Bivalvia | 
Arcida | 
Arcidae
			
			
			
				Environment: milieu / climate zone / depth range / distribution range				
				
					Ecology				
				
			
			
				Benthic; brackish; depth range 0 - 20 m (Ref. 101198).  Tropical, preferred 27°C (Ref. 107945); 46°N -   39°S, 26°E -   134°W (Ref. 106948)			
			
			
				
			
			
			
				Indo-Pacific.
			
			
			
			
			
				Length at first maturity / Size / Weight / Age
			
			
				Maturity: Lm ?, range 2 -  2.1 cm Max length : 9.0 cm SHL male/unsexed; (Ref. 348); common length : 6.0 cm SHL male/unsexed; (Ref. 348); max. reported age: 12 years (Ref. 126573)			
			
			
							
				
				
					
						Shell equivalve, thick and solid, ovate, strongly inflated, slightly longer than high and feebly inequilateral.  Umbones strongly protruding, cardinal area rather large.  About 18 radial ribs (15 to 20) with wide interstices at each valve; ribs stout and distinctly rugose, bearing regular, often rectangular nodules.  Periostracum rather thin and smooth.  Internal margins with strong crenulations corresponding with the external radial ribs.  No byssal gape.  Colour:  outside of shell white under the yellowish brown periostracum.  Inner side white, often tinged yellow towards the umbonal cavity.					
				
				
						
			
			
			
			
				
					This represents the most important commercial ark (Ref. 348). Lives in intertidal and shallow subtidal waters.  On muddy bottoms, mainly in protected bays and estuaries, or in mangroves.  Often occurring in dense populations (Ref. 348).  Typically found in the intertidal with silty bottoms with low salinity.   A filter-feeder and a  shallow burrower.  Primarily feeds on organic detritus, phytoplankton and detritus (Ref. 101198).				
			
			
			
			
			
				Life cycle and mating behavior				
					Maturity | Reproduction | Spawning | Eggs | Fecundity | Larvae				
			
			
				
					Members of the class Bivalvia are mostly gonochoric, some are protandric hermaphrodites.  Life cycle:  Embryos develop into free-swimming trocophore larvae, succeeded by the bivalve veliger, resembling a miniature clam.				
			
			
			
			
			
				Poutiers, J.M. 1998 Bivalves. Acephala, Lamellibranchia, Pelecypoda. p. 123-362. In Carpenter, K. E. and V. H. Niem. 1998. FAO species identification guide for fishery purposes. The living marine resources of the Western Central Pacific. Volume 1. Seaweeds, corals, bivalves, and gastropods. Rome, FAO. (Ref. 348)
			
			
			
			
			
			
			
					
						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 - Aquaculture: production; Fisheries: landings, species profile | FishSource | Sea Around Us			
			
			
			
			
			
Tools
			
			
			
			
				
					More information				
				
					 PhysiologyOxygen consumption
  Human RelatedStamps, coins, misc.
  
			 
			
			
			
				Internet sources
			
			
			
			
			
				Estimates based on models
			
			
			
									
						Preferred temperature  					
				 (Ref. 
115969): 21.8 - 29.3, mean 28.4 (based on 3701 cells).			
 
			
			
			
							
					Resilience  				
				
				
					High, minimum population doubling time less than 15 months (K=0.54-4.34; tm=0.6; tmax=12).				
			
			
							
					 Prior r = 0.85, 95% CL = 0.56 - 1.28, Based on 2 data-limited stock assessments.				
						
							
				
					
						Fishing Vulnerability  					
					
					
						Low to moderate vulnerability (28 of 100).					
				
						
							
					
						Climate Vulnerability  					
					
					High vulnerability (61 of 100).				
						
			
			
			
				Nutrients  :  Calcium = 149 [71, 228]  mg/100g; Iron = 8.53 [1.95, 15.11]  mg/100g; Protein = 9.88 [8.64, 11.12] %; Omega3 = 0.313 [0.202, 0.423]  g/100g; Selenium = 61 [50, 72]  μg/100g; VitaminA = 0 μg/100g; Zinc = 2.04 [0.56, 3.51]  mg/100g (wet weight); based on 
nutrient studies.