Bandang

Milkfish are most vulnerable to predators in the egg, larval, and fry stages. In order to minimize the impact of predation, milkfish produce large amounts of eggs in deep water (Bagarinao 1994).

Known Predators:

• Indo-Pacific tarpon Megalops cyprinoides
• tenpounder Elops machnata

Not much is known about how milkfish communicate with one another during mating or how they perceive the environment. Like all fishes, they have a well-developed sensory system, including a lateral line system and a well-developed sense of vision. Milkfish are members of the Ostariophysi, which produce and respond to an alarm substance. This alarm substance is produced when the skin of the milkfish has been injured, particularly by a predator. This alarm substance warns other fish to seek a hiding place in order to avoid the predator.

Communication Channels: chemical

Other Communication Modes: pheromones

Perception Channels: visual ; tactile ; chemical

Chanos chanos populations seem to be stable, this species is not listed on any conservation registry.

US Federal List: no special status

CITES: no special status

Fertilized milkfish eggs can be found in the open sea of tropical waters. The eggs are spherical in shape and range from 1.1 to 1.25 mm in diameter (Bagarinao 1994). The eggs have a yellowish yolk and lack oil globules. The outer embryonic membrane seems to be granular with a distinct, segmented pattern. There is a narrow perivitelline space present in milkfish eggs (Garcia 1990). Development of the embryo takes about 20 to 35 hours in water temperatures of 26 to 32°C and of salinity 29 to 34 ppt (Bagarinao 1994).

Once the eggs hatch, the larvae are about 3.5 mm total length. At hatching, the larvae’s eyes are not pigmented and their mouth is not open (Bagarinao 1994). For about five days milkfish larvae depend solely on their yolk for nutrients (Garcia 1990).

Milkfish larvae go through a series of complex morphological, physiological, and behavioral stages, which last about 2 to 4 weeks, before becoming juveniles. Younger larvae occur in water depths of 20 to 30 m, while older larvae occur near the water’s surface. Younger larvae occur both near and far from shore. More advanced larval stages begin to migrate towards nearshore areas, and are found most frequently there (Bagarinao 1994; Garcia 1990). Milkfish larvae migrate towards shore when they are about 10 to 17 mm total length (Garcia 1990).

Once milkfish become larger than 20 mm total length they are considered juveniles. Juveniles appear to have the same characteristics and structure of adult milkfish (Garcia 1990). Juveniles enter brackish water and coastal wetland habitats where the food supply is more abundant. The kind of habitat, depth, and connection with the sea has been found to be the factors determining maximum size and duration of stay of juvenile milkfish in the nursery grounds (Bagarinao 1994).

Growth and development of milkfish is influenced by water temperature. Temperatures between 23.7 to 33°C seem to be the optimal temperatures for development of milkfish larvae. The rate of development is faster at higher temperatures. Temperatures lower than 20°C and up to 22.6°C cause young milkfish to be rather sluggish, thus making them more vulnerable to predation.

Development - Life Cycle: metamorphosis

There are no known adverse effects of Chanos chanos on humans.

Milkfish are commercially raised for food in the Philippines and Indonesia (Gale 2003). More than a quarter of a million tons of milkfish are harvested every year in brackish ponds in Indonesia, Taiwan, and the Philippines. These fish contribute around 60% of the total fish production from aquaculture in Southeast Asia (Garcia 1990).

Positive Impacts: food

Not much is known about the effects that milkfish have on the ecosystem. They are important as both predators and prey of other fish species and of coastal planktonic communities.

Milkfish feed on a variety of foods depending on the type of environment. As larvae they feed on zooplankton. As they develop into juveniles they start to feed on benthic items. The most common food items for juveniles are cynobacteria, diatoms, detritus, green algae, and invertebrates such as small crustaceans and worms. Adults feed on similar items, and on planktonic and nektonic prey such as clupeid juveniles. Adult milkfish have a well-developed epibranchial organ, which is an extension of the alimentary canal. The epibranchial organ allows milkfish to digest plant material (Gale 2003).

Animal Foods: fish; aquatic or marine worms; aquatic crustaceans; other marine invertebrates; zooplankton

Plant Foods: algae

Other Foods: detritus

Primary Diet: omnivore

Milkfish are native to regions in the Indian and Pacific Oceans. Their range spans from the east coast of Africa and Madagascar to the coasts of India and Southeast Asia around Malaysia, Indonesia, New Guinea, Australia, northward to the southern tip of Japan, and eastward into the Pacific Islands.

