Diversity and distribution patterns of deep-sea polychaetes (Annelida) in the tropical Atlantic

Abstract

The main focus of the thesis is about polychaetes from the Ve¬ma-Fracture Zone (VFZ) and the Puerto Rico Trench (PRT). The general macrofaunal composition in this area is analysed in Chapter 2. Di¬versity and distribution of all polychaete families, as well as spionid and poly¬noid species along the VFZ were investigated with classical morphology, to test a connection between the eastern and western abyssal across the Mid-At¬lantic Ridge (Chapter 3). Additionally, three spionid genera (Chapter 4 and 5) and one polynoid genus (Chapter 6) were analysed with molecular methods. Next to the diversity and distribution ranges of species in the tropical Atlantic and discrepancies between morphological and molecular delimitated species, the spi¬onid genus Laonice was analysed with available data from other oceanic areas (Chapter 4). Comparable studies were conducted with Prionospio and Aurospio species, but a potential pan-oceanic distribution was tested with a large dataset from Prionospio and Aurospio specimens from the central Pacific (Chapter 5). The last chapter is dealing with the diversity and distribution of the hitherto monotypic genus Bathypolaria, whereby based on the high abundance of this polynoid genus in the hadal PRT the vertical dispersal potential was additionally studied (Chapter 6).