Department of Agriculture and Rural Development), a list of farms
which raised juvenile giant gourami during the period of February–
June 2012 in Cai Be, Cai Lay and Chau Thanh districts was compiled.
Ponds were divided into two groups based on approximate water
depth (either b1 m or N1 m) and from each group 30 nurseries were
randomly selected. The selected ponds were from a total of 13 communes
within the three districts (1–13 ponds per commune). Pond
depth was later measured in the middle of the pond using a measuring
stick and at points 2maway fromthe pond edge. Generally ponds had a
flat bottom and depth varied little (0.05–0.2 m) once the sloping sides
reach the maximum depth less than 2 m from the pond edge. Seven
ponds had depths in the range 0.4–0.5 m, 9 ponds 0.6–0.7 m, 14
ponds 0.8–0.9 m, 10 ponds 1.0–1.1 m and the remaining 20 ponds had
depths in the range 1.2–1.3 m. To confirm the pond characteristics we
visited all selected ponds while they were emptied in preparation for
the next stocking of fry. Surface area of the ponds ranged from 300 to
5000 m2. Pond volume was estimated by assuming that average depth
in the section from the pond edge to 2 m from the edge was 0.7 of the
depth in the middle of the pond.
We obtained information on pond preparation prior to stocking fry,
i.e. number of days the pondwas allowed to dry and the amount of lime
applied to the pond bottom (kg per 100 m2 surface area).
Stocking records were obtained fromeach farmer and stocking densitywas
calculated as the number of fry stocked divided by the estimated
volume of water or surface area.