There is a yet uncovered multitude of species to be found among Western Australian Onychophora. Kumbadjena, one of the two genera that reside in this region, has been previously suggested to house an extensive species complex. Morphology alone has not been able to elucidate the diversity in this genus and has instead muddled species delineations. Topologies and species delimitation analyses resulting from the sequences of two mitochondrial ribosomal markers (12S rRNA and 16S rRNA), one nuclear ribosomal marker (18S rRNA), and one mitochondrial protein-coding gene (cytochrome c oxidase subunit I) are indicative of several undescribed species. Fixed diagnostic nucleotide changes in the highly conserved sequences of 18S rRNA warrant distinction of three new species of Kumbadjena: K. toolbrunupensis, sp. nov., K. karricola, sp. nov., and K. extrema, sp. nov. The geographic distributions of the proposed species suggest that Kumbadjena is another example of short-range endemism, a common occurrence in the flora and fauna of the region. The extensive biodiversity and endemism in the region necessitates conservation to preserve the species and processes that promote speciation harboured by Western Australia.

Genomic data for priapulans are limited to a single species, restricting broad comparative analyses, and thorough interrogation of questions spanning phylogenomics, ecdysozoan physiology, and development. To help fill this void, we present here a high-quality priapulan genome for the meiofaunal species Tubiluchus corallicola. Our assembly combines Nanopore and Illumina sequencing technologies, and makes use of a whole genome amplification, to generate enough DNA to sequence this small meiofaunal species. We generated a moderately contiguous assembly (2547 scaffolds), with a high level of completeness (Metazoan BUSCOs n = 954, single copy complete = 89.6%, duplicated = 3.9%, fragmented = 3.5%, missing = 3.0%). We then screened the genome for homologs of the Halloween genes, key genes implicated in the ecdysis (moulting) pathway of arthropods, recovering a putative homolog of shadow. The presence of a shadow orthologue in two priapulan genomes suggests that the Halloween genes may not have evolved in a stepwise manner in Panarthropoda, as previously thought, but may have a deeper origin at the base of Ecdysozoa.

Genome assemblies are growing at an exponential rate and have proved indispensable for studying evolution but effort has been biased toward vertebrates and arthropods with particular focus on insects. Onychophora or velvet worms are an ancient group of cryptic, soil dwelling worms noted for their unique mode of prey capture, biogeographic patterns, and diversity of reproductive strategies. They constitute a poorly understood phylum of exclusively terrestrial animals that is sister group to arthropods. Due to this phylogenetic position, they are crucial in understanding the origin of the largest phylum of animals. Despite their significance, there is a paucity of genomic resources for the phylum with only one highly fragmented and incomplete genome publicly available. Initial attempts at sequencing an onychophoran genome proved difficult due to their large genome size and high repeat content. However, leveraging recent advances in long read sequencing technology, we present here the first annotated draft genome for the phylum. With a total size of 5.6Gb, the gigantism of the Epiperipatus broadwayi genome arises from having high repeat content, intron size inflation, and extensive gene family expansion. Additionally, we report a previously unknown diversity of onychophoran hemocyanins that suggests the diversification of copper-mediated oxygen carriers occurred independently in Onychophora­­ after its split from Arthropoda, parallel to the independent diversification of hemocyanins in each of the main arthropod lineages.

Symbion americanus is a microscopic marine invertebrate in the phylum Cycliophora that lives as an ectocommensal on the mouthparts of the American lobster, Homarus americanus. Previous phylogeographic work on S. americanus identified three lineages corresponding to one described and two potential new species, along with evidence of sympatry. But these studies did not explore whether individuals of S. americanus from different genetic lineages segregate onto different host mouthparts. The present study examines the population structure and microhabitat of 196 individuals of S. americanus from lobsters from five North American localities (from Newfoundland, Canada, to Boston, MA) collected between June and September 2019. Specimens were sequenced at two mitochondrial DNA (mtDNA) markers, a 487 bp fragment of cytochrome c oxidase subunit I (COI) and a 481 bp fragment of 16S rRNA. Phylogenetic analyses recover three distinct lineages of Symbion americanus, corroborating previous studies. Population genetic analyses of individuals belonging to the C and G lineages show clear population structure at the level of host mouthparts. Microhabitat data suggest the segregation of different genetic lineages in S. americanus onto different host mouthparts, perhaps indicating the role of spatial niche partitioning in the incipient speciation of S. americanus.