Bibliographic Detail
Uwai, S., Kogame, K. & Masuda, M., 2002
Reference:
Uwai, S., Kogame, K. & Masuda, M. (2002). Conspecificity of Elachista nigra and Elachista orbicularis (Elachistaceae, Phaeophyceae). Phycological Research 50(3): 217-226.
Publication Date:
September 2002
Abstract:
A taxonomic study of two brown algal species, Elachista nigra Takamatsu and Elachista orbicularis (Ohta) Skinner (Elachistaceae), was performed on the basis of morphological observations of field-collected and laboratory cultured specimens from Japan (including their type localities) and molecular phylogenetic analyses. The two species had been distinguished by developmental patterns of paraphysis- and plurizoidangium-bearing erect filaments, such filaments of E. nigra developing from wide erect filaments and those of E. orbicularis developing directly from basal prostrate filaments. However, many specimens investigated in the present study showed forms intermediate between these two patterns. Molecular phylogenetic analyses (including five additional elachistacean species) based on the internal transcribed spacer (ITS)2 region of the nuclear ribosomal RNA (nrRNA) gene showed a close relationship between all samples of E. nigra and E. orbicularis, and that the developmental patterns of paraphysis- and plurizoidangium-bearing erect filaments were homoplasious. On the basis of these morphological and molecular data, E. orbicularis was reduced to synonymy with E. nigra. The ITS2 sequences of E. nigra were significantly different between samples from the Sea of Japan and those from the Pacific Ocean with several insertion/deletion and substitution mutations.
