In a major advancement for estuarine ecosystem restoration, the ICAR–Central Marine Fisheries Research Institute (CMFRI) has successfully induced captive breeding of the mangrove clam (Geloina erosa), a species experiencing rapid population decline.
The development is expected to support community-managed estuarine aquaculture models that are closely linked to mangrove conservation efforts. Mangrove clams, also called mud clams, are a key bivalve species found across mangrove and estuarine habitats in South and Southeast Asia. Despite their ecological significance, wild stocks have been dwindling, even as the clams remain a popular delicacy, particularly in northern Kerala, where they are locally known as ‘Kandal Kakka.’
The species inhabits organic-rich muddy substrates in intertidal mangrove zones. CMFRI scientists from the Mariculture Division successfully induced spawning in captive broodstock, completing the full embryonic and larval cycle under controlled conditions. Spat settlement was observed from the 18th day after spawning, confirming the feasibility of hatchery-based production of viable seeds.
This achievement represents one of the few global examples of successful induced breeding, larval rearing, and spat production of mangrove clams. CMFRI researchers are now standardising larval rearing and nursery management protocols to enhance survival rates and enable large-scale seed production.
Hatchery-produced seeds can be deployed in ranching programs within degraded or critical mangrove ecosystems, supporting both clam stock enhancement and mangrove habitat restoration. The initiative is expected to open sustainable livelihood opportunities and strengthen nutritional security for coastal communities, especially along the Kerala coast.
The breakthrough also provides a scientific solution to declining wild stocks across India, particularly along the east coast and island regions, where clam populations have suffered due to overharvesting, habitat degradation, pollution, and unregulated coastal development. Lack of stock assessments, size regulations, and seasonal harvesting controls has contributed to reduced abundance and smaller shell sizes.
The mangrove clam, one of the world’s largest mud clams with shells reaching up to 10 cm, plays an essential ecological role by recycling nutrients, stabilising sediments, and supporting mangrove ecosystems. It also underpins food security and livelihoods for communities dependent on coastal and estuarine resources.
Experts emphasise that combining hatchery-based seed production with grow-out farming in suitable estuarine environments could provide low-input, environmentally sustainable aquaculture solutions. Such initiatives are expected to reduce pressure on wild stocks while restoring depleted natural populations and providing stable income streams for coastal households.
CMFRI’s success marks a significant step towards integrating species conservation with community-centric aquaculture, offering both ecological and socio-economic benefits for mangrove-dependent regions.