Biogeographic Regions: indian ocean (Native ); pacific ocean (Native )

Milkfish are usually found along the coasts of continents or islands, particularly where reefs are well developed. They also occur in large coastal lagoons. Milkfish are found in tropical waters, rarely in waters that are affected by cold ocean currents. They are found in clear, shallow, saline, and warm waters above 20°C. Adult milkfish also occur in freshwater lakes in the Philippines, Indonesia, and Madagascar. Juveniles are found in large coastal lagoons, atolls, and freshwater lakes. The depth range of the milkfish is 0 to 30 m.

Range depth: 0 to 30 m.

Habitat Regions: tropical ; saltwater or marine ; freshwater

Aquatic Biomes: reef ; lakes and ponds; coastal ; brackish water

Not much is known about natural mortality rates of adult milkfish, but the shortest recorded lifespan of milkfish is 3 years and the maximum lifespan is 15 years. Most mortality occurs at the egg and larval stages.

Range lifespan
Status: wild: 3 to 15 years.

Average lifespan
Status: captivity: 15 years.

Milkfish have a long, muscular, silvery body with a forked tail. The forked tail is fairly large and strong, thus making them fast and powerful swimmers of the open sea (Bagarinao 1994). Milkfish have large eyes, a pointed snout with a terminal mouth, and cycloid scales. The total length ranges from 50 cm to 180 cm (Bagarinao 1994, Gale 2003). They weigh between 4 and 14 kg (Bagarinao 1994). Milkfish have 13 to 17 rays in their dorsal fin, 6 to 8 anal rays, 15 to 17 pectoral rays, and 10 to 11 pelvic rays (Gale 2003).

There have been rare occurrences of variant forms of milkfish. One variant, found in the Philippines, has distinctly long dorsal, pelvic and anal fins, and the caudal fin is as long as the length of the body. This variant is the ‘goldfish-type’ milkfish. Another variant, seen in Hawaii, Indonesia, and Australia, is called the ‘shad-type’ milkfish because its length-to-depth ratio is 2.0 to 2.5 instead of the typical 3.5 to 4.0.

Range mass: 4 to 14 kg.

Range length: 50 to 180 cm.

Other Physical Features: ectothermic ; heterothermic ; bilateral symmetry

Sexual Dimorphism: sexes alike

Not much is known about mating systems and behaviors in milkfish.

Milkfish breed near shore in clean, clear, saline, warm, and shallow waters over sand or coral reefs. These spawning locations are as close as 6 km off shore (Bagarinao 1994) but are no more than 30 km off shore (Garcia 1994). Milkfish may spawn more than once a year and spawning usually takes place during the night. Spawning is highly seasonal and may be influenced by the lunar cycle (Bagarinao 1994). Milkfish breeding season is longer near the equator than at higher latitudes. The length of the spawning season may be influenced by surface water temperatures in certain areas (Garcia 1990).

Breeding interval: Milkfish may spawn more than once a year.

Breeding season: Spawning usually takes place at night and may be influenced by the lunar cycle. Milkfish breeding may occur throughout much of the year, depending on latitude.

Range number of offspring: 0.5 million eggs to 6 million eggs.

Range gestation period: 20 to 35 hours.

Range age at sexual or reproductive maturity (female): 3 to 10 years.

Range age at sexual or reproductive maturity (male): 3 to 10 years.

Key Reproductive Features: iteroparous ; seasonal breeding ; gonochoric/gonochoristic/dioecious (sexes separate); sexual ; fertilization (External ); broadcast (group) spawning; oviparous

There does not appear to be any parental involvement once the eggs have been released into the water.

Parental Investment: no parental involvement; pre-fertilization (Provisioning, Protecting: Female)

Acanthocephalus Infestation. Parasitic infestations (protozoa, worms, etc.)

Caligus Infestation 4. Parasitic infestations (protozoa, worms, etc.)

Cavisoma Infestation. Parasitic infestations (protozoa, worms, etc.)

Caligus Infestation 3. Parasitic infestations (protozoa, worms, etc.)

Haplorchis Infestation 1. Parasitic infestations (protozoa, worms, etc.)

