Ctenocladus, Borzi, 1883

Darienko, Tatyana & Pröschold, Thomas, 2017, Toward a monograph of non-marine Ulvophyceae using an integrative approach (Molecular phylogeny and systematics of terrestrial Ulvophyceae II.), Phytotaxa 324 (1), pp. 1-41 : 20

Ctenocladus versus Lochmiopsis

The genus Ctenocladus described by Borzi (1883) is from a marine habitat. The characteristic morphological feature of the type species C. circinnatus is the one-sided branching of the filaments. Ctenocladus is so far known as a rare species. Only few records have been published ( Blinn & Stein 1970; Herbst & Castenholz 1994). Only one strain of C. circinnatus has been isolated and deposited in a public culture collection (CCMP 2158). However, this strain does not show the typical morphology of this genus in culture. In our study, this strain is almost identical in sequences with strains that were isolated from sandstone, and salt marshes at high carbonate concentrations (solonetz-solonchak). The latter habitat is typical for the genus Lochmiopsis , which was described by Woronichin & Popova (1929) from soda lakes in Siberia ( Russia). This genus was also recorded from solonetz-solonchak soils in different Asian deserts ( Novichkova-Ivanova 1984). Ruinen (1933) has demonstrated that L. sibirica has high phenotypic and ecological plasticity. She showed that material from the type locality and from California has similar morphology and ecology. Based on her findings, Smith (1950) transferred this genus Lochmiopsis as a later synonym of Ctenocladus , which is currently accepted by most phycologists ( Blinn & Stein 1970). Our investigations showed similarities and differences in morphology and ecology to those of both genera. Unfortunately, no authentic material of both genera are available in culture collections. Therefore, the taxonomic status remains unclear. However, as our study has demonstrated the type strain of Pseudopleurococcus printzii is closely related to the investigated strains mentioned above. As a consequence, we propose as a compromise the usage of the generic name Ctenocladus until material of both genera collected from type localities has been investigated.