Merostomata | 
Xiphosura | 
Limulidae
			
			
			
				Environment: milieu / climate zone / depth range / distribution range				
				
					Ecology				
				
			
			
				Benthic; depth range 3 - 11 m (Ref. 76).  Tropical, preferred 24°C (Ref. 107945)			
			
			
				
			
			
			
				Western Atlantic:  from Maine, USA to Mexico.
			
			
			
			
			
				Length at first maturity / Size / Weight / Age
			
			
				Maturity: Lm ?  range ? - ? cm Max length : 60.0 cm TL male/unsexed; (Ref. 82); max. published weight: 1.8 kg (Ref. 82); max. reported age: 20 years (Ref. 99652)			
			
			
						
			
			
			
			
				
					The males are approximately 1/3 the size of the females (sexual dimorphism) (Ref. 83). Lives in shallow waters, with sandy or muddy bottoms (Ref. 76).  Found in intertidal and offshore areas (Ref. 1131).  The horseshoe crab feeds at night on polychaete worms such as Cerebratulus, Nereis, and Cistenides (Ref. 76, 77), small mollusks, and seaweed (algae) found in the sandy ocean bottom (Ref. 76).  Food is picked up by the chelicerae and passed back to the bristle bases, where it is "chewed." The food is then moved forward to the mouth (Ref. 75).  It digs its food from sediments, grasping the prey with its legs.  The prey is moved to the gnathobases where it is crushed before being pushed forward toward the mouth (Ref. 77).   A life span of about 20 to 40 years (Ref. 78).   Its predators are loggerhead turtles, pufferfish, leopard sharks and sea gulls (Ref. 82).				
			
			
			
			
			
				Life cycle and mating behavior				
					Maturity | Reproduction | Spawning | Eggs | Fecundity | Larvae				
			
			
				
					They reproduce with the use of the first pair of the six, flap-like appendages on the underside of the abdomen acts as a cover for the genital pore.  The egg or sperm are released through this pore during spawning (Ref. 75).  These eggs are fertilized by sperm released by an attached male and by one or more satellite males that typically congregate around the nesting pair (Ref. 81).  While nesting, females bury themselves in the sediment near the water's edge and lay a series of discrete egg clusters, each containing 2,000-20,000 eggs (Ref. 80).				
			
			
			
			
			
				Lee, C.N. and B. Morton 2005 Experimentally derived estimates of growth by juvenile Tachypleus tridentatus and Carcinoscorpius rotundicauda (Xiphosura) from nursery beaches in Hongkong. Journal of Experimental Marine Biology and Ecology 318:39-49. (Ref. 1131)
			
			
			
			
			
			
			
					
						IUCN Red List Status    
						 (Ref. 130435: Version 2025-1)
					
					
					
				
			
			
			
			
				CITES status   (Ref. 108899)
			
			
				
					Not Evaluated				
			
			
			
			
			
			
				
					Not Evaluated				
			
			
			
			
			
				Threat to humans  
			
			
				
					  Harmless				
			
			
			
			
			
			
			
			
				Human uses  
			
			
				Fisheries: commercial			
			
			
				FAO - Fisheries: landings | FIRMS (Stock assessments) | FishSource | Sea Around Us			
			
			
			
			
			
Tools
			
			
			
			
				
					More information				
				
					 PhysiologyOxygen consumption
  Human RelatedStamps, coins, misc.
  
			 
			
			
			
				Internet sources
			
			
			
			
			
				Estimates based on models
			
			
			
									
						Preferred temperature  					
				 (Ref. 
115969): 12.5 - 28, mean 26.7 (based on 417 cells).			
 
			
			
			
			
			
						
							
				
					
						Fishing Vulnerability  					
					
					
						High to very high vulnerability (66 of 100).					
				
						
							
					
						Climate Vulnerability  					
					
					High to very high vulnerability (75 of 100).				
						
			
			
			
				Nutrients  :  Calcium = 126 [75, 177]  mg/100g; Iron = 4.79 [1.67, 7.92]  mg/100g; Protein = 16.6 [15.4, 17.8] %; Omega3 = 0.331 [0.263, 0.400]  g/100g; Selenium = 57.8 [48.5, 67.2]  μg/100g; VitaminA = 0 μg/100g; Zinc = 1.97 [0.92, 3.02]  mg/100g (wet weight); based on 
nutrient studies.