Posthodiplostomum Infestation. Parasitic infestations (protozoa, worms, etc.)

Procerovum Infestation 1. Parasitic infestations (protozoa, worms, etc.)

Heterophyopsis Infestation. Parasitic infestations (protozoa, worms, etc.)

Ambiphyra Infestation. Parasitic infestations (protozoa, worms, etc.)

Alitropus Infestation. Parasitic infestations (protozoa, worms, etc.)

Trichodinosis. Parasitic infestations (protozoa, worms, etc.)

Fin-rot Disease (late stage). Bacterial diseases

Caligus Infestation 12. Parasitic infestations (protozoa, worms, etc.)

Transversotrema Infestation 3. Parasitic infestations (protozoa, worms, etc.)

Ichthyoxenus Disease. Parasitic infestations (protozoa, worms, etc.)

Vibriosis Disease (general). Bacterial diseases

Spawns in clear shallow waters above a bottom of sand or coral and at a distance of not more than 30 km from the shore. Females spawn up to 5 million eggs which hatch in about 24 hr. The larvae seek out clear coastal and estuarine waters warmer than 23°C with 10-32 salinity and abundant phytoplankton. Spawning and fertilization take place at night.

Amphidromous. Refers to fishes that regularly migrate between freshwater and the sea (in both directions), but not for the purpose of breeding, as in anadromous and catadromous species. Sub-division of diadromous. Migrations should be cyclical and predictable and cover more than 100 km.Characteristic elements in amphidromy are: reproduction in fresh water, passage to sea by newly hatched larvae, a period of feeding and growing at sea usually a few months long, return to fresh water of well-grown juveniles, a further period of feeding and growing in fresh water, followed by reproduction there (Ref. 82692).

Genolinea Infestation. Parasitic infestations (protozoa, worms, etc.)

Feeds on algae as well as on zooplankton and benthic invertebrates (Ref. 11889).Temperature is the prime factor responsible for limiting the habitat of the species to tropical and subtropical regions of the Indian and the Pacific Ocean. Also, susceptibility to predation limits the distribution of the species.

Dorsal spines (total): 2; Dorsal soft rays (total): 13 - 17; Analspines: 2; Analsoft rays: 8 - 10; Vertebrae: 46

This species is characterized by the following: body elongate and somewhat compressed; mouth small and toothless; single dorsal about mid-level of the body; pectoral fins falcate; caudal fin large and deeply forked; no scutes on belly; branchiostegal rays 4. Colour of the body olive green dorsally; flanks silvery; unpaired fins with dark margins (Ref. 49, 117228).

Anchor worm Disease. Parasitic infestations (protozoa, worms, etc.)

Fin Rot (early stage). Bacterial diseases

Nematode Infestation. Parasitic infestations (protozoa, worms, etc.)

Scolex Infestation (Scolex pleuronectis). Parasitic infestations (protozoa, worms, etc.)

Cryptobia Infestation. Parasitic infestations (protozoa, worms, etc.)

False Fungal Infection (Apiosoma sp.). Parasitic infestations (protozoa, worms, etc.)

Transversotrema Infestation. Parasitic infestations (protozoa, worms, etc.)

Riboscyphidia Infestation. Parasitic infestations (protozoa, worms, etc.)

Tripartiella Disease. Parasitic infestations (protozoa, worms, etc.)

Ceratomyxa Infestation. Parasitic infestations (protozoa, worms, etc.)

Leptotheca Infestation. Parasitic infestations (protozoa, worms, etc.)

Isorchis Infestation. Parasitic infestations (protozoa, worms, etc.)

Adults are found in offshore marine waters and shallow coastal embayments, but also frequently enter estuaries and occasionally penetrate freshwater streams (Ref. 44894, 52331). They occur in small to large schools near the coasts or around islands where reefs are well developed. Eggs and larvae are pelagic up to 2-3 weeks. Older larvae migrate onshore and settle in coastal wetlands (mangroves, estuaries) during the juvenile stage, or occasionally enter freshwater lakes. Juveniles and sub-adults return to sea where they mature sexually. Mature adults spawn only in fully saline water. Larvae eat zooplankton; juveniles and adults eat cyanobacteria, soft algae, small benthic invertebrates, and even pelagic fish eggs and larvae. Larvae are collected from rivers and are grown in culture ponds into juveniles which are marketed fresh, smoked, canned or frozen. Brood stocks can be raised and spawned in captivity to produce larvae in the hatchery (Ref. 12868). This species can thrive and grow in water as hot as 32° C (Ref. 9987).

