The ICAR–Central Marine Fisheries Research Institute (CMFRI) has achieved a rare global scientific feat by successfully inducing captive breeding of the mangrove clam (Geloina erosa). This breakthrough enables controlled hatchery production of the species, offering a sustainable pathway for conservation, aquaculture, and ecosystem restoration.

About Mangrove Clam (Geloina erosa)

• Scientific name: Geloina erosa (also referred to in some literature as Polymesoda erosa)
• Common name: Mangrove clam / Mud clam
• Local name: “Kandal Kakka” (Northern Kerala)
• Type: Ecologically significant bivalve mollusc

Habitat and Distribution

• Found in organic-rich muddy substrates of intertidal mangrove and estuarine ecosystems
• Distributed across South and Southeast Asia
• Tolerates a wide salinity range, from brackish to near-freshwater conditions
• Deep-burrowing, semi-infaunal species; juveniles are more tide-independent

Key Ecological Characteristics

• Large Size:
  • One of the world’s largest mangrove clams
  • Reaches up to 10 cm shell width, making it valuable as a food resource
• Efficient Filter Feeder:
  • Filters suspended particles and plankton
  • Improves estuarine water quality through nutrient recycling
• Ecosystem Stabiliser:
  • Burrowing behaviour stabilises sediments
  • Enhances nutrient cycling
  • Strengthens resilience of mangrove ecosystems
• Reproductive Biology:
  • Sex differentiation based on gonad colour and structure (not external organs)
  • Facilitates broodstock identification and reproductive studies

Scientific Breakthrough: Induced Breeding

CMFRI has achieved:

• Controlled spawning under captive conditions, reducing dependence on wild seed collection
• Complete life-cycle closure, successfully rearing the clam from embryo to larval stages and eventually to spat (around the 18th day)
• Hatchery-scale seed production feasibility

This represents a global first for this species and marks a major step in sustainable marine resource management.

Conservation and Aquaculture Applications

The hatchery-produced seeds can be utilised for:

• Grow-out farming:
  • Suitable for estuarine aquaculture
  • Requires minimal external feed and infrastructure
• Mangrove ranching:
  • Release of juvenile clams into degraded mangrove habitats
  • Aids ecological restoration
• Stock enhancement:
  • Replenishes overexploited natural clam beds
  • Reduces harvesting pressure on wild populations