<i>Oricymba</i>(Cymbellales, Bacillariophyceae), a new cymbelloid genus and three new species from the Nepalese Himalaya

Abstract

Jüttner I., Krammer K., Van de Vijver B., Tuji A., Simkhada B., Gurung S., Sharma S., Sharma C. and Cox E.J. 2010. Oricymba (Cymbellales, Bacillariophyceae), a new cymbelloid genus and three new species from the Nepalese Himalaya. Phycologia 49: 407–423. DOI: 10.2216/09-77.1A new genus Oricymba is described with its type species based on Cymbella japonica Reichelt. In addition, three new species are described from the Nepalese Himalaya: O. subaequalis, O. latirotundata and O. subovalis. The new genus has slightly dorsiventral or almost symmetrical valves with polar raphe endings deflected to the dorsal side. It can be distinguished from other cymbelloid genera by two morphological characters. There is a ridge along the valve face: mantle junction, and areolae are slit-like and partially occluded by dentate projections. To date Oricymba has been found only in often nutrient-poor, freshwater habitats of the Indian subcontinent, Southeast Asia, Korea and Japan.