Aims: To evaluate the quality of fresh and whole Whitemouth croaker sold in a fish market through quantification of histamine-forming bacteria, determination of muscle histamine content and analysis of the microbiological profile of Whitemouth croaker caught in different seasons.Methods and Results: Fresh whole commercialized Whitemouth croaker were collected in different seasons (summer and winter). The histamine content was detected by HPLC-DAD. The histamine concentration ranged from 258.52 to 604.62 mg kg-1 in the Whitemouth croaker samples. The number of copies of histidine decarboxylase (hdc) oligonucleotides of gram-negative bacteria and the bacteria Morganella morganii and Enterobacter aerogenes were quantified by means of the polymerase chain reaction (qPCR). All samples were positive for the tested oligonucleotide groups, with copy numbers of the hdc oligonucleotides ranging from 4.67 to 12.01 log10g-1 in the samples. In addition, the 16S rRNA gene was amplified from six fresh Whitemouth croaker to comparatively explore the bacterial communities collected in the different seasonalities. It was observed that the phylum Proteobacteria was the most abundant, being the family Moraxellaceae more prevalent in Whitemouth croaker collected in the summer, whereas the Pseudomonadaceae was more present in the winter.Conclusions: This study showed that commercialized fresh Whitemouth croaker can be a source of food poisoning for the consumer. Histamine formation is associated with poor hygiene practices. Improvements in handling and processing are needed to minimize the prevalence of histamine-producing bacteria.Significance and Impact of the study. Histamine formation is associated with deteriorating microbiota and the cooling temperature of these fish. The high concentration of histamine strongly suggests the urgent need to improve quality control systems and temperature control throughout the production chain.