Batitis (Batissa violacea) is a freshwater clam originating in the Cagayan River, the largest river in the Philippines. This product is ecologically important and has socio- economic and cultural values.
The batitis mollusk is a large, thick- shelled bivalve with an ovate outline; the inside of the valves is purple as well as the exterior. The external part has also a thick black to olive covering (periostractum). It can be found in sandy or muddy beds of freshwater, brackish water, and mangrove swamps of the Philippines. In particular, it is found to inhabit sandy areas of the Cagayan River with a depth of 1.70- 6.20 mt and the bivalves increases its number when the water quality parameters are at optimum condition.
Bivalve collectors observe the siphons of the clam to trace their presence in the sand, especially when the water is clear. The collectors usually use locally dredging material (called tako) and boat in collecting the clam because it is simple. The collection is done during sunny days in which water is calm, clear and the water level is low. Generally, the time of the collection is very early in the morning. Since 2001 the use of destructive fishing gear were prohibited because it was seen to create disturbance to the habitat of mollusks and other fishery resource.
Batitis can be eaten both raw and cooked and can be salted or boiled. They are also used as a side dish with kalamansi and vinegar. Extracted from their shells, the creamy meat is preserved in a mild brine solution.
The Philippine government recently categorized batitis as a threatened species in the Cagayan River due to its dwindling stocks from 2000 to 2012, where studies have occurred. Several concerns have been raised on the ongoing uncontrolled harvesting of the bivalve which could likely lead to extinction of the resource.