One slightly beige-white pigmented, Gram-stain-negative, rod-shaped bacterium, strain I-STPP5b(T), was isolated from the trachea of a Gentoo penguin chick individual (Pygoscelin papua) investigated in Fildes Bay, Chilean Antarctic (62 degrees 12' S, 58 degrees 57' W). I-STPP5b(T) consists of a 3.4 Mb chromosome with a DNA G+C content of 44.4 mol%. Of the 3056 predicted genes, 1206 were annotated as hypothetical proteins and 51 were tRNAs. Phylogenetic analysis based on nearly full-length 16S rRNA gene sequences showed that the isolate shared a 16S rRNA gene sequence identity to the type strains of Psychrobacter phenylpyruvicus (98.8%), Psychrobacter arenosus and Psychrobacter pasteurii (both 98.3%), Psychrobacter piechaudii (98.2%) and Psychrobacter sanguinis (98.1%), but 16S rRNA gene sequence similarities to all other Psychrobacter species were <= 98.0%. Partial gyrB nucleotide and amino acid sequence similarities among strain STPP5b(T) and the next related type strains were all below 81.8 and 92.9%, respectively. DNA-DNA hybridisation (DDH) with P. phenylpyruvicus LMG 5372(T), P. arenosus DSM 15389(T) and P. sanguinis DSM 23635(T) also showed low values (all below 30%). The main cellular fatty acids of the strain were C-18:1 omega 9c and C-16:1 omega 7c and/or C-16:1 omega 6c. Based on phylogenetic, chemotaxonomic, genomic and phenotypic analyses we propose a new species of the genus Psychrobacter, with the name Psychrobacter pygoscelis sp. nov. and strain I-STPP5b(T) (=CIP 111410(T)=CCM 8799(T)=LMG 30301(T)) as type strain.