Archerfish
Encyclopedia
The archerfish are a family
(Toxotidae) of fish
known for their habit of preying on land based insect
s and other small animals by literally shooting them down with water droplets from their specialized mouths. The family is small, consisting of seven species in the genus Toxotes; which typically inhabit brackish
waters of estuaries and mangroves, but can also be found in the open ocean as well as far upstream in fresh waterIndia
to the Philippines
, Australia
, and Polynesia
.
Archerfish or Spinnerfish bodies are deep and laterally compressed, with the dorsal fin
set far back, and the profile a straight line from dorsal fin to mouth. The mouth is protractile, and the lower jaw juts out. Sizes are generally small,about 5–10 cm but T. chatareus can reach 40 centimetres (15.7 in).
Archerfish are popular for aquaria
.
; adult fish almost always hit the target on the first shot. They can bring down an insect that includes grasshoppers, spiders and butterflies on a branch overhanging the water, 3 m above the water's surface. This is partially due to their good eyesight, but also their ability to compensate for the refraction
of light as it passes through the air water interface when aiming for their prey. They typically spit at prey at a mean angle of about 74 degrees from the horizontal, but can still aim accurately when spitting at angles between 45 and 110 degrees.
When an archerfish selects its prey, it rotates its eye so that the image of the prey falls on a particular portion of the eye in the ventral temporal periphery of the retina and its lips just break the surface, squirting a jet of water at its victim. It does this using the narrow groove in the roof of its mouth. It presses its tongue against this groove to form a narrow channel, then contracts its gill covers to force a powerful jet of water through the channel. The resulting jet of water can be up to 2–5 m long, but their accuracy only allows them to shoot insects 1–2 m away depending on body size. The fish can alter the power of the shot for prey of different sizes. If the first shot does not knock the victim into the water, the archerfish will keep trying.
Young archerfish start shooting when they are about 2.5 cm long, but are inaccurate at first and must learn from experience. During this learning period, they hunt in small schools
. This way, the probability is enhanced that at least one jet will hit its target.
Archerfish will often leap out of the water and grab an insect in their mouth if it happens to be within reach.
Individuals typically prefer to remain close to the surface of the water.
Family (biology)
In biological classification, family is* a taxonomic rank. Other well-known ranks are life, domain, kingdom, phylum, class, order, genus, and species, with family fitting between order and genus. As for the other well-known ranks, there is the option of an immediately lower rank, indicated by the...
(Toxotidae) of fish
Fish
Fish are a paraphyletic group of organisms that consist of all gill-bearing aquatic vertebrate animals that lack limbs with digits. Included in this definition are the living hagfish, lampreys, and cartilaginous and bony fish, as well as various extinct related groups...
known for their habit of preying on land based insect
Insect
Insects are a class of living creatures within the arthropods that have a chitinous exoskeleton, a three-part body , three pairs of jointed legs, compound eyes, and two antennae...
s and other small animals by literally shooting them down with water droplets from their specialized mouths. The family is small, consisting of seven species in the genus Toxotes; which typically inhabit brackish
Brackish water
Brackish water is water that has more salinity than fresh water, but not as much as seawater. It may result from mixing of seawater with fresh water, as in estuaries, or it may occur in brackish fossil aquifers. The word comes from the Middle Dutch root "brak," meaning "salty"...
waters of estuaries and mangroves, but can also be found in the open ocean as well as far upstream in fresh waterIndia
India
India , officially the Republic of India , is a country in South Asia. It is the seventh-largest country by geographical area, the second-most populous country with over 1.2 billion people, and the most populous democracy in the world...
to the Philippines
Philippines
The Philippines , officially known as the Republic of the Philippines , is a country in Southeast Asia in the western Pacific Ocean. To its north across the Luzon Strait lies Taiwan. West across the South China Sea sits Vietnam...
, Australia
Australia
Australia , officially the Commonwealth of Australia, is a country in the Southern Hemisphere comprising the mainland of the Australian continent, the island of Tasmania, and numerous smaller islands in the Indian and Pacific Oceans. It is the world's sixth-largest country by total area...
, and Polynesia
Polynesia
Polynesia is a subregion of Oceania, made up of over 1,000 islands scattered over the central and southern Pacific Ocean. The indigenous people who inhabit the islands of Polynesia are termed Polynesians and they share many similar traits including language, culture and beliefs...
.
Archerfish or Spinnerfish bodies are deep and laterally compressed, with the dorsal fin
Dorsal fin
A dorsal fin is a fin located on the backs of various unrelated marine and freshwater vertebrates, including most fishes, marine mammals , and the ichthyosaurs...
set far back, and the profile a straight line from dorsal fin to mouth. The mouth is protractile, and the lower jaw juts out. Sizes are generally small,about 5–10 cm but T. chatareus can reach 40 centimetres (15.7 in).
Archerfish are popular for aquaria
Aquaria
Aquaria may refer to:*Aquarium, in the plural*Aquaria , a computer game*Aquaria , a Brazilian metal band*Aquaria, one of the Twelve Colonies in Battlestar Galactica...
.
Capture of prey
Archerfish are remarkably accurate in their shootingProjectile use by living systems
Although projectiles are commonly used in human conflict, projectile use by living systems other than humans is relatively rare.-Liquid projectiles:...
; adult fish almost always hit the target on the first shot. They can bring down an insect that includes grasshoppers, spiders and butterflies on a branch overhanging the water, 3 m above the water's surface. This is partially due to their good eyesight, but also their ability to compensate for the refraction
Refraction
Refraction is the change in direction of a wave due to a change in its speed. It is essentially a surface phenomenon . The phenomenon is mainly in governance to the law of conservation of energy. The proper explanation would be that due to change of medium, the phase velocity of the wave is changed...
of light as it passes through the air water interface when aiming for their prey. They typically spit at prey at a mean angle of about 74 degrees from the horizontal, but can still aim accurately when spitting at angles between 45 and 110 degrees.
