On seven undescribed leaf insect species revealed within the recent "Tree of Leaves" (Phasmatodea, Phylliidae).

With the recent advance in molecular phylogenetics focused on the leaf insects (Phasmatodea, Phylliidae), gaps in knowledge are beginning to be filled. Yet, shortcomings are also being highlighted, for instance, the unveiling of numerous undescribed phylliid species. Here, some of these taxa are described, including Phylliumiyadaonsp. nov. from Mindoro Island, Philippines; Phylliumsamarensesp. nov. from Samar Island, Philippines; Phylliumortizisp. nov. from Mindanao Island, Philippines; Pulchriphylliumheraclessp. nov. from Vietnam; Pulchriphylliumdelisleisp. nov. from South Kalimantan, Indonesia; and Pulchriphylliumbhaskaraisp. nov. from Java, Indonesia. Several additional specimens of these species together with a seventh species described herein, Pulchriphylliumanangusp. nov. from southwestern India, were incorporated into a newly constructed phylogenetic tree. Additionally, two taxa that were originally described as species, but in recent decades have been treated as subspecies, are elevated back to species status to reflect their unique morphology and geographic isolation, creating the following new combinations: Pulchriphylliumscythe (Gray, 1843) stat. rev., comb. nov. from Bangladesh and northeastern India, and Pulchriphylliumcrurifolium (Audinet-Serville, 1838) stat. rev., comb. nov. from the Seychelles islands. Lectotype specimens are also designated for Pulchriphylliumscythe (Gray, 1843) stat. rev., comb. nov. and Pulchriphylliumcrurifolium (Audinet-Serville, 1838) stat. rev., comb. nov. from original type material.

Complete mitochondrial genomes of June sucker and Utah sucker (Chasmistes liorus and Catostomus ardens).

The relationship between June sucker (Chasmistes liorus, Jordan, 1878) and Utah sucker (Catostomus ardens, Jordan & Gilbert, 1881) has been a matter of controversy since the mid 1900s. Chasmistes liorus is endemic to Utah Lake, UT and has a subterminal mouth adapted for pelagic feeding. Catostomus ardens is widely distributed throughout the Bonneville Basin and Upper Snake River Basin and has a ventral mouth adapted for benthic feeding. Chasmistes has been recognized as a separate ancient genus. Despite being morphologically distinct, no study has successfully identified residual genetic markers that separate these species. Of these studies, several have used a subset of mitochondrial genes, but no study has analyzed the complete mitochondrial genomes (mitogenomes) of these suckers (Pisces: Catostomidae). To further explore the genetic relationships between these species, we report the complete mitogenomes of Chasmistes liorus and Catostomus ardens. DNA was sequenced using an Illumina HiSeq 2500 system and mitogenomes were assembled and annotated using Geneious v. 2021.2 and MitoAnnotator, respectively. The mitogenomes of Chasmistes liorus and Catostomus ardens are both 16,623 bp and are ∼0.072% divergent. We examine the phylogenetic relationship between Chasmistes liorus and Catostomus ardens using 33 mitogenomes, representing 16 species, from Catostomidae. Our data suggest that Chasmistes liorus is sister to Catostomus ardens. Additional samples from multiple localities and/or cohorts of these species will allow us to better resolve the complicated phylogenetic relationships between these species.

Species boundaries in the messy middle-A genome-scale validation of species delimitation in a recently diverged lineage of coastal fog desert lichen fungi.

Species delimitation among closely related species is challenging because traditional phenotype-based approaches, for example, using morphology, ecological, or chemical characteristics, may not coincide with natural groupings. With the advent of high-throughput sequencing, it has become increasingly cost-effective to acquire genome-scale data which can resolve previously ambiguous species boundaries. As the availability of genome-scale data has increased, numerous species delimitation analyses, such as BPP and SNAPP+Bayes factor delimitation (BFD*), have been developed to delimit species boundaries. However, even empirical molecular species delimitation approaches can be biased by confounding evolutionary factors, for example, hybridization/introgression and incomplete lineage sorting, and computational limitations. Here, we investigate species boundaries and the potential for micro-endemism in a lineage of lichen-forming fungi, Niebla Rundel & Bowler, in the family Ramalinaceae by analyzing single-locus and genome-scale data consisting of (a) single-locus species delimitation analysis using ASAP, (b) maximum likelihood-based phylogenetic tree inference, (c) genome-scale species delimitation models, e.g., BPP and SNAPP+BFD, and (d) species validation using the genealogical divergence index (gdi). We specifically use these methods to cross-validate results between genome-scale and single-locus datasets, differently sampled subsets of genomic data and to control for population-level genetic divergence. Our species delimitation models tend to support more speciose groupings that were inconsistent with traditional taxonomy, supporting a hypothesis of micro-endemism, which may include morphologically cryptic species. However, the models did not converge on robust, consistent species delimitations. While the results of our analysis are somewhat ambiguous in terms of species boundaries, they provide a valuable perspective on how to use these empirical species delimitation methods in a nonmodel system. This study thus highlights the challenges inherent in delimiting species, particularly in groups such as Niebla, with complex, relatively recent phylogeographic histories.