An opening and closing net system is described in which 1 m2 and 8 m2 rectangular trawls are combined in the same framework; details of the acoustic telemetering and release equipment are included. A brief account of the application of the rectangular system to larger and to more specialized trawls is given.

During the autumn of 1965 a detailed study was carried out by members of the National Institute of Oceanography and Scripps Institution of Oceanography into the vertical distribution of the micronekton, plankton and sonic scattering layers in the upper 1000 m at a position off Fuerteventura in the Canary Islands. This is one of a number of similar papers by various authors on the vertical distribution of the animal groups sampled (Angel, 1969; Clarke, 1969). A background to the investigation, including the hydrology of the area studied, has been given in an introductory paper by Currie, Boden & Kampa (1969).

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The identity of mammalian caregivers, the types of care each may provide to young, and the developmental, ecological, and social factors that influence the amount and distribution of care are discussed. Care is distinguished from use and abuse in terms of the impact on the survival of young. Some effects of the failure to allow for adequate maternal care are described, and various management strategies to promote adequate and appropriate care behaviors are identified.

The difficulty of keeping planktonic organisms alive in captivity has greatly hindered experimental studies of their physiology and behaviour. This has especially been the case with the plankton of the deep sea. Up to the present our studies of these organisms have been largely morphological and distributional and it is clear that to learn more about their ecological relationships we must find means of keeping them alive to study their metabolism and behaviour experimentally. With this end in view attempts have been made to keep some oceanic plankton animals alive in the laboratory on board ship and ashore.