The History and State of the Study of Medusae and Hydroids

Abstract

SynopsisThe growth of knowledge of medusae and hydroids is attributable to the labours, from the beginning of the eighteenth century onwards, of numerous naturalists and zoologists, amateur and professional, to whom we are indebted for studies of the structure, biology and systematics of these animals, and to the many investigations at sea, by geographical and oceanographic expeditions and by fisheries and other institutions, from which we have derived knowledge of the occurrence and distribution of the species in the seas and oceans. The study of invertebrates gained great impetus in the latter part of the eighteenth century and in the nineteenth century with the accumulating observations and material collected, but only gradually were the true affinities and proper classification of the invertebrate groups recognised. The major advances in the systematic study of medusae and hydroids were the recognition of the true relationships between them and of their distinction from other coelenterates and the full understanding of their reproductive and other structures. Knowledge of the rich variety of species and their world distribution has been gained especially by oceanic expeditions and fisheries investigations. The importance of medusae as ‘indicators’ of hydrographic conditions is well recognised.