Cocconeis Ehrenberg assemblage (Bacillariophyceae) from Napuka Atoll (Tuamotu Archipelago, South Pacific) with descriptions of two new taxa

摘要

A 2012 survey of Napuka Atoll (north of the Tuamotu Archipelago, South Pacific Ocean) focused on marine benthic diatoms. Possibly due to its isolation, Napuka hosts several rare or poorly known Achnanthales. Although some Cocconeis taxa are identical to those found in high islands of the same area, several others have restricted distributions, being largely present in the Tuamotu Archipelago, particularly at Napuka, i.e., Cocconeis frustrationis sp. nov., Cocconeis tuamotuana sp. nov. and Cocconeis napukensis Riaux-Gobin et al. At least 10 Cocconeis taxa are present at Napuka with C. napukensis being particularly abundant in one sample but rare elsewhere. A comparison of the new taxa with allied species is presented.