A Gram-stain-negative, strictly aerobic, rod- or oval-shaped, motile, non-spore-forming bacterium, designated strain CC-AMHB-3T, was isolated from coastal surface seawater off Hualien, Taiwan. The novel strain showed high pairwise 16S rRNA gene sequence similarities to
Ruegeria mobilis
NBRC 101030T (96.5 %),
Ruegeria scottomollicae
LMG 24367T (96.4 %),
Phaeobacter aquaemixtae
SSK6-1T (96.2 %),
Phaeobacter daeponensis
TF-218T (96.2 %),
Cribrihabitans marinus
CZ-AM5T (96.1 %) and other species of the family
Rhodobacteraceae
(≤95.9 %). However, strain CC-AMHB-3T formed a distinct phyletic lineage associated with
C. marinus
CZ-AM5T during phylogenetic analyses. The polar lipid profile of strain CC-AMHB-3T included major amounts of diphosphatidylglycerol, phosphatidylglycerol and phosphatidylcholine; moderate amounts of phosphatidylethanolamine, an unidentified aminolipid, an unidentified phospholipid and an unidentified lipid; and trace amounts of an unidentified lipid and an unidentified phospholipid, which was qualitatively almost in line with that of
C. marinus
CZ-AM5T but remarkably distinct as compared with the type species of the genera
Ruegeria
(
Ruegeria atlantica
JCM 21234T) and
Phaeobacter
(
Phaeobacter gallaeciensis
JCM 21319T). In line with the fatty acid profile of
C. marinus
CZ-AM5T, the major (>5 % of total) fatty acids of strain CC-AMHB-3T were C18 : 1ω7c and/or C18 : 1ω6c (summed feature 8), 11-methyl C18 : 1ω7c and C16 : 0. The DNA G+C content was 66.7 mol%. Ubiquinone-10 (Q-10) was the sole respiratory quinone. Thus, based on the results of the polyphasic study presented here, strain CC-AMHB-3T is considered to represent a novel species of the genus
Cribrihabitans
, for which the name Cribrihabitans neustonicus sp. nov. is proposed; the type strain is CC-AMHB-3T ( = JCM 19537T = BCRC 80695T). In addition, an emended description of the genus
Cribrihabitans
is also proposed.