Description of new vessel hull fouling diatom Olifantiella (Naviculales, Bacillariophyceae) from the northwest temperate Pacific region

Abstract

Two elusive naviculoid diatoms with stigma-like structures on their valve face were observed on the hull of the R/V Onnuri from the Korea Institute of Ocean Science & Technology (KIOST) in South Korea. Under a scanning electron microscope,the morphological features, namely the buciniportula and the internal marginal chamber, were matched to the genus Olifantiella, which was recently described in tropical regions. Of these two Korean Olifantiella species, one is new to science and named as Olifantiella onnuria sp. nov., which can be distinguished from other Olifantiella species by an internally raised bean-like double processes and external T-shaped terminal raphe endings. These morphological features of O. onnuria resemble those of the genus Labellicula, however, the presence of an internal marginal chamber does not match the genus concept of Labellicula. The other Korean Olifantiella species is identical to O. muscatinei by the occluded macroareola on the valve face. These occurrences of two Olifantiella species are the first records from a temperate Pacific region and their presence on a ship’s surface indicate that Olifantiella spp. may be widely distributed globally despite their periphytic habit.