Safeguarding economically important agricultural species has been driven by storing, evaluating, and distributing genetic resources as cryopreserved germplasm maintained in repositories. The value of germplasm repositories is being realized by the broader scientific community, especially for aquatic biomedical model systems. Cryopreservation pathways that are generalizable to a variety of organisms across biological levels of organization can provide a foundation for developing repositories and a means for addressing cross-taxa challenges. In collaboration with the National Resource for Aplysia (NRA, University of Miami), we are developing a generalizable cryopreservation pathway, including quality management and economics, that can be applied to the California sea hare, Aplysia californica. This is a biomedical model gastropod used to examine behavior, aging, and neural development. Cryopreservation and repository development for this species comes with many challenges, including those related to tissue types and developmental stages (Figure 1). For example, the sea hare produces egg strands with semi-rigid walls that hold capsules, each containing multiple embryos. Cryopreserving these strands presents challenges and is more like cryopreserving tissues rather than germplasm cells such as sperm. We exposed stage-4 embryos and veliger-stage larvae in the egg strand, to several common cryoprotectants at different concentrations and for different equilibration times to evaluate toxicity based on continued development. Cryoprotectants that allowed Aplysia to develop to veliger stage and hatch were used in cooling rate range-finding experiments. Frozen strands were thawed, and embryos or larvae were evaluated based on cell integrity and continued development. Assaying cryoprotectant toxicity and conducting cooling rate experiments are useful when developing cryopreservation protocols and are essential preliminary steps for building a cryopreservation pathway. By developing pathways with model organisms, we can leverage existing resources and information to bring much-needed generalization, scalability, and application to other aquatic species