Bivalvia | Arcoida
Environment / Climate / Range
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)
Length at first maturity / Size / Weight / Age
Maturity: Lm ?, range 2 - 2.1 cm Max length : 9.0 cm TL male/unsexed; (Ref. 348); common length : 6.0 cm TL male/unsexed; (Ref. 348)
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). 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 (Ref. 833). Spawns throughout the year, with peaks in January and April (Ref. 75727).
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. (Ref. 348)
IUCN Red List Status (Ref. 115185)
CITES status (Ref. 108899)
Threat to humans
FAO(Aquaculture: production; fisheries: production) | FisheriesWiki | Sea Around Us
Estimates of some properties based on models
): 21.8 - 29.3, mean 28.4 (based on 3701 cells).
Low vulnerability (10 of 100)