Mosquitofish
Encyclopedia
The mosquitofish is a species
of freshwater fish, also commonly, if ambiguously, known by its generic
name, gambusia. It is sometimes called the western mosquitofish, to distinguish it from the eastern mosquitofish
(G. holbrooki). It is a member of the family
Poeciliidae
of order
Cyprinodontiformes
. The genus name Gambusia is derived from the Cuban Spanish
term gambusino, meaning "useless".
, which belong to the same taxonomic family. Sexual dimorphism
is pronounced; mature females reach a maximum overall length of 7 centimetres (2.8 in), while males reach only 4 centimetres (1.6 in). Sexual dimorphism is also seen in the physiological structures of the body. The anal fins on adult females resemble the dorsal fin
s, while the anal fins of adult males are pointed. This pointed fin, referred to as a gonopodium, is used to deposit sperm
inside the female. Other similar species of G. affinis include Poecilia latipinna, Poecilia reticulata, Xiphophorus maculatus, and is commonly misconceived as the eastern mosquitofish
.
of the Gulf of Mexico
, where they feed readily on the aquatic larva
l and pupa
l stages of mosquitoes. Mosquitofish can survive relatively ihospitable environments, and are resilient to low oxygen concentrations, high salt concentrations (up to twice that of sea water), and temperatures up to 42° Celsius (for short periods). For these reasons, this species may now be the most widespread freshwater
fish in the world, having been introduced as a biocontrol
to tropical and temperate
countries in both hemispheres, and then spreading further both naturally and through even further introductions. The majority of these introductions were ill-advised; in most countries where mosquitofish have been introduced, endemic fish species were proven to already provide maximal mosquito control, and the introduction of mosquitofish has been both unnecessary and highly damaging to endemic fish and other endemic aquatic life. In Australia
, G. holbrooki has caused great damage to indigenous fish and frog species. For example, it is considered responsible for the extinction of rainbowfish
in subtropical streams around Brisbane
. However, in some areas, introduction of mosquitofish did help in eradicating malaria
, for example, in South America and in the south of Russia and Ukraine in the 1920s–1950s, particularly at the Black Sea
coast near Sochi
, Russia
. A monument to the fish was raised there in 2010 in recognition of that fact.
The diet of mosquitofish mostly consists of zooplankton
, small insects and insect larvae, and detritus
material. Mosquitofish feed on mosquito larvae at all stages of life. Adult female mosquitofish can consume in one day hundreds of mosquito larvae. Maximum consumption rate in a day by one mosquitofish has been observed to be from 42%-167% of its own body weight.
Under favorable conditions, mosquitofish live two to three years. Estimates of their breeding potential have therefore demonstrated an incredible ability for this species to multiply and dominate new habitats into which they have been introduced. Their success in a new environment is almost guaranteed by their rapid maturation, by breeding several times a year, and producing broods of around 50 advanced live young. Individual populations have been recorded expanding from 7,000 to 120,000 in five months.
Species
In biology, a species is one of the basic units of biological classification and a taxonomic rank. A species is often defined as a group of organisms capable of interbreeding and producing fertile offspring. While in many cases this definition is adequate, more precise or differing measures are...
of freshwater fish, also commonly, if ambiguously, known by its generic
Genus
In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...
name, gambusia. It is sometimes called the western mosquitofish, to distinguish it from the eastern mosquitofish
Eastern mosquitofish
The eastern mosquitofish, Gambusia holbrooki, is a species of freshwater fish that is closely related to the western mosquitofish, Gambusia affinis. It is a member of the family Poeciliidae of order Cyprinodontiformes...
(G. holbrooki). It is a member of the family
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...
Poeciliidae
Poeciliidae
Poeciliidae is a family of fresh-water fish which are live-bearing aquarium fish . They belong to the order Cyprinodontiformes, tooth-carps, and include well-known aquarium fish such as the guppy, molly, platy, and swordtail...
of order
Order (biology)
In scientific classification used in biology, the order is# a taxonomic rank used in the classification of organisms. Other well-known ranks are life, domain, kingdom, phylum, class, family, genus, and species, