Lalramchhani, C.; Balasubramanian, C.P.; Panigrahi, A.; Ghoshal, T,K.; Das, S.; Shyne Anand, P.S, and Vijayan, K.K., 2019. Polyculture of Indian white shrimp (Penaeus indicus) with milkfish (Chanos chanos) and its effect on growth performances, water quality and microbial load in brackishwater pond. In: Jithendran, K.P.; Saraswathy, R.; Balasubramanian, C.P.; Kumaraguru Vasagam, K.P.; Jayasankar, V.; Raghavan, R.; Alavandi, S.V., and Vijayan, K.K. (eds.), BRAQCON 2019: World Brackishwater Aquaculture Conference. Journal of Coastal Research, Special Issue No. 86, pp. 43-48. Coconut Creek (Florida), ISSN 0749-0208.

Polyculture has been well acknowledged as a strategy for sustainable aquaculture production. However, reports on polyculture of Indian white shrimp with other fish species are limited. In the present study, polyculture of Indian white shrimp (Penaeus indicus) and milkfish (Chanos chanos) was carried out to determine the species compatibility and the effect on growth performances, water quality and microbial load in a pond following biosecured zero-water exchange. Monoculture of P. indicus (25 no./m²) (T1) was compared with polyculture with milkfish at two stocking densities [(P. indicus- 25 PL m^-2, C. chanos- 0.25 no. m ^-2) (T2) and (P. indicus- 25 PL m^-2, C. chanos- 0.50 no. m^-2) (T3)] for 75 days with each treatment having similar sized replicate ponds. Significantly higher (p<0.05) average total ammonia nitrogen (TAN) and nitrite- nitrogen (NO₂-N) were recorded in T1 (145.20±13.50 µg/l and 84.18±16.62 µg/l, respectively), whereas polyculture ponds recorded TAN of 103.76±13.07 µg/l and 81.11±5.09 µg/l and NO₂-N- 45.23±9.41µg/l and 41.21±6.18 µg/l in T2 and T3, respectively. Significantly higher (p<0.05) ABW of pre-adult milkfish (148.04±4.15 g) was recorded in T2 compared to T3 (96.56±1.05 g), and production was also significantly (p<0.05) higher in T2 (482.73±3.24 kg/ha) compared to T3 (369.10.32±6.62 kg/ha). No significant difference (p<0.05) in apparent feed conversion ratio (AFCR) of shrimp was recorded among the treatments, although T3 recorded the best AFCR (1.65) compared to T1 (1.89) and T2 (1.77). There was no significant difference (p<0.05) in total heterotrophic aerobic bacteria (THAB) and total Vibrio (TV) loads in pond water among three different treatment groups. This study indicates that polyculture of P. indicus and milkfish is ecologically and economically beneficial compared to a monoculture of P. indicus.