The Supposed Resting Stage of Limnocnida Indica Annandale

Abstract

THE life-history of this fresh-water medusa has been a baffling problem since its discovery twenty years ago.1 The jelly-fish occurs in certain rivers flowing down the eastern slopes of the Western Ghats of the Bombay Presidency during definite seasons of the year (March to May). What happens to the species during the rest of the year has been more or less a mystery. From the fact that it occurs year after year in certain parts only of these rivers, it has been supposed that there is a fixed asexual hydroid stage in the life-cycle of the animal, which buds off medusae at the commencement of the hot weather.2 Although the medusae were kept under observation in the field, and a careful search for the hydroid stage made on more than one occasion, no clue to the mystery was obtained. Nearly eight years after the discovery of the jelly-fish, the late Dr. Annandale, as a result of further observations, recorded his opinion that the species “must have a fixed or resting stage in its life-history, perhaps with the structure of a minute hydroid, or more probably encysted in a form that would not be recognisable with our present knowledge”.3