Shellfish production in Thailand has ranged between 50,000 and 300,000 mt over the past twenty years, with recent production around 120,000 mt/yr. Major species are green (Perna viridis ) and horse mussels (Modiolus senhausenii ) making some 60% of total production. The other main types, in order, are short-necked clams (Paphia undulata ) ark shells (Andara granosa ) and oysters (Crassostrea sp.). Culture practices account for 80% of green mussel, cockle and oyster production. Culture began to boom in the mid-seventies following a decline in production of the fisheries. There is a small export trade to Hong Kong and Singapore. The Thais import about 10,000 tons of cockles from Malaysia each year.