Littorina saxatilis “crab” ecotype photograph and Hi-C map. A) Photograph of Littorina saxatilis “crab” ecotype on Swedish shore (Photo: Patrik Larsson). B) Hi-C contact map of the new Littorina saxatilis assembly after manual curation, visualized in HiGlass. Chromosomes are arranged in size order from left to right and top to bottom.