Two low-maintenance culture systems for small pelagic marine animals

Abstract

Two simple tank designs are described and a list of the approximately 65 species of planktonic marine and estuarine organisms, mainly fish larvae and copepods, that have been reared or cultured in them is given. The first tank is a single-pass, flow-through version of the well-known false-bottom, or sub-sand filter system. The material used to cover the nylon-mesh bottom is either carbon sand or polyurethane foam. The second tank, called a “hoist-transfer tank”, has a smooth bottom sloping to a central drain. It is also operated on a single-pass, flow-through basis, the cultured organisms being retained by means of a submerged cartridge filter. It is capable of being physically raised or lowered by a winch. Before microfauna on the walls or bottom of a culture tank begins to significantly inhibit reproduction and growth of the organisms being cultured, the tank volume is transferred to a similar clean tank. Transfer is done by connecting a tube between the drains of the dirty and clean tanks and lifting the former relative to the latter. Both tank types receive a twice-daily, automatically dispensed suspension of phytoplankton food.