Milkfish

The milkfish can grow to 1.80 m (5 ft 11 in), but are most often no more than 1 m (39 in) in length. They can reach a weight of about 19 kg (42 lb) in pond. and an age of 15 years. They have an elongated and almost compressed body, with a generally symmetrical and streamlined appearance, one dorsal fin, falcate pectoral fins and a sizable forked caudal fin. The head is small relative to the body. The mouth is small and toothless. The body is olive green, with silvery flanks and dark bordered fins. They have 13–17 dorsal soft rays, 8–10 anal soft rays and 31 caudal fin rays. There are numerous fine intramuscular bones, which may complicate human consumption of the fish (see "Consumption" below).

Chanos chanos occurs in the Indian Ocean and across the Pacific Ocean, from South Africa to Hawaii and the Marquesas, from California to the Galapagos, north to Japan, south to Australia. A single specimen was reported in 2012 in the eastern Mediterranean Sea. In 1877, the California Fish and Game Commission introduced 100 milkfish from Hawaii to the inland waters of Solano County, California. The introduced population could not establish itself permanently and it is currently unknown how their presence affected the native ecosystem.

Milkfishes commonly live in tropical offshore marine waters around islands and along continental shelves, at depths of 1 to 30 m (3 ft 3 in to 98 ft 5 in). They also frequently enter estuaries and rivers.

Milkfish are omnivorous opportunistic feeders. Juvenile milkfish eat a variety of foods including phytoplankton, zooplankton, filamentous green algae, and small invertebrates. Similarly to juveniles, adults also eat benthic invertebrates and additionally planktonic and nektonic items such as clupeid juveniles.

Reproduction of milkfish in nature is far less understood than populations of milkfish bred and propagated in captivity (see "Aquaculture" below). In the wild, milkfish take 3–5 years to mature. Females can produce 0.5–6 million eggs and have the ability to spawn more than once a year. Spawning takes place at night, may be lunar periodic, and is strongly seasonal. Milkfish eggs are pelagic and range between 1.1 and 1.25 mm (0.043 and 0.049 in) in diameter. Spawning sites are clear, warm, shallow waters above sand or coral reefs. It is believed milkfish prefer these locations to minimize predation from benthic planktivores.

According to the International Union for Conservation of Nature, as of 2019, milkfish were not a threatened species. However, little information is available on wild stocks.