New host and symbiont marker genes from different stilbonematine nematodes, including the new genus Paralaxus

Sediment samples containing Stilbonematine nematodes were collected in the Caribbean Sea (Belize), the Western Atlantic Ocean (Florida and Bermuda), the Western and Central Pacific Ocean (Australia and Hawaii) as well as the North and Mediterranean Sea using cores or buckets. Nematodes were extracted by decantation, photographically vouchered and washed in 0.2 µm filtered seawater before fixation. DNA from single nematodes including their bacterial ectosymbionts was extracted and 2 × 100 bp paired-end reads were sequenced on an Illumina HiSeq3000 per specimen. Host 18S rRNA, cytochrome oxidase I (COI) and symbiont 16S rRNA gene sequences were extracted from draft metagenomic assemblies.