New slime mold subspecies identified

Dmytro (Dmitry) Leontyev traveled from the Ukraine to spend the 2013-14 academic year studying slime molds at the University of Arkansas as a Senior Fulbright Scholar in the department of biological sciences.

Leontyev is an associate professor in the department of biotechnology of Kharkiv State Zooveterinary Academy. Steve Stephenson, a research professor on biological sciences at the U of A, is hosting Leontyev, who was accompanied to the United States by his wife Stacy.

Leontyev is carrying out a research project that will develop a better understanding of the evolutionary relationships within the myxomycetes, a group of fungus-like organisms commonly associated with decaying plant material in all types of terrestrial ecosystems.

Although evolutionary relationships have been worked out for most major groups of organisms, this is not the case for the myxomycetes, which remain seriously understudied. The primary focus of Leontyev's project is on three families of myxomycetes: the Reticulariaceae, Cribrariaceae and Stemonitidaceae.

One member of the Reticulariaceae is the relatively well-known genus Tubifera, which contains the widespread and typically rather common species Tubifera ferruginosa. In 2005, Leontyev proposed that this species as traditionally recognized actually consists of a complex of cryptic species, and since then he has described three new species and one subspecies that can be distinguished from T. ferruginosa on the basis of morphological and molecular data.

During the first three months Leontyev has been at the U of A he has studied the large series of specimens of members of the genus Tubifera available in the myxomycete herbarium at the university, which holds one of the largest collections of these organisms in the world. Preliminary results based on molecular data seem to indicate that the 'true' Tubifera ferruginosa is represented in the Americas by several cryptic forms that are likely to be recognized as new subspecies.

In addition, a cluster of several closely related but apparently distinct new species has been found to exist in the American material. These still require more detailed morphological investigation. Studies of Tubifera bombarda, a second species of Tubifera restricted largely or completely to tropical regions of the world—and thus not found in Arkansas—suggest that it is distinct enough to be placed in its own genus. Interestingly, several specimens of what was identified as Tubifera bombarda when collected in New South Wales and Tasmania in Australia appear to represent a species new to science.

Provided by University of Arkansas