The California Sea Hare (Aplysia californica) is a biomedical model used for studies in molecular neurobiology, electrophysiology, learning, and memory. As with other models, research communit ies often require maintenance of different genetic lines. C ryopreservation has been proposed as one method to preserve these lines. In many aquaculture species , sperm is cryopreserved, but because A. californica is an internal fertilizer , their sperm is difficult to extract. Thus, we are investigating if embryos and larvae can be cryopreserved instead. During spawning, m ultiple embryos are enclosed within egg capsules which are packaged within a strand (Figure 1A) . The multiple barriers associated with the strand make it difficult to determine how well and how quickly cryoprotectants can penetrate embryos, information that is vital for developing a cryopreservation protocol. An alternative could be to freeze embryos or larvae free from the strand. Egg strands were cut into 1-cm pieces; six were added to 32 ppt artificial sea water (ASW) , and six were cut open to release embryos into the ASW. Samples were observed for 16 days at 16°C or until >90% of the individuals died. Development was assessed and larval stage demographics were counted for each sample. Approximately 87% of embryos in strands developed normally into the early veliger stage , while only 8% of the free larvae developed into early veligers and of these, more than half exhibited abnormal development . The remaining free embryos arrested at an earlier developmental stage, trochophore larvae (Figure 1C). This suggests that the embryos depend on the environment provided within the strand to undergo normal development . Alt hough some A. californica embryos can develop outside the strand and capsule, they developed slower and abnormally. Further research to develop ways to culture embryos outside the strand and capsule is needed to determine whether cryopreserving free larvae would be feasible.