World Aquaculture September 2018

WWW.WA S.ORG • WORLD AQUACULTURE • SEP TEMBER 2018 43 was initiated in Cox’s Bazar in 2010 and then gradually expanded into the Satkhira region on a limited scale (Islam et al. 2015). Approximately 39 farms are currently in operation in coastal areas in the Satkhira district. The farms operate soft-shell crab production systems in which crabs are stocked individually in small perforat- ed plastic boxes (Shelley and Lovatelli 2011). Depending on production capacity, 30 farms can be categorized as small, eight as medium and one as a large farm (Fig. 2), holding ap- proximately 2,000-14,000, 33,000-200,000, and 600,000 plastic boxes, respectively, covering approximately 70-80 ha of coastal water bodies that were formerly used for shrimp farming. Most of these farms are owned by non-local afflu- ent business people and lands are leased for at least five years tenure and jointly operated because substantial investment and large-scale management are required (Rahman et al. 2017). The main water sources for the farms are seawater canals and rainfall. There are well-facilitated water inlet and outlet systems on soft-shell crab farms. A limited number of potential species are suitable for coastal crab aquaculture in Bangladesh. Presently the mud crab ( Scylla spp.) is recognized as a prime candidate species to replace black tiger shrimp ( Penaeus monodon ) for farming in coastal water bodies. These conditions suggest very strong potential for semi-intensive mud crab aquaculture development. Soft-shell crab production is widely envisioned as having excellent prospects to contribute to livelihoods of coastal community members by providing income from lucrative foreign markets. On-farmproductionprocess. Soft-shell crab farms are situated near sources of seed and other facilities, with affordable land, serviceable roads and communication services, and available labor. Farms typically purchase seed crabs from nearby depots C rab fisheries, aquaculture and trade have appeared as an opulent commercial venture, with global crab production of almost 1.3 million tons in 2015 (Hungria et al. 2017). Recently, soft-shell crab is one of the most desired forms for marketing because consumers consider the product to be a gastronomic delicacy (Perry et al. 2010, He 2015). The term soft-shell crab does not refer specifically to any particular crab species, but to the physiological state of any crab that has just undergone molting to replace their old hard exoskeleton with a new, slightly larger, hydrated and decalcified soft exoskeleton (Freeman and Perry 1985). During this short transitional stage, normally within the first hour, the term soft-shell crab is applicable (Freeman et al. 1987) and such crabs command value- added prices. They are considered a culinary delicacy with high market value, often ranging up to seven times the price of comparable hard-shell crabs (Wickins and Lee 2002, Cap Log Group 2012). The demand and price of soft-shell crabs are increasing in international markets (Tavares et al. 2017). Based on abundance and available technology, Scylla spp. are among only a few swimming crab species (Shelley and Lovatelli 2011) that are cultured and marketed internationally as soft-shell crabs (Kennedy and Cronin 2007). The production of soft-shell mud crabs (mostly S. serrata ) in coastal Bangladesh is a new addition to established fattening practices for hard-shell crab production (Rahman et al. 2017). The potential for soft-shell crab production and business development in Bangladesh is strong (Fig. 1). This article presents an overview of the current status of soft-shell crab culture in the country. Present Status of Soft-shell Crab Culture in Bangladesh The brackishwater and marine coastlines of Bangladesh are well suited for soft-shell crab production. The production of soft-shell crab Soft-Shell Crab Production in Coastal Bangladesh: Prospects, Challenges and Sustainability Md. Mojibar Rahman, Shahroz Mahean Haque, Abdul Wahab, Hillary Egna and Christopher Brown ( C O N T I N U E D O N P A G E 4 4 ) FIGURE 1. Contribution of different sources (approx. percent) to total crab exports from Bangladesh. FIGURE 2. The largest land-based soft-shell crab farm in Shyamnagor, Satkhira, Bangladesh (Photo: Md. Mojibar Rahman).