A Gram-stain-negative, aerobic, motile, orange-pigmented, slightly halophilic, rod-shaped bacterium, designated strain JAMH 0132(T), was isolated from the trophosome of a tubeworm in Kagoshima Bay, Japan, and its taxonomic position was investigated using a polyphasic approach. The novel strain grew optimally at 28-30 °C and with about 2.0 % (w/v) NaCl. Chemotaxonomic analysis showed that Q-10 was the predominant respiratory quinone and that C(18 : 1)ω7c, C(16 : 0) 2-OH and C(16 : 0) were the major fatty acids. Sphingoglycolipid, phosphatidylethanolamine, diphosphatidylglycerol, phosphatidylglycerol and phosphatidylcholine were the major polar lipids. The genomic DNA G+C content was 60.1 mol%. Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain JAMH 0132(T) belonged to the family Sphingomonadaceae, within the class Alphaproteobacteria. The novel strain appeared most closely related to Sphingopyxis baekryungensis SW-150(T) (95.1 % 16S rRNA gene sequence similarity) and showed less sequence similarity with representatives of the genera Blastomonas, Sphingomonas, Sphingosinicella and Novosphingobium (<94.8 %). In having no detectable polyamine, strain JAMH 0132(T) differed from members of all genera currently in the family Sphingomonadaceae. On the basis of its phenotypic properties and phylogenetic distinctiveness, strain JAMH 0132(T) represents a novel species of a new genus in the family Sphingomonadaceae for which the name Parasphingopyxis lamellibrachiae gen. nov., sp. nov. is proposed. The type strain of Parasphingopyxis lamellibrachiae gen. nov., sp. nov. is JAMH 0132(T) (= JCM 15549(T) = NCIMB 14486(T)).