Overview of the results. a) Photograph of B. similaris. b) GenomeScope k-mer profile plot for B. similaris, displaying observed k-mer frequency (bar plot), full model fitted by GenomeScope (black line). len, estimated genome size; uniq, the proportion of non-repetitive sequences; aa, homozygosity rate; ab, heterozygosity rate; kcov, mean k-mer coverage for heterozygous bases; err, error rates of the reads; dup, average rate of read duplications; k, k-mer size; p, ploidy. c) Hi-C contact map for B. similaris with chromosomal scaffolds (blue boxes). Darker red indicates higher contact density. d) Comparison of OMArk statistics for Panpulmonata snails. All data were sourced from OMArk web server. The shown species and accession numbers (in parentheses) are the following: Biomphalaria glabrata (BglaB1, UP001165740, and GCF_947242115.1), Biomphalaria pfeifferi (GCA_030265305.1), B. similaris (this study), Bulinus truncatus (GCA_021962125.1), C. unifasciata (UP000678393 and GCA_905116865.2), Elysia chlorotica (UP000271974 and GCA_003991915.1), Elysia crispate (GCA_033675545.1), Elysia marginata (GCA_019649035.1), Lymnaea stagnalis (GCA_964033795.1), Physella acuta (GCF_028476545.1), and Plakobranchus ocellatus (GCA_019648995.1).