An improved opening and closing net for sampling mesozooplankton and fish larvae is described. The device is based on a design by Bé (1962) and can be easily operated. Its five nets (0.25 m2 mouth opening) are sequentially opened and closed by shipboard command through a one-conductor cable. The multiple net equipped with a sensor for continuously recording depth was tested for oblique and vertical tows to a maximum depth of 1850 m, and it proved very reliable. Some contamination of closed nets is indicated. However, the mean percentage of contamination calculated for fish larvae and different groups of invertebrates did not exceed 2.8%.