Distribution of the genus Zonaria (Dictyotales: Phaeophyceae) in New Zealand, and description of Zonaria cryptica sp. nov from Stewart Island

The brown algal genus Zonaria (Dictyotales: Dictyotaceae) is widely distributed in temperate waters. Two species, Zonaria turneriana J.Agardh and Zonaria aureomarginata J.A. Phillips & W.A. Nelson have previously been recorded from mainland New Zealand, and a third species, Zonaria diesingiana, has been recorded from the Kermadec Islands. As part of an ongoing study of the order Dictyotales in New Zealand, we have identified an undescribed species of Zonaria present on Stewart Island in southern New Zealand. The new species, described here as Zonaria cryptica, is very similar in external morphology to Z. turneriana, also found on Stewart Island, but differs both genetically and anatomically from Z. turneriana and from other previously described species in the genus. We present a description of the new species based on morphological and anatomical observations, as well as on DNA sequence data from three plastid markers: psaA, psbA and rbcL. Our analysis also indicates the presence of some biogeographic structuring within Z. turneriana and Z. aureomarginata.