The Stilbonematinae are a monophyletic group of marine nematodes that are characterized by a coat of thiotrophic bacterial symbionts. Among the ten known genera of the Stilbonematinae, the genus Gerlach 1956 had a problematic taxonomic history of synonymizations and indications of polyphyletic origin. Here we describe three new species of the genus, sp. nov., sp. nov. and sp. nov., using conventional light microscopy, interference contrast microscopy and SEM. We provide 18S rRNA gene sequences of all three species, together with new sequences for the genera and . Both our morphological analyses as well as our phylogenetic reconstructions corroborate the genus . In our phylogenetic analysis the three species of the genus form a distinct clade in the Stilbonematinae radiation and are clearly separated from the clade of the genus , which has previously been synonymized with . Surprisingly, in sp. nov. all females are intersexes exhibiting male sexual characters. Our extended dataset of Stilbonematinae 18S rRNA genes for the first time allows the identification of the different genera, e.g. in a barcoding approach. http://zoobank.org/urn:lsid:zoobank.org:pub:D37C3F5A-CF2B-40E6-8B09-3C72EEED60B0.

The Proterodiplostomidae Dubois, 1936 is a family of digeneans within the superfamily Diplostomoidea Poirier, 1886. Members of the family are distributed mostly in the tropics and subtropics, primarily in crocodilians, although some species are known from other reptiles. Despite their broad geographical distribution, the knowledge of proterodiplostomid diversity remains limited, mostly because a number of potential host species and regions of the world have not been sufficiently explored for these parasites. In this study, we use morphological and molecular data to describe four new genera ( gen. nov., gen. nov., gen. nov. and gen. nov.) and five new species ( sp. nov., sp. nov., sp. nov., sp. nov. and sp. nov.) of proterodiplostomids from crocodilians in Australia, South Africa and South America. gen. nov. has been established upon re-evaluation of the status of (Dubois, 1936) from caimans in Brazil using combined morphological and molecular evidence. Only a few previous studies provided DNA sequence data of proterodiplostomids. We generated partial 28S rDNA and cytochrome subunit (1) mtDNA for three previously undescribed proterodiplostomids collected from spp. in Australia and South Africa. The newly generated 28S sequences were used to examine phylogenetic affinities of these taxa. All three newly sequenced proterodiplostomid species appeared in the phylogenetic tree in a strongly supported monophyletic clade comprising exclusively parasites of .

Green algal species of spherical cell shape are generally considered to belong to the genus , which are mostly freshwater or terrestrial organisms. Phylogenetic studies have shown that this genus is polyphyletic and belongs to different classes. However, until now, only freshwater or terrestrial strains have been studied. Here we investigated 11 strains of 'marine' deposited in public culture collections, which we studied using an integrative approach. These strains were largely isolated from marine rock pools and brackish estuaries. SSU and ITS regions of the nuclear encoded ribosomal DNA were sequenced, ribosomal secondary structures were analysed and cell morphology, salinity tolerance and reproduction were examined. Our results showed that the marine strains are also of polyphyletic origin. Surprisingly, three marine isolates belong to according to the phylogenetic analyses, but showed a high phenotypic plasticity. Whereas these strains showed the typical morphology of under freshwater conditions, they increased the cell shape and formed cell packages under marine conditions. In contrast, the other investigated strains showed no changes after changing the media. Two of the investigated strains belong to the genus , and those remaining represent a new genus, .

Northern bog lemmings, () , are currently being assessed for protections under the U.S. Endangered Species Act. A major impediment to comprehensive evaluation is a deficiency of data towards understanding the biology of these rodents. Inherent rarity and scarce specimen sampling, despite a continent-wide distribution, has precluded our ability to implement modern methods for resolving taxonomy, evolutionary history, and investigating multiple other species traits. Here we use a maternally inherited locus (mitochondrial cytochrome b) and between 5,939 and 11,513 nuclear loci from reduced representation sequencing (ddRADseq) to investigate the evolutionary history of northern bog lemmings. We 1) qualify evidence based on morphological and early molecular studies for the genus assignment of , 2) test the validity of multiple sub-species designations, 3) provide spatial and temporal historical biogeographic perspectives, and 4) discuss how incomplete sampling might influence conservation efforts. Both mitochondrial and nuclear datasets exhibit deep divergence and paraphyly between two recognized species, the northern () and southern () bog lemmings. Based on mtDNA, the geographically isolated subspecies () was found to be divergent from all other specimens. The remainder of the species exhibited shallow intra-specific differentiation in mtDNA, however nuclear data supports genetic distinction consistent with four geographic subspecies. Recent coalescence of all northern bog lemmings (except for ) reflects divergence in multiple refugia through the last glacial cycle, including a well-known coastal center of endemism and multiple regions south of continental ice-sheets. Regional lineages across North America suggest strong latitudinal displacement with global climate change, coupled with isolation-reconnection dynamics. This taxon suffers from a lack of modern samples through most of its distribution, severely limiting interpretation of ongoing evolutionary processes, particularly in southern portions of the species' range. Limited voucher specimen sampling of vulnerable populations could aid in rigorous conservation decision-making.