IMTA utilizes the byproducts, such as waste, from one aquatic species to serve as inputs for another. In this system, b y integrating fed aquaculture with inorganic extractive components (e.g. aquatic plants) and organic extractive components (e.g. aquatic mollusks), farmers develop balanced systems aimed at environmental remediation. Aquaculture, while crucial for meeting the growing global demand for seafood, is facing increasing criticism for its contribution to greenhouse gas (GHG) emissions and climate change. Adopting IMTA in fish farming has been proven to minimize GHG emissions where one of the required organic extractives is aquatic mollusk.
This study involved two stages: first, gathering the community’s perception of snails in prawn farming using participatory appraisal tools like focus group discussions (FGDs), seasonal calendars, and ranking exercises, and second, identifying snails through direct field observation using the quadrate sampling method. This two-part research was conducted during the monsoon season (July-October) because snails thrive in water during this time, and people’s awareness of them is heightened. Three FGDs were conducted in the three zone according to the degree salinity such as low saline zone (Rangpur), intermediate saline (Botiaghata) and high saline zone (Dumuria ) in Khulna district of Bangladesh. From each of the sampling sites, three different types of waterbodies such as, gher (used for prawn and shrimp), aquaculture ponds (used for prawn and finfish culture) and non-aquaculture waterbodies (canal, wetlands, beel, derelict ponds, etc.) were selected. In each waterbody, at least three quadrates, each of 1m2 , were placed in a zig-zag pattern and the number and types of snail species within each quadrate were recorded.
The identified species through participatory appraisal tools were Macrochlamys sp., Bellamya sp., Neritina sp., Brotia sp., Pila sp., Lymnaea sp., Lamellidens sp., Sulcospira sp., Sulcospira sp., Sulcospira sp., and Melanoides sp. According to people’s perception, five species of mollusk , such as Bellamya sp., and Pila sp., Neritina sp., Lamellidens sp., and Sulcospira sp., were available in the prawn farming region during the longest period of the year. However, in quadrat sampling method, two species such as Bellamya sp., and Pila sp., were found most abundant irrespective of zone of salinity and waterbodies. Participants in the FGDs reported that these two species can be produced in IMTA ponds along with prawn, that may be used as animal and fish feed. Since there has not been much research on mollusk in Bangladesh, molecular genetic tools can be used for the advanced species- level identification of all those mollusks.