Brachyura larvae
Geographic and bathymetric distribution

Known abiotic factors that strongly affect spatial distribution patterns of planktonic organisms include temperature, salinity, dissolved oxygen, water currents, and depth. The individual or collective action of these and other environmental factors increases or limits the area of distribution for marine species, where those factors with the most significant variations are the ones that limit the area of occurrence (Vernberg and Vernberg, 1970; Melo, 1985).

Presently the study of geographic and bathymetric distributions of larval crustacean stages is still in its infancy and the words of Gardiner (1904) that "... in the present stage of knowledge any consideration of larval distribution is premature and must be inconclusive" still hold true today. The precise zoogeographical distribution of many crab species that occur in the South Atlantic is especially poorly known in eastern waters. Larvae of many Southeastern Atlantic species are unknown and only those that also occur in western areas are covered in this volume. Distributional data presented are mainly based on the occurrence of adults in the Southwest Atlantic, along the coast of Brazil, Uruguay and Argentina. The Brazilian coast is the most diverse with approximately three hundred crab species.