9402011 Park Early researchers suggested that bathypelagic copepods have extremely widespread distributions, which was generally attributed to the relatively stable physical environment at bathypelagic depths. However, recent research by Park found that species of the bathypelagic copepod genus, Paraeuchaeta display highly variable ranges of geographic distribution. The geographic patterns displayed by the species seemed to reflect their food requirement and the availability of food in their habitats. The dominant species in the eutrophic waters were found to be endemics and the rare species generally had wider ranges of distribution. This project will study additional calanoid taxa inhabiting different depth ranges to see how the geographic patterns of calanoids vary with depth and whether the geographic patterns of the meso- and epipelagic calanoids are similar to those of Paraeuchaeta. The meso- and epipelagic carnivorous copepod genera, Heterorhabdus and Euchaeta were selected for the study so that carnivorous taxa from three different depth zones can be compared. Samples to be used for the study will be those collected from many different parts of the world's oceans and presently available mainly at Scripps Institution of Oceanography. Additional samples will be obtained, particularly for the Atlantic and Indian Oceans, from several other institutions. This study will follow the same procedures as employed in the study of Paraeuchaeta, asking the same questions: 1) How many species are there in each taxon selected? 2) How abundant is each species? 3) How widely distributed is each species? 4) How are the species related morphologically or distributionally to one another? By answering these questions, the study will accomplish two major objectives: 1) to clarify the taxonomy of the selected taxa by defining each species with adequate diagnoses, and 2) to define the biogeography of epi- and mesopelagic carnivorous genera based on established taxonomy and quantitative distribution data. The findings of this study, together with those already obtained with the bathypelagic Paraeuchaeta, are expected to help understand the global biogeography of carnivorous calanoids. ***
