Fingerling

A fingerling is a juvenile fish that has grown beyond the fry stage to roughly the size of a human finger, conventionally 2–10 cm or about 1–10 g depending on species, and that is fully weaned onto formulated feed and ready for transfer from the hatchery or nursery into grow-out. Fingerling production is where hatchery skill converts into farm value: nursery rearing involves gradual grading to keep size variation narrow (a spread beyond 20–30% in mean weight invites hierarchies where larger fish outcompete smaller ones), controlled weaning from live feed to pellets, and vaccination or health certification before transfer. Survival from fry to fingerling of 80–95% is achievable with good water quality, live-feed transition, and pathogen exclusion. The quality of the fingerling lot — uniformity, absence of deformities, confirmed disease-free status — sets the growth curve and FCR for the entire subsequent grow-out cycle, which is why experienced farmers audit hatcheries rather than buying on price alone. In pond farming, stocking of fingerlings at 1–5 per m2 follows acclimation to pond temperature and salinity to avoid transfer shock. Fingerling links hatchery, fry, nursery-phase, grading-size-sorting, and weaning-feed-transition into the early life-stage chain.