Surrogate broodstock technology based on germ cell transplantation provides a powerful approach for conservation of aquatic genetic resources and enhancement of aquaculture production at scale. In fish, germline stem cells or primordial germ cells from donor gonads or embryos can be cryopreserved, transplanted into sterilized or germ cell-depleted recipients and then reconstituted as functional gametes of donor origin under controlled conditions. The strategy avoids technical limitations of oocyte cryopreservation, maternal inheritance of mitochondria, and long generation intervals for large-bodied or late-maturing species. Successful intra- and interspecific applications have been reported in commercially valuable taxa like pufferfish and sturgeons and also in Indian major carps where cryopreserved spermatogonia are revived in allogeneic hosts. The integration of surrogate broodstock systems with genome editing and environmentally benign sterilisation tools such as thermal manipulation further creates opportunities for secure cryopreservation, rapid propagation of elite germplasm and safe restoration of endangered populations over coming decades.