A non-pigmented, motile, Gram-negative bacterium, strain Z 271(T), was isolated from the surface of leaves of the seagrass Zostera marina which was collected in Troitza Bay (Sea of Japan, Pacific Ocean). The new isolate grew between 5 degrees C and 28 degrees C and was slightly halophilic, tolerating environments containing up to 5 % (w/v) NaCl. Strain Z 271(T) was able to degrade Tweens 20, 40 and 80 and partially degrade gelatin, but was unable to degrade casein. Phosphatidylethanolamine (36.9 %) and phosphatidylglycerol (63.1 %) were the predominant phospholipids. The major fatty acids included C(18 : 1)omega7c (43.7 %), C(16 : 1)omega7c (31.1 %) and C(16 : 0) (16.8 %). The main respiratory quinone was Q-8. The DNA-DNA relatedness value of strain Z 271(T) with Granulosicoccus antarcticus IMCC3135(T) was 35 %. The G+C content of the DNA of strain Z 271(T) was 60.2 mol%. On the basis of phenotypic and genotypic characteristics and 16S rRNA gene sequence analysis, strain Z 271(T) represents a novel species of the genus Granulosicoccus for which the name Granulosicoccus coccoides sp. nov. is proposed. The type strain is Z 271(T) (=KMM 6014(T)=CIP 109923(T)).