The role of pond snails on the accumulation of organic matter in fish ponds(Thai)

Abstract

This study on the role of pond snails in fish ponds was performed by farm survey and laboratory experiments. Three surveys of five fish farms were carried out in Khon Kaen Province, Thailand according to the seasons; summer, rainy and winter. Pond snails found in this study are in family Viviparidae. The average density of pond snails with weight, length and width of 2.82 to 18.2 g, 2.3 to 4.4 cm and 1.4 to 2.8 cm, respectively found in fish ponds was in the range of 78.7 to 91.7 pond snails/m2. The average density of pond snails in fish ponds varied seasonally (p < 0.05). The proximate analysis of pond snail flesh indicated protein content of 52.9 + 1.24 % on dry weight basis. Study of utilization pathway of organic matter accumulated in fish ponds by pond snails was performed by three laboratory experiments. Increasing surface area of substrates in experimental units indicated a higher reduction of organic matter in sediment (p< 0.05). Furthermore, small pond snails may prefer feeding on living organisms rather than organic matter.