Skibbe O.; Mora D.; Schimani K.; Abarca N.; Kusber W-H.; Huck V.; Zimmermann J.; Jahn R.
Willdenowia
The monoraphid diatom Cocconeis scutellum is considered to be the most common marine species of the genus Cocconeis. It has been reported from the littoral zones of marine and brackish waters worldwide. Described by Ehrenberg, it is the type of the name of the genus Cocconeis. Many varieties of C. scutellum have been described during the last two centuries; some have since been raised to specific rank. In recent years, high-resolution SEM and molecular methods have helped to better understand the boundaries among taxa and to study their geographic distribution. Despite several recent studies revising type material of other Cocconeis taxa by morphological and molecular characters, the type of the generic name has not yet been studied, nor have cultures from the type locality been established. We present molecular (rbcL, 18SV4) and morphological (LM, SEM) data for 18 Cocconeis strains that were isolated from the type locality in the southern Baltic Sea at Wismar, Germany, and match Ehrenberg's type material. Preserved material from one strain is designated as the epitype of C. scutellum. An emended species description is provided.
