The shipping dewar positional cooling device (SDPCD, known as the ‘Cajun Ejector’, v3.10.45) is a 3-D printable device that can assist cryopreservation with various standard cooling rates by use with existing standard shipping dewars. Efforts in development of germplasm repositories to preserve genetic resources of aquatic species are impeded globally by a lack of standardized, inexpensive, reproducible, and portable cryopreservation technologies. The present work demonstrates a 3-D printed standardizable freezing device that can be used with nitrogen vapor shipping dewars for on-site sperm cryopreservation for aquatic species and be distributed as open-hardware. This device could hold 22 French straws (0.25-mL or 0.5-mL) and a quick-release ring design could eject straws directly into a canister inside a dewar by pressing a button after freezing. The final prototypes produced cooling rates of 1 to 68°C/min for 0.25-mL straws, and 3 to 37°C/min for 0.5-mL straws. More information on https://3d.nih.gov/entries/3DPX-017520