Diversity under a magnifier lens: The case of Typhlotanaidae in N Atlantic

Abstract Research focusing on ‘stout-bodied’ typhlotanaids collected from several sites around Iceland and adjacent northern seas has resulted in the description of 15 species new to science, as well as the creation of eight new genera. Typhlotanais eximius Hansen, 1913 was redescribed and transferred to a new genus, while Typhlotanais crassus and Peraeospinosus adipatus are transferred to the genus Larsenotanais. The morphological and the molecular data were combined to consolidate and confirm the validity of the results obtained from both approaches. The polyphyletic nature of Typhlotanaidae and its serious underestimation was emphasized. Molecular analysis revealed that the ’stout-bodied‘ Typhlotanaidae are monophyletic. Depth, temperature, and salinity were identified as the main environmental parameters determining the distribution of this group of Typhlotanaidae. Several species were clearly associated with shelf and upper bathyal of Iceland. The Greenland-Iceland-Faroe ridge is shown to be a distinct zoogeographical barrier for typhlotanaids inhabiting the deeper slope and abyssal around Iceland.