A yellow-pigmented, Gram-negative, aerobic bacterial strain comprising rod-shaped cells devoid of flagellar and gliding motility, designated strain A31(T), was isolated from a veined rapa whelk (Rapana venosa) collected from the South Sea, Republic of Korea. Results from 16S rRNA gene sequence analysis indicated that the isolate belonged to the family Flavobacteriaceae; the highest level of nucleotide sequence similarity (92.6 %) was observed with Tenacibaculum aestuarii KCTC 12569(T). The predominant cellular fatty acids were iso-C(15 : 1) G (24.2 %), iso-C(15 : 0) (20.1 %) and iso-C(17 : 0) 3-OH (11.2 %). Flexirubin-type pigments were absent. The major isoprenoid quinone was MK-6. The DNA G+C content was 31.7 mol%. Data from a polyphasic taxonomic study suggested that the isolate represents a novel species in a new genus of the family Flavobacteriaceae, for which the name Maritimimonas rapanae gen. nov., sp. nov. is proposed. The type strain of Maritimimonas rapanae is A31(T) (=KCTC 22186(T) =JCM 15075(T)).