Teleplanic pelagosphera larvae of sipunculans have been found throughout the tropical epipelagic waters of the Pacific and Indian Oceans. Evidence for their widespread occurrence is based on plankton samples from 849 locations. Among 22 tropical forms distinguished and described, 9
were encountered in the eastern Pacific (east of 140°W), 13 in the central Pacific, 8 in the west Pacific, and 11 in the tropical Indian Ocean. Four of the 13 central Pacific larval forms also occur in the eastern portion of the east tropical Pacific. Sixty-nine percent of the 13 central
Pacific larval forms were also to be found in the west Pacific and Indian Oceans. The number of central Pacific forms of pelagosphera are equal to 65% of the 20 adult shoal water species known to exist there. Among the 22 larval forms described, four were found to range throughout the tropical
Pacific and Indian Oceans including the east Pacific; three additional pelagospheras were widely distributed throughout the Indo-Pacific as far east as the Polynesian Islands. The evidence suggests that by their dispersal, larval sipunculans play an important biogeographic and evolutionary
role, but until a correspondence is established between larval forms and adult species, only tentative conclusions are possible.
The Bulletin of Marine Science is dedicated to the dissemination of high quality research from the world's oceans. All aspects of marine science are treated by the Bulletin of Marine Science, including papers in marine biology, biological oceanography, fisheries, marine affairs, applied marine physics, marine geology and geophysics, marine and atmospheric chemistry, and meteorology and physical oceanography.