The characteristics of chitosan produced from upper and lower squilla species and compared to the analytical (commercial) chitosan were investigated. Two squilla species, Squilla mantis and Oratosquilla massavensis, were collected from Elanfoshy, Alexandria, Egypt, in Nov. 2022. Chitin and chitosan were extracted from the upper and lower shells of the species studied. The results showed that analytical (commercial) chitosan has low values of moisture,  degree of deacetylation (DD), solubility,  water binding capacity (WBC), and fat binding capacity (FBC), while the intrinsic viscosity and MW were higher in values than upper and lower squilla species chitosan samples. Four squilla chitosan samples exhibited regular absorption with little differences. Thermogravimetric analysis(TGA) curves showed that chitosan samples recorded a high thermal stability (200°C). Lower shells chitosan of S. mantis recorded the best radical scavenging activity followed by lower and upper shells chitosan samples of O. massavensis, and upper shells chitosan of S. mantis. Furthermore, the minimum inhibition concentration (MIC) for investigated chitosan samples has no general trend.  In conclusion, this study recommended that squilla chitosan is a promising shellfish and is considered a good substitute for shrimp chitosan, with additional applicability in high-temperature food processing.