1. MUSSEL FARMING

2. MUSSEL FARMING The important genera -are Mytilus and Perna
The major mussel producing countries - Spain, the Netherlands, France and Italy
The species cultured : 
Mytilus edulis – the Netherlands, France and Spain
Mytilus galoprovincialis – Italy, Yugoslavia and Russia
Mytilus smaragdinus = Perna viridis – the Philippines.
Mytilus edulis
Mytilus galoprovincialis
Mytilus smaragdinus

3. Life History
Mussels - filter feed on phytoplankton and suspended organic matter
Reach sexual maturity in first year
Spawn with rising temperature in the temperate region and almost throughout the year in tropics
Sexes are separate, fertilization external

4. Larvae pass through trochophore and veliger stage, both are planktonic
When they reach a shell length of 0.25 to 0.3mm, after days, they attach to hard substratum such as rocks by means of byssus threads
They can detach and reattach to different substrates
They conglomerate and form thickly populated beds on rocks and other substratum mainly in the sub-tidal areas of the sea

6. Grow-out
CMFRI – farming of green mussel Perna viridis - raft culture method
Rafts - fabricated using wooden/bamboo poles tied together with nylon/coir ropes
The poles are treated with coal tar to enhance their life
Raft - 6x5 or 8x8m

7. Rafts mounted on 5 empty sealed drums of 200L capacity, painted with anti-corrosive paint
Wooden planks are fixed on the raft to provide for working space
Rafts are anchored in the protected areas of the sea using 3 iron anchors each weighing 100 kg at a depth ranging from 8-10m in the sea 1-1.5Km way from the shore
Ropes with seed attached to them are suspended form the raft for growing to marketable size

8. Seed collection
Seeds - from natural mussel beds
Cleaned in seawater to remove mud and epifauna
Size of the seed ranges from 20-30mm
The seed are secured to nylon/coir ropes by enclosing them in a knitted cotton cloth of 25cm with and stitching it around the rope
500 to 700 juveniles are attached to each meter of the rope
Diameter of the coir rope mm; nylon rope -14mm
Lengths of the ropes - 5-8mm
Seeded ropes are attached 0.5 to 1m apart to the rafts suspended in the sea
Seed mussels get attached to the ropes by byssus threads in 2-3 days and the cloth cover disintegrates in about 10 days

9. Growth and production
The seeded mussels grow to 36g in 5 months
Each rope yield about Kg/m
100 ropes of 6m length in a raft of 8x8m will yield 4800Kg per raft assuming an average production of 8Kg per m of the rope
Management of rafts
Collected mussels should be seeded within 24h.
Periodic inspection of rafts to detect leakage in floats, damage to rafts or ropes
Farm area should be demarcated with lights and flags to avoid damage by fishing boats.
Periodical cleaning and thinning of mussels to improve growth rates

10. Fouling organisms
Barnacles attach themselves to ropes and mussels with 30 days of seeding the ropes
More fouling takes place in the upper 2 m of the rope
Heavy fouling by a bivalve Mytilaster arculatula takes place in the months of November and December
Other fouling organisms are tubiculous polychaetes, Ascidians, Cnidarians and Bryozoans
Should be manually cleaned periodically
Predation
Predation by fish Rhabdosargus sarba
Net enclosures around the rafts will eliminate predation.
Fouling organisms
Rhabdosargus sarba