The Hydrozoan Cladonema in California: A Possible Introduction from East Asia

Abstract

A hydrozoan of the genus Cladonema, new to the American west coast, is described from specimens taken from a display tank on the Berkeley campus of the University of California. Observations of its life history revealed it to be synonymous with Cladonema uchidai Hirai, 1958, known and described from northern Japan, although its distribution is probably much wider and includes coastal China and the USSR. The species is presumed to be present in San Francisco Bay, a point of introduction for many exotic species, although it is not yet known from the field.