003cstrong\u003e500 gallons (1,900L)\u003c\/strong\u003e for adult specimens; \u003cstrong\u003e200 gallons (750L)\u003c\/strong\u003e for juveniles\n\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003eStable salinity and oxygen levels are essential, as Horseshoe Crabs are sensitive to rapid environmental fluctuations.\u003c\/p\u003e\n\u003cstrong\u003eLifespan \u0026amp; Size\u003c\/strong\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eSize:\u003c\/strong\u003e Up to \u003cstrong\u003e60 cm (24 inches)\u003c\/strong\u003e across including tail spine\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eLifespan:\u003c\/strong\u003e Up to \u003cstrong\u003e20 years\u003c\/strong\u003e in the wild; typically \u003cstrong\u003e5–10 years\u003c\/strong\u003e in captivity with proper care\n\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cstrong\u003eReef Compatibility\u003c\/strong\u003e\u003cp\u003e\u003cstrong\u003eNot reef safe.\u003c\/strong\u003e While peaceful, Horseshoe Crabs can \u003cstrong\u003edislodge rocks, overturn corals\u003c\/strong\u003e, and \u003cstrong\u003edisturb substrate-dwelling invertebrates\u003c\/strong\u003e during feeding. Best kept in \u003cstrong\u003efish-only\u003c\/strong\u003e or \u003cstrong\u003especialised species tanks\u003c\/strong\u003e with soft sand and minimal rockwork.\u003c\/p\u003e\n\u003chr data-start=\"4381\" data-end=\"4384\"\u003e\u003cbr\u003e\u003cbr\u003e\u003cstrong\u003e‚ö†Ô∏è \u003cstrong\u003eImportant Note\u003c\/strong\u003e\u003cp\u003eDue to their \u003cstrong\u003elarge adult size and deep-sand habitat requirements\u003c\/strong\u003e, Horseshoe Crabs are \u003cstrong\u003enot suitable for most home aquariums\u003c\/strong\u003e. Many individuals are sold as juveniles but quickly outgrow standard tanks. Only advanced aquarists with spacious systems or public aquarium setups should attempt long-term care.\u003c\/p\u003e\u003c\/strong\u003e","brand":"Real Aquatics","offers":[{"title":"Default Title","offer_id":56864439337335,"sku":"FSH-01844","price":49.99,"currency_code":"GBP","in_stock":false}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0537\/0386\/8610\/files\/Horseshoe-Crab-Limulus-Polyphemus.png?v=1773332002","url":"https:\/\/realaquatics.co.uk\/products\/horseshoe-crab-limulus-polyphemus","provider":"Real Aquatics","version":"1.0","type":"link"}