The importance of scanning electron microscopy (SEM) in taxonomy and morphology of Chironomidae (Diptera)

  • Andrzej Kownacki Institute of Nature Conservation Polish Academy of Sciences
  • Ewa Szarek-Gwiazda Institute of Nature Conservation Polish Academy of Sciences
  • Olga Woźnicka Department of Cell Biology and Imaging, Institute of Zoology, Faculty of Biology and Earth Sciences, Jagiellonian Univeristy, ul. Gronostajowa 9, 30-387 Kraków

Abstract

The paper reports on the value of scanning electron microscopy (SEM) in the taxonomy and morphology of Chironomidae. This method has been relatively rarely used in Chironomidae studies. Our studies suggest that the SEM method provides a lot of new information. For example, the plastron plate of the thoracic horn of Macropelopia nebulosa (Meigen) under light microscopy is visible as points, while under SEM we have found that it consists of a reticular structure with holes. By using SEM a more precise picture of the body structure of Chironomidae can be revealed. It allows researchers to explain inconsistencies in the existing descriptions of species. Another advantage of the SEM method is obtaining spatial images of the body and organs of Chironomidae. However, the SEM method also has some limitations. The main problem is dirt or debris (e.g. algae, mud, secretions, mucus, bacteria, etc.), which often settles on the external surface of structures, especially those which are uneven or covered with hair. The dirt should be removed after collection of chironomid material because if left in place it can become chemically fixed to various surfaces. It unnecessarily remains at the surface and final microscopic images may contain artifacts that obscure chironomid structures being investigated. In this way many details of the surface are thus unreadable. The results reported here indicate that SEM examination helps us to identify new morphological features and details that will facilitate the identification of species of Chironomidae and may help to clarify the function of various parts of the body. Fast development of electron microscope technique allows us to learn more about structure of different organisms.

Author Biography

Andrzej Kownacki, Institute of Nature Conservation Polish Academy of Sciences
al. Mickiewicza 33, 31-120 Krakow
Published
2015-06-30
Section
Articles