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

Abstract

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.

Keywords:

• Cocconeis
• Napuka Atoll
• Tuamotu Archipelago
• South Pacific
• SEM

Acknowledgments

Jean Kape ‘Fasan Chong’, Remy Tchong and Marina Taki are warmly acknowledged for their hospitality and friendship during C. R.-G.’s stay at Napuka Atoll. René Galzin (CRIOBE-Moorea, French Polynesia) greatly helped with the logistics of the project. We acknowledge Oscar Romero (MARUM-Center for Marine Environmental Sciences, University of Bremen) for LM slide preparation, Dimitri and Yonko Gorand (C2M, Perpignan University) for their assistance with the SEM. Two anonymous reviewers are greatly acknowledged for their constructive remarks and the Editor, Eileen Cox, is thanked for her revision of the final draft.

Funding

Naturalia & Biologia and CNRS-USR 3278-Labex CORAIL funded the CORDIA projects.