The compact genome of a new Caenorhabditis species Caenorhabditis niphades n. sp., isolated from Niphades beetles

The first metazoan genome sequenced, that of Caenorhabditis elegans , impulse animal genome evolution studies. To date > 50 species from the genus Caenorhabditis have been sequenced, allowing research on genome variation. In the present study, we describe a new gonochoristic species, Caenorhabditis niphades n. sp., previously referred as C. sp. 36, isolated from adult weevils ( Niphades variegatus ), with whom they appear to be tightly associated during its life cycle. Along with a species description, we sequenced the genome of C. niphades n. sp. and produced a chromosome-level assembly. A genome comparison highlighted that C. niphades n. sp. has the smallest genome (59 Mbp) so far sequenced in the Elegans supergroup, despite of being closely related with the largest genome species, C. japonica. The compact genome of C. niphades n. sp. can serve as a key resource for comparative evolutionary studies of genome and gene number expansions in Caenorhabditis species.