Cookies Policy

This site uses cookies. By continuing to browse the site you are agreeing to our use of cookies.

I accept this policy

Find out more here

Problems in species delimitation

Brill’s MyBook program is exclusively available on BrillOnline Books and Journals. Students and scholars affiliated with an institution that has purchased a Brill E-Book on the BrillOnline platform automatically have access to the MyBook option for the title(s) acquired by the Library. Brill MyBook is a print-on-demand paperback copy which is sold at a favorably uniform low price.

Access this chapter

+ Tax (if applicable)

Chapter Summary

The genera Staurastrum and Staurodesmus are notorious for their problematic species delimitation and, consequently, difficult identification of those species. One of the main causes for this is the infrequent occurrence of sexual reproduction, a process of gene exchange resulting in reduced morphological variation. This phenomenon is not only characteristic of Staurastrum and Staurodesmus species but also of other desmid genera and many other groups of microalgae. Predominantly asexual reproduction in those unicellular organisms results in the formation of microspecies, mutually differing in only minor characteristics, just as in apomictically reproducing macrophytes. In addition to this genotypically based morphological variation, many Staurastrum and Staurodesmus species exhibit a remarkable phenotypic variation. Unfortunately, in most cases, the nature of morphological variability is unknown and not seldom one gets the impression that 'species' are interconnected by transitional forms rendering taxon delimitation rather arbitrary.

Keywords: morphological variation; phenotypic variation; sexual reproduction; Staurastrum species; Staurodesmus species delimitation



Can't access your account?
  • Tools

  • Add to Favorites
  • Printable version
  • Email this page
  • Recommend to your library

    You must fill out fields marked with: *

    Librarian details
    Your details
    Why are you recommending this title?
    Select reason:
    European Flora of the Desmid Genera Staurastrum and Staurodesmus — Recommend this title to your library
  • Export citations
  • Key

  • Full access
  • Open Access
  • Partial/No accessInformation