When an archerfish selects its prey, it rotates its eye so that the image of the prey falls on a particular portion of the eye in the ventral temporal periphery of the retina and its lips just break the surface, squirting a jet of water at its victim. It does this using the narrow groove in the roof of its mouth. It presses its tongue against this groove to form a narrow channel, then contracts its gill covers to force a powerful jet of water through the channel. The resulting jet of water can be up to 2–5 m long, but their accuracy only allows them to shoot insects 1–2 m away depending on body size. The fish can alter the power of the shot for prey of different sizes. If the first shot does not knock the victim into the water, the archerfish will keep trying.
Young archerfish start shooting when they are about 2.5 cm long, but are inaccurate at first and must learn from experience. During this learning period, they hunt in small schools
Shoaling and schooling
In biology, any group of fish that stay together for social reasons are said to be shoaling , and if, in addition, the group is swimming in the same direction in a coordinated manner, they are said to be schooling . In common usage, the terms are sometimes used rather loosely...
. This way, the probability is enhanced that at least one jet will hit its target.
Archerfish will often leap out of the water and grab an insect in their mouth if it happens to be within reach.
Individuals typically prefer to remain close to the surface of the water.
Species
- Toxotes blythiiToxotes blythiiToxotes blythii is a perciform fish of genus Toxotes. It is amphidromous and found in Myanmar. T. blythii is not of interest in fisheries. This species was formerly thought to be identical to T. microlepis . However, differences in structure and colouration caused the splitting of T. blythii into...
BoulengerGeorge Albert BoulengerGeorge Albert Boulenger FRS was a Belgian-British zoologist who identified over 2000 new animal species, chiefly fish, reptiles and amphibians.-Life:...
, 1892. - Largescale archerfish, Toxotes chatareusToxotes chatareusToxotes chatareus, sometimes known by the common names seven-spot archerfish or largescale archerfish, is a species of perciform fish in the archerfish genus Toxotes. They are usually no larger than but may grow up to . Unlike most archerfish, T. chatareus are sooty rather than silvery in...
(Hamilton, 1822). - Banded archerfishBanded archerfishThe banded archerfish is a brackish water perciform fish of the archerfish genus Toxotes. It is silvery in colour and has a dorsal fin towards the posterior end. It has distinctive, semi-triangular markings along its sides. It is best known for its ability to spit a jet of water to "shoot down"...
, Toxotes jaculatrix (PallasPeter Simon PallasPeter Simon Pallas was a German zoologist and botanist who worked in Russia.- Life and work :Pallas was born in Berlin, the son of Professor of Surgery Simon Pallas. He studied with private tutors and took an interest in natural history, later attending the University of Halle and the University...
, 1767). - Toxotes kimberleyensisToxotes kimberleyensisToxotes kimberleyensis is a species of Archerfish found in the Kimberley region of western Australia. It was first named by Allen in 2004, and is commonly known as the Kimberley archerfish, Largescale archerfish, or the Western archerfish.Members of this species used to be thought to belong to a...
Allen, 2004. - Primitive archerfish, Toxotes lorentziToxotes lorentziToxotes lorentzi is a tropical freshwater fish found in New Guinea, Australia, and Indonesia. It was first named by Weber in 1910, and is commonly known as the Primitive archerfish or the Lorent'z archerfish....
Weber, 1910. - Smallscale archerfishSmallscale archerfishThe smallscale archerfish is a perciform fish of genus Toxotes. As its name suggests, the scales of the smallscale archerfish are smaller than those of other archerfish. They reach a maximum length of...
, Toxotes microlepis Günther, 1860. - Western archerfish, Toxotes oligolepis BleekerPieter BleekerPieter Bleeker was a Dutch medical doctor and ichthyologist, famous for his work on the fishes of East Asia – Atlas Ichthyologique des Orientales Neerlandaises – which was published 1862–1877....
, 1876.
See also
- Two submarineSubmarineA submarine is a watercraft capable of independent operation below the surface of the water. It differs from a submersible, which has more limited underwater capability...
s of the United States NavyUnited States NavyThe United States Navy is the naval warfare service branch of the United States Armed Forces and one of the seven uniformed services of the United States. The U.S. Navy is the largest in the world; its battle fleet tonnage is greater than that of the next 13 largest navies combined. The U.S...
have been named USS ArcherfishUSS ArcherfishTwo submarines of the United States Navy have been named Archerfish, after the archerfish.* The , was a Balao-class submarine, commissioned in 1943 and decommissioned in 1946. When she was recommissioned in 1952 her name was changed to Archerfish....
, the first one holding the distinction of sinking the largest ship ever destroyed by a submarine, the 68,059-ton Japanese aircraft carrierAircraft carrierAn aircraft carrier is a warship designed with a primary mission of deploying and recovering aircraft, acting as a seagoing airbase. Aircraft carriers thus allow a naval force to project air power worldwide without having to depend on local bases for staging aircraft operations...
ShinanoJapanese aircraft carrier Shinanonamed after the ancient Shinano Province, was an aircraft carrier of the Imperial Japanese Navy during World War II. Initially laid down as the third of the battleships, Shinano′s partially complete hull was converted to an aircraft carrier in 1942, midway through construction. Over the next two...
, on November 29, 1944. - Projectile use by living systemsProjectile use by living systemsAlthough projectiles are commonly used in human conflict, projectile use by living systems other than humans is relatively rare.-Liquid projectiles:...