Milkfish Chanos chanos

Milkfish is the mainstay of brackishwater pond farming across the Indo-Pacific, with 1,212,843 tonnes produced in 2024. FishBase records it at 180 cm standard length, 14 kg and fifteen years, living from fresh water through the sea. Its commercial value rests on extreme euryhalinity: FAO workshop proceedings put the tolerance of 21-day-old fry at 0 to 70 parts per thousand and record adults in lagoons at 158 ppt, which is why fish can be moved between the nursery, transition and rearing compartments of a pond system almost at will. It is a herbivorous generalist - juveniles and adults graze lablab, the benthic mat of blue-green algae, diatoms and associated invertebrates, plus filamentous green algae and detritus - so pond fertility, not pelleted feed, often drives growth, with rearing ponds stocked at 500 to 5,000 fingerlings per hectare and fish sold at 250 to 300 g. The clinical constraints follow from that. Feeding and growth are suppressed at 23 degrees Celsius, and the lethal limits for juveniles are 8.5 and 42.7 degrees. Oxygen depletion rather than ammonia causes mass mortality, with asphyxia in larger fish near 1.4 ppm. Broodstock mature slowly, at five years in sea cages and six to nine in tanks or ponds, so the industry long depended on wild-caught fry.