The red swamp crayfish (Procambarus clarkii) was introduced from Japan to China in the 1920s. Crayfish are now widely distributed in almost all types of freshwater wetlands, including rice fields, ditches, swamps, lakes, and ponds in most provinces of China, owing to their multi-directional movement, rapid growth, adaptability to the environment, and relatively high fecundity. The delectable taste and high nutritional value of crayfish have made them popular among consumers, leading to the significant development of red swamp crayfish farming in the last two decades. Currently, it represents the largest proportion of commercially farmed freshwater crustaceans in China and has become an integral component of China’s aquatic economy. Crayfish are highly valued for their edibility and for their by-products, which have various important uses. This review discusses nutrient composition, active ingredients, safety evaluation, processing and preservation, and comprehensive utilization of crayfish by-products to explore and organize the existing knowledge about crayfish and to promote the growth of the crayfish industry. This comprehensive review aims to provide a basis for the optimal utilization and sustainable development of crayfish resources worldwide.

Strategies to control spoilage bacteria and biofilm formation are essential for minimizing food losses. Although Oleum ocimi gratissimi (OG) effectively preserves chill-stored fish, its specific inhibitory mechanisms against fish-derived spoilage bacteria remain unclear. This study investigated the antibacterial activity of OG against Aeromonas sobria, Pseudomonas versuta, and Shewanella putrefaciens. OG exhibited minimum inhibitory concentrations (MIC) of 2, 0.75, and 0.375 mg/mL and minimum bactericidal concentrations (MBC) of 3, 4, and 3 mg/mL against these bacteria, respectively. At MIC levels, OG inhibited planktonic growth by disrupting cell membranes, inducing adenosine triphosphate (ATP) leakage, reducing ATPase activity, and altering cellular morphology. Biofilm formation was completely suppressed, with OG further diminishing metabolic activity and extracellular polysaccharide/protein. These findings elucidate the dual role of OG in inhibiting bacterial growth and biofilm formation, highlighting its potential to enhance fish safety and shelf life by targeting biochemical and physiological pathways in spoilage bacteria.