Two species of dictyostelid cellular slime molds from Alaska

Abstract

In sampling soils to survey dictyostelid cellular slime molds in Alaska we encountered two groups of isolates that have morphologies that differ from any previously described species within their group. We sequenced the nuclear small subunit ribosomal RNA gene (SSU rDNA) of selected isolates from the two groups and found sequences from both groups to be distinct from all previously described dictyostelid sequences. Phylogenetic analyses place one novel species in dictyostelid Group 2 and the other in Group 4 (Schaap et al. 2006). In this paper we formally describe as new these two species of cellular slime molds, Dictyostelium ammophilum sp. nov. and Dictyostelium boreale sp. nov., based on the combination of morphological and molecular characters.

• Alaska
• cellular slime molds
• molecular data
• morphology
• taxonomy

We thank these people for assisting in the collection of sample material that provided the basis for this study: Bess Morrison, Woody Woodgate, Rod Seppelt, Hal Burdsall and Luke Bruner. This research was sponsored in part by NPS research grants (PX9830–92–385, PX9830–93–062, PX9830–0–451, PX9830–0–472 and PX9830–0–512) to GL, NSF PBI Grant DB0316284 (Co-PI JC), by a grant from the Leverhulme Trust to SB and a postdoctoral fellowship from the Spanish Ministry of Science to MR (2007–0027). We also thank the many individuals of the National Park Service who provided great intangible support and thank especially Mats Thulin (Systematic Biology department, Uppsala University, Sweden) for help with translating the species diagnoses into Latin. We are particularly grateful to Steve Stephenson for encouraging our interest in slime molds of Alaska and supporting our opportunity to conduct this research and to Shepherd University for providing logistical support to JL.