A novel bacterium, designated as strain PR12, was isolated from intestine of red swamp crayfish (Procambarus clarkii), which appeared as creamy white colonies on TSA plates. Growth occurred at temperatures of 4-37 °C (28-30 °C optimal), pH of 6.0-9.0 (7.0-8.5 optimal), and with 0-4.0% (w/v) NaCl (0-1.5% optimal). The cells were Gram-stain-negative, rod-shaped, non-motile, aerobic, oxidase- and catalase-positive, and chemoorganotrophic. Phylogenetic analysis based on 16S rRNA gene sequences showed that strain PR12 was related to members of the genus Comamonas and shared the highest sequence similarities with Comamonas koreensis KCTC 12005 (99.0%), Comamonas sediminis S3 (98.8%), and Comamonas piscis CN1 (98.0%). Whole genome size of PR12 was 5,111,300 bp and DNA G + C content was 63.5%. The major cellular fatty acids (> 10%) were C, C cyclo, summed features 3 (Cω6c and/or Cω7c) and summed features 8 (Cω6c and/or Cω7c). The major respiratory quinone was Q-8 and the major polar lipids contained diphosphatidylglycerol (DPG), phosphatidylglycerol (PG) and phosphatidylethanolamine (PE). Based on the digital DNA-DNA hybridization, phylogenetic analysis, average nucleotide identity, average aminoacid identity as well as biochemical characteristics, strain PR12 was clearly distinguishable from all recognized type strains of the genus Comamonas and represents a novel species, for which the name Comamonas squillarum sp. nov. is proposed. The type strain is PR12 (= MCCC 1K08379 = JCM 35896).