Meroplankton in Jørgen Brønlund Fjord, North Greenland

Abstract

Meroplanktonic larvae of at least 42 species of bottom invertebrates in Jørgen Brønlund Fjord, North Greenland (82°10'N, 30°30'W) are described with respect to species identification, occurrence, reproduction, development, growth, settlement, and relations to depth, light, hydrography, and primary production. A few Holoplankters and some "pseudoplanktonic" nematodes are included. The occurrence of

such a large number of species with pelagic larvae does not invalidate "Thorson's rule" of 1950, stating that the number of species having pelagic larval development decreases, as one moves from the equator to the pole, but it does lead to a less strict interpretation of it. Several species have lecithotrophic pelagic development. The short period of primary production, however meager, seems vital to many of the

planktotrophic larvae, in promoting growth and settling, although the spawning of many species is not strictly linked to this period. Larvae of Hiatella striata (Fleuriau) seem able to live in the plankton for a year, even surviving the long, dark winter.