<![CDATA[Perna perna is an ecologically and nutritionally important bivalve that can accumulate microorganisms and reflect the environmental conditions of coastal ecosystems. This study evaluated the biochemical composition, microbial contamination, and growth-related characteristics of P. perna collected from two contrasting coastal sites, Al-Hami and Sharma, along the Gulf of Aden, Yemen. A total of 240 mussels were collected monthly from December 2022 to March 2023, with 30 individuals sampled from each site per month. Proximate composition was determined using standard analytical methods, while microbiological quality was assessed by measuring total bacterial counts, coliforms, and Escherichia coli, with Salmonella spp. examined as a major foodborne pathogen. Significant differences between sites were observed in several biochemical and microbiological parameters. Moisture content was significantly higher at Sharma (81.99 ± 4.60%) than at Al-Hami (70.26 ± 1.11%; p = 0.008), whereas protein content was relatively high at both sites. Microbiological analyses revealed substantially higher coliform contamination in seawater at Al-Hami (125.00 ± 12.50 CFU/100 mL) than at Sharma (1.67 ± 0.30 CFU/100 mL; p < 0.001). Similarly, E. coli counts in mussel tissues were significantly higher at Al-Hami (1.75 ± 0.21 CFU/g) than at Sharma (0.375 ± 0.08 CFU/g; p = 0.003). No Salmonella spp. were detected in any of the examined mussel samples. Monthly variation in microbial and biochemical parameters was generally limited, with most differences not reaching statistical significance. Overall, the findings demonstrate clear spatial differences in microbial contamination and biochemical composition between the two coastal sites and support the potential use of P. perna as a bioindicator of coastal environmental quality. The relatively high protein content and absence of detectable Salmonella further highlight the nutritional importance and microbiological status of this species within the conditions investigated.]]>
