All bony fishes have lateral lines which can be used to sense pressure and to judge underwater currents and localized movements in the water. The barramundi lateral line extends onto the caudal fin. Barramundi have reflective eyes which allow them to see better in dark conditions. Barramundi also have a sense of smell. Modes of communication in barramundi are poorly understood.
Perception Channels: visual ; tactile ; acoustic ; vibrations ; chemical
This species is not listed as threatened or endangered by any international organization.
US Federal List: no special status
CITES: no special status
State of Michigan List: no special status
Barramundi are serially hermaphroditic, transforming from male to female at three to eight years of age (FAO, 1999; Guiguen, 1993). Moore (1979) suggests some individuals may not undergo this transition, based on a sex ratio of 3.8 males to 1 female.
Color and markings change from juveniles to adults (see "Physical Description").
Development - Life Cycle: metamorphosis
Although barramundi have not been shown to have any negative impacts, as large piscivores, they have the potential to kill off prey species if introduced into a non-native habitat. Nile Perch (Lates niloticus), are related to barramundi and are responsible for extinctions of native cichlids in Lake Victoria after having been introduced there (Morgan, 2004). According to Morgan et al. (2004), barramundi have limited potential to cause the same problems if introduced into Lake Kununurra in Western Australia.
Barramundi are valuable both as recreational and commercial fish, with a high, fairly stable price (Luna, 2008). They are stocked in lakes and ponds for recreational fishing and are also fished in freshwater creeks and estuaries (Morgan, 2004). Barramundi are heavily farmed in cages, as well as in freshwater and saltwater ponds (Webster, 2002). Worldwide capture peaked in 2000 at 74,207 metric tonnes and declined to 57,074 tonnes caught in 2005 (FAO, 2008; but see Webster, 2002). Aquaculture of barramundi has grown rapidly with 1646 tonnes (4,357,000 USD) produced in 1984, 18,564 tonnes (70,720,000 USD) produced in 1994, and 30,970 tonnes (79,034,000 USD) produced in 2005.
Since it is a white fish with delicate flavor, barramundi is also becoming popular in the United States. As of 2006, the indoor fish farming interest Australis, based in Massachusetts, was shipping 40,000 lbs of fish per week (Pierce, 2006).
Positive Impacts: food
Barramundi are predators and prey (Davis, 1985; Hitchcock, 2007; and Shine, 1986). They help support pelicans and file snakes, among other possible predators, as well as controlling the populations species on which they prey.
Barramundi are opportunistic predators. They eat microcrustaceans such as copepods and amphipods as juvenile fish under 40 mm. As larger juveniles they eat macrocrustaceans like Penaeidae and Palaemonidae. These crustacean prey are found mainly near the bottom of the water column, so this diet also protects juveniles from most of their predators, which hunt closer to the water surface. Mollusks are consumed to a lesser degree. When barramundi are around 80 mm, they begin to eat macrocrustaceans and pelagic bony fishes. Larger fish have diets of around 80% bony fish. Barramundi swallow their food whole, sucking their prey into their fairly large mouths. Moderate cannibalism is fairly common in barramundi (Davis, 1985).
Animal Foods: fish; insects; mollusks; aquatic crustaceans; other marine invertebrates; zooplankton
Primary Diet: carnivore (Piscivore , Eats non-insect arthropods, Molluscivore )
Lates calcarifer, known as barramundi, barramundi perch, giant sea perch, or Asian sea bass, is native to coastal areas in the Indian and Western Pacific Oceans. This includes coastal Australia, Southeast and Eastern Asia, and India (Luna, 2008). According to Luna, this distribution is Indo-West Pacific.
According to a 2008 study of barramundi from Burma and Australia, these fish may be two species (Ward, 2008). The study used DNA barcoding: the comparison of a particular locus (600 base pairs of the cytochrome c oxidase I gene) on the mitochondrial DNA (mtDNA). The study found that there was a significant enough difference in the mtDNA of the fish from the two locations that the species L. calcarifer may be split to take these differences into account. The study only examined fish from two locations, so Ward et al. (2008) recommended further study across the range.
Biogeographic Regions: indian ocean (Native ); pacific ocean (Native )
Barramundi are catadromous, spending most of their life in fresh water and migrating to salt water in order to breed. Smaller fish are found in rivers and streams and larger fish are found in the ocean and estuaries (Pender, 1996; FAO, 1999). There are exceptions to this patter, however, with populations of all sizes of fish found throughout their natural range. Pender and Griffin confirmed through chemical analysis that there are populations that spend their entire life cycle in salt water, in brackish water, or in fresh water (Pender, 1996). Barramundi can survive in a wide range of salinities, but must be introduced slowly to a new salinity to avoid shock (Webster, 2002). Barramundi generally prefer to hide under logs or other objects.
Barramundi are demersal, meaning they spend most of their time near but not on the bottom of a body of water. They are found at depths of ten to forty meters (Luna, 2008). In barramundi fish farming cages are generally placed two meters below the surface (Webster, 2002).