fisheries: highly commercial; aquaculture: commercial; gamefish: yes; bait: usually; price category: unknown; price reliability:

廣泛分布在印度-太平洋的熱帶及亞熱帶海域，但東太平洋地區較為少見。臺灣南部較常見。

是臺灣的主要養殖魚種之一，魚肉細緻鮮美，為家庭食用魚的佳餚，舉凡煎、烤、煮、蒸、炸、醃、燒等，味道皆不錯。除了家庭直接食用外，加工製品之虱目魚丸也深受消費者喜愛，此外近年來開發的虱目魚罐頭、虱目魚乾、虱目魚漿、燒烤虱目魚等也逐漸打開市場。由於此魚對環境適應能力強，不但成長快速，抗病力強，單位生產量高，是將來解決糧食問題的最佳魚種之一。而有關於此魚諸多魚名的由來，流傳甚多，較為人們所傳的有以下幾個：1.根據臺灣通史記載：「臺南沿海事以蓄魚為業，其魚為麻薩末，番語也」；2.有學者認為西班牙語系稱虱目魚為Sab

體延長，稍側扁，截面呈卵圓形。頭鈍，中等大。吻圓鈍。眼大，脂性眼瞼非常發達。口端位，口小；上頜中間部位具一凹刻，下頜中央則具突起；無牙齒。身體被覆細小型的圓鱗，不易脫落；側線發達，幾近平直；在背鰭與臀鰭的基部形成鱗鞘；胸、腹鰭則有寬大的腋鱗；尾鰭基部另有2片大鱗。背鰭位於體中部前方，具軟條14；臀鰭位於體之後半部，具軟條11；腹鰭軟條12；尾鰭深叉型。體背部呈青綠色，體側下方和腹部則為銀白色。

屬於熱帶及亞熱帶水域的魚類，能適應各種不同鹽度的棲息環境，從河川中的淡水到河口紅樹林區、潟湖以及海洋中的砂質底地形或珊瑚礁區的環境等，皆有其蹤跡。屬雜食性魚類，養殖時喜歡攝食魚池底之藍綠藻及矽藻等。母魚一次可產上百萬顆的卵，春、秋季之仔稚魚期常在靠海的近岸河口區隨波逐流，漁民撈捕後，售於養殖戶蓄養。人工繁殖目前亦已成功。但虱目魚較不能耐寒，14℃ 以下抵抗力減低，10℃以下有被凍死之現象，故養殖時需有越冬之準備。

The milkfish (Chanos chanos) is the sole living species in the family Chanidae, but at least five extinct genera from the Cretaceous have been found. The repeating scientific name (tautonym) is from Greek khanos (χάνος ‘mouth’).

The species has many common names. The Hawaiian name for the fish is awa, and in Tahitian it is ava. It is called bangús in the Philippines, where it is popularly known as the national fish, although the National Commission for Culture and the Arts has stated that this is not the case, as it has no basis in Philippine law. In the Nauruan language, it is referred to as ibiya. Milkfish is also called bandeng or bolu in Indonesia.

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.

Milkfish commonly live in tropical offshore marine waters around islands and along continental shelves, at depths of 1 to 30 m. They also frequently enter estuaries and rivers.

Adults occur in small to large schools near the coasts or around islands where reefs are well developed. Eggs and larvae are pelagic up to 2-3 weeks. Older larvae migrate onshore and settle in coastal wetlands (mangroves, estuaries) during the juvenile stage, or occasionally enter freshwater lakes. Juveniles and subadults return to sea where they mature sexually. Spawns only in fully saline water. Larvae eat zooplankton; juveniles and adults eat cyanobacteria, soft algae, small benthic invertebrates, and even pelagic fish eggs and larvae. Larvae are collected from rivers and are grown in culture ponds into juveniles, which are marketed fresh, smoked, canned and frozen. Broodstocks can be raised and spawned in captivity to produce larvae in the hatchery (Ref. 9815). Can thrive and grow in water as hot as 32° C (Ref. 9987).