Wassey, N. | bioRxiv Science

bioRxiv2026

Morphogenomic description of Cranifera cranifera (Chitwood, 1932) Kloss, 1960 from captive Blaptica dubia Serville, 1838 cockroach

Nematodes of the superfamily Thelastomatoidea are found in the digestive system of various arthropods, feeding on their host microbiome. They are sometimes considered to be ecologically intermediate forms between free-living rhabditids and parasitic Spirurina, while phylogenetically they are nested within the latter. In addition to new morphological data on the male morphology, this manuscript presents the first nuclear genome assembly of a thelastomatid species, Cranifera cranifera, using long-read sequencing approach, making a total of three nuclear genomes available for superfamilyThelastomatoidea. The C. cranifera nuclear genome assembly presented here is 246 Mb long, consists of 7563 contigs, has an N50 of 43 kb and includes 94% of the BUSCO nematoda_odb12 genes. The mitochondrial genome is 24646 bases long, includes a complete set of protein coding, rRNA and tRNA genes, and a repetitive region 9731 bases long, which includes multiple copies of tRNA-Asn(gtt) and tRNA-Lys(ttt). The nuclear assembly also contained two sequence variants of the 28S rRNA gene, highlighting the presence of intragenomic variation within rRNA operon. The newly generated assemblies (nuclear and organelle) will add to a growing body of genomic resources for underrepresented and understudied animal parasitic nematodes from the Clade 3, enabling comprehensive studies in their phylogeny and trait evolution in the future.

zoology↗

bioRxiv2024

Soil biodiversity in the Atacama Desert shows distinct patterns at different diversity levels

Species diversity and distribution, in relation to how they interact with their environment is a major focus of ecological research. Particularly for soil ecosystems, information about geographical patterns of biota is scarce despite the pivotal role of soils as ecosystem service providers. The Atacama is the driest non-polar desert on earth: water is scarce, high salinity patches are frequent and water bodies have high concentrations of metals. It is believed that only specialized taxa can survive in this Desert. Accordingly, only some microbial life-forms and few plants, and vertebrates are present. Above ground invertebrates have been reported in the desert but its soils have not been comprehensively analyzed. By studying different areas in the Atacama, we aim to better understand resilience of soil organisms in times of global aridification. Nematodes are one of the most important groups of soil organisms in abundance and biodiversity. Here, we investigated diversity of soil nematodes at the genetic, taxonomic, community and life-cycle levels. We find distinct patterns and assemblages along the different habitats in the desert: dune systems, high altitude mountains, saline lakes, river valleys and fog oases. We also find that distribution of asexual taxa is more likely to occur at higher altitudes, and that the distribution of genera richness in the Atacama follows a latitudinal diversity gradient, as well as an increase with increasing precipitation. Our work shows that even under extreme environmental conditions stable, healthy soil communities can persist, but we see indicators of poor soil food webs.

ecology↗