Range depth: 40 to 10 m.
Habitat Regions: tropical ; saltwater or marine ; freshwater
Aquatic Biomes: rivers and streams; coastal ; brackish water
Other Habitat Features: estuarine
Little is known about longevity of barramundi.
Barramundi are large fish, with a maximum length of over two meters, although they are more commonly around 1.5 meters. Barramundi can have a mass over 55 kilograms. According to the FAO species identification guide, they have a moderately deep, elongate, and compressed body. Barramundi have pointed snouts and large mouths, with jaws extending past the eyes. Nostrils are close together. The dorsal fin is deeply incised, with separate spiny and soft dorsal fins. The spiny dorsal fin has seven to nine spines, and the soft dorsal fin has ten to eleven soft rays. The anal fin has three spines and seven to eight soft rays. Pelvic and pectoral fins are present. These fish have a distinct caudal peduncle, or tail muscle, with a rounded caudal fin. The lateral line extends onto the caudal fin.
The scales of barramundi are firmly fixed and ctenoid. Adult barramundi are silver with darker, olive or blue-gray backs. In turbid (cloudy) water, coloration is darker. Juveniles are brown (sometimes grayish-brown) with three white stripes on the head and scattered white spots elsewhere. The markings can be dimmed or may disappear at will. The fins do not have markings. The eyes are golden-brown with a red reflective glow.
Average mass: 55 kg.
Range length: >2 (high) m.
Average length: 1.5 m.
Other Physical Features: ectothermic ; heterothermic ; bilateral symmetry
Sexual Dimorphism: female larger
Although barramundi are opportunistic predators (Davis, 1985), they are also a prey species. The patterns present on the scales of juvenile barramundi (FAO, 1999), in combination with the fact that juveniles reside in protected mangroves and swamps (Moore, 1982; Russell, 1985; and FAO, 1999) suggests a need to protect against predators. There are several species that have been found to prey on juvenile barramundi. In an analysis of stomach contents Davis (1985) demonstrated that barramundi over 40 mm consume juvenile barramundi as part of their diet. Australian pelicans (Pelecanus conspicillatus) (Hitchcock, 2007) and file snakes (Acrochordus arafurae) (Shine, 1986) feed on both juvenile and adult barramundi.
Known Predators:
Anti-predator Adaptations: cryptic
Barramundi spawn seasonally (Moore, 1982). Since they are broadcast spawners (Luna, 2008; Moore, 1982), it can be inferred that there is very little social interaction among individuals. Males and females congregate for the purpose of spawning. Spawning events tend to take place at the mouths of estuaries on or near a full moon, after which tides draw the eggs up into the estuaries (Luna, 2008).
Mating System: polygynandrous (promiscuous)
Lates calcarifer is catadromous; migrating to the mouths of rivers and estuaries in order to breed (FAO, 1999; Moore, 1982; Webster, 2002; Pender, 1996; Russel; 1985). According to Moore, the eggs of fish not exposed to high salinity water do not develop fully, however, Pender and Griffen (1996) concluded that there are populations that spend their entire life cycles in freshwater, estuarine, or saltwater environments, so there may be exceptions to the requirement for high salinities.
There is one spawning season per year towards the end of the dry season and the beginning of the rainy season in the period from October to February (Moore, 1982). Females carry from 2.3 to 32.2 million eggs and can either shed them all at once or as little as 10% at a time (Moore, 1982). Because Lates calcarifer is a broadcast breeder, it can be inferred that there is little interaction between males and females. However, barramundi tend to spawn around the full moon, when tides will carry the eggs back into estuaries (Luna, 2008).
Lates calcarifer is serially hermaphroditic with males reaching maturity at 37 to 72 cm and changing into females starting at 73 cm, at around five years, three to five years, or six to eight years depending on the source (Moore, 1979, FAO, 1999; Guiguen, 1993). According to Guiguen (1993) males mature at three to five years, but this study was conducted in cage farmed fish, which may have different maturation times than wild fish. Some male specimens do get larger than 73 cm. The transition from male to female is short, lasting as little as a week, and may not occur in all individuals according to Moore (1979).
Chemical levels in the scales of fish from southern Papua New Guinea have indicated that adult barramundi do not always migrate to breeding grounds to spawn, with a lifetime non-participation rate of as much as 50% (Milton, 2005).
Breeding interval: Breeding occurs once yearly in barramundi
Breeding season: Breeding generally occurs from October to February.
Range number of offspring: 2,300,000 to 32,200,000.
Range age at sexual or reproductive maturity (female): 2 to 8 years.
Range age at sexual or reproductive maturity (male): 3 to 5 years.
Key Reproductive Features: iteroparous ; seasonal breeding ; sequential hermaphrodite (Protandrous ); sexual ; fertilization (External ); broadcast (group) spawning; oviparous
Lates calcarifer is a nonguarding species; there is no parental involvement in the development of fry and juvenile fish (Luna, 2008).
Parental Investment: no parental involvement; pre-fertilization (Provisioning, Protecting: Female)
