Pandora’s Box in the Deep Sea –Intraspecific Diversity Patterns and Distribution of Two Congeneric Scavenging Amphipods

Paralicella tenuipes Chevreux, 1908 and caperesca Shulenberger Barnard, 1976 are known as widely distributed deep-sea scavenging amphipods. Some recent studies based on genetic data indicated the presence of high intraspecific variation P. suggesting it is a species complex. Based published molecular from Pacific Indian oceans new material obtained North South Atlantic, we integrated knowledge distribution two nominal taxa. The study included analysis three genes (COI, 16S rRNA, 28S rRNA) revealed existence single Molecular Operational Taxonomic Unit (MOTU) within six different MOTUs forming . pattern recognized lineages varied with ( , MOTU 1 5 ) being distributed. There was evidence contemporary population connectivity expressed by share same COI haplotypes individuals very distant localities. At time no signal demographic changes observed studied time-calibrated phylogeny suggested emergence to be at Mesozoic/Cenozoic transition that may associated global ocean circulation deep sea water cooling.