RESUMO
The subterranean termite Heterotermes aureus is endemic to arid regions of southwestern USA and northern Mexico. Like other termites in the family Rhinotermitidae, it harbors a community of protists (Phylum Parabasalia) in its hindgut that aid in cellulose digestion. We investigated the hindgut community of H. aureus using light microscopy, single cell isolation, and high throughput amplicon sequencing. Here we describe four new parabasalid species from the classes Trichonymphea and Spirotrichonymphea. Three of the new species include Pseudotrichonympha aurea (Trichonymphea), Holomastigotoides aureus, and Holomastigotoides oxyrhynchus (Spirotrichonymphea). The fourth new species is a Spirotrichonympha-like protist for which we reinstate the genus Cononympha and describe under the name Cononympha aurea (Spirotrichonymphea). We also used high throughput amplicon sequencing with custom primers on DNA from fresh and ethanol preserved termites collected across the southwest USA and Mexico to investigate population-level differences in hindgut community composition. We report that the community is highly similar across populations: no additional parabasalid species were identified in any of the H. aureus specimens, but several specimens appeared to lack either C. aurea or H. oxyrhynchus.
Assuntos
Isópteros/parasitologia , Filogenia , Animais , Intestinos/parasitologia , México , Parabasalídeos/classificação , Parabasalídeos/citologia , Parabasalídeos/genética , Sudoeste dos Estados Unidos , Especificidade da Espécie , SimbioseRESUMO
Calonymphids are a group of multinucleate, multiflagellate protists belonging to the order Cristamonadida (Parabasalia) that are found exclusively in the hindgut of termites from the family Kalotermitidae. Despite their impressive morphological complexity and diversity, few species have been formally described and fewer still have been characterized at the molecular level. In this study, four novel species of calonymphids were isolated and characterized: Calonympha chia and Snyderella yamini spp. nov., from Neotermes castaneus and Calcaritermes nearcticus from Florida, USA, and Snyderella kirbyi and Snyderella swezyae, spp. nov., from Calcaritermes nigriceps and Cryptotermes cylindroceps from Colombia. Each of these species was distinguished from its congeners by residing in a distinct host and by differences at the molecular level. Phylogenetic analyses of small subunit (SSU) rDNA indicated that the genera Calonympha and Stephanonympha were probably not monophyletic, though the genus Snyderella, previously only represented by one sequence in molecular analyses, appeared with these new data to be monophyletic. This was in keeping with the traditional evolutionary view of the group in which the morphology of the genus Snyderella is considered to be derived, while that of the genus Stephanonympha is ancestral and therefore probably plesiomorphic.