A new anaerobic rumen fungus was isolated
from the rumen fluid of a yellow cow (Bos
indicus). This fungus appears to be a previously
undescribed species of the genus Caecomyces, it
possessing uniflagellate zoospores, a spherical holdfast,
tubular sporangiophores and bulbous rhizoids.
This new fungus also features distinctive multisporangiate
thallus sympodially distributed on sporangiophores.
The fungus resembles Caecomyces communis
and C. equi in that it characterizes bulbous rhizoids
and uniflagellate zoospores but differs from C.
communis and C. equi in that it possesses multisporangiate
and sympodial sporangia. This new
fungus and Cyllamyces aberensis both reveal similar
morphology during early thallus development in
having a spherical holdfast, but they vary from
unbranched sporangiophores and additional bulbous
rhizoids. In addition, the molecular phylogenetic
analyses ITS1 (internal transcribed spacer 1) also
conform to the results of the morphological examinations
of Caecomyces. For the mentioned reasons,
this new species of fungus is described as Caecomyces
sympodialis sp. nov. The genera of Neocallimasticaceae
and species of Caecomyces are also keyed out.