Aquaculture has long been promoted by development institutions in Bangladesh on the understanding that it can alleviate poverty. Most of this attention has focused on forms of the activity commonly referred to as ‘small-scale’. This article draws on concepts from the literature on agricultural growth and elaborates a typology of aquaculture based on relations of production which suggests that, in Bangladesh, quasi-capitalist forms of aquaculture may possess greater potential to reduce poverty and enhance food security than the quasi-peasant modes of production generally assumed to do so. The implications of this conclusion are explored.