Abstract

A total of 109 specimens of pelagic polychaetes belonging to 12 species in four families was collected using an Isaacs Kids Midwater Trawl (IKMT) during the Cimar 5 and Cimar 6 cruises in the SE Pacific Ocean off the Chilean coast as well as Easter I., San Felix I., San Ambrosio I. and the Juan Fernandez Archipelago. The species Torrea pelagica, Vanadis crystallina, V. formosa, V. longissima, V. minuta, Watelio gravieri, Lopadorhynchus uncinatus, Pelagobia longicirrata, Enapteris euchaeta, Tomopteris carpenterii, T. septentrionalis and Drieschia nans were identified from the complete set of plankton samples analysed. All the taxa have a cosmopolitan distribution with the exception of two species, Torrea pelagica and Drieschia nans, which are endemic to the South Pacific Ocean. Six species of Alciopidae (50% of abundance), three species of Tomopteridae (25%), two species of Lopadorhynchidae (16.7%) and one species of Polynoidae (8.3%) were identified in the samples analyzed. L. uncinatus, P. longicirrata, V. minuta, V. crystallina and W. gravieri are here reported for the first time in the SE Pacific off Chile and its' oceanic islands. Present results suggest the total number of species of pelagic polychaetes off the Chilean coast and its' oceanic islands is at least 19. We discuss the need for increasing quantitative plankton sampling to improve knowledge of the biology and ecology of the pelagic polychaetes of the SE Pacific Ocean, as well as to establish their relationships with the oceanic dynamics of the plankton.