WWW.WAS.ORG • WORLD AQUACULTURE • DECEMBER 2024 35 of the polychaetes required for its growing aquaculture industry, particularly for shrimp hatcheries. With 315 hatcheries currently registered with the Government of India for seed production of Penaeus vannamei (CAA 2023), the demand for polychaete worms has surged significantly and is estimated to be between 252 and 337 tonnes annually (Pawar et al. 2022). The study of polychaetes from the Lakshadweep islands is limited, and many of the islands are not explored yet. Several polychaete species are native to Lakshadweep, including Glycera sp., Ceratonereis sp., Nematonereis sp., Nereis sp., Marphysa sp. and Eurythoe matthaii (Susan et al. 2011). These species are well-suited for breeding programs and polychaete culture. Regions like Lakshadweep, where the marine environment remains relatively unpolluted, are suitable and ideal locations for developing SPF polychaetes. These islands offer a naturally bio-secured environment, largely untouched and isolated, with minimum risk of pathogen contamination (Figure 1). Moreover, the polychaete diversity of these waters remains largely unexplored and there are more opportunities to get new species from these islands. The initiative to promote SPF polychaete culture in Lakshadweep will open significant opportunities for local economic development. The establishment of culture techniques and grow-out facilities can create new openings and can provide an alternative livelihood to the local islanders, particularly women, by involving them in the cultivation of polychaetes in a participatory approach. Initiative of ICAR-NBFGR to Develop Polychaete Culture The present paper describes the ICAR-NBFGR’s novel initiatives to develop culture of polychaete worms native to an island in Lakshadweep, with promising results. Polychaetes collected from Agatti island, Lakshadweep are significantly larger (36-38 cm) compared to those found on the mainland. Hence the archipelago appears to be an ideal site for polychaete breeding and aquaculture purposes. Moreover, ICAR-NBFGR has achieved initial experimental success in the captive breeding of these polychaetes, demonstrating the feasibility of producing SPF stocks in controlled environments (Figures 2 and 3). The initial screening processes also revealed that these polychaetes are free from pathogens. Standard Procedures for Culture of SPF Polychaetes In order to ensure stable production of polychaetes, it is necessary to understand the biology and culture requirements. The basic culture procedure, developed by many authors, involves the following steps. Polychaetes are collected from selected, pre-determined locations in the wild by hand-picking, followed by screening for pathogen-free status before being introduced into culture systems. Screened specimens are then brought to the laboratory / hatchery and kept under optimum conditions (Grassle and Grassle 1976, Poltana et al. 2007). Water quality parameters, particularly temperature, salinity and turbidity should be maintained in the same conditions as in the sampling environment. The worms may then be reared in aerated tanks at room temperature with salinity at 30-32 ppt. The worms are added to a polyethylene trough and are segregated. Healthy, active worms are sorted from the batch and released in the brood-stock tanks that have been set up prior to the sorting process (Figure 4). Adult worms are fed once daily with 1 mm pellets of a commercially available diet (Royal Dragon Vannamei Prawn Feed, Sheng Long Bio Tech India, Pvt. Ltd.). Any uneaten feed is captured and collected from the outlet pipe. Once they have settled, adults do not take much time to exhibit signs of breeding as they have already reached sexual maturity. When the signs of maturation are noticed, they are segregated out to a separate spawning and hatching unit. For broodstock maintenance, cement tanks are preferred. Mature females display a green anterior end, while the males’ anterior ends are white. Suitable males and females are selected and released in the spawning unit at the ratio of 1:2 (i.e. 1 male to 2 females). In certain cases, 1:3 ratios are also used, but in our facilities a 1:2 ratio is maintained. The spawning unit is typically comprised of FIGURE 2. Adult polychaetes collected from Agatti Island, Lakshadweep Archipelago. FIGURE 3. Captive raised polychaete juveniles in the NBFGR project site. (CONTINUED ON PAGE 36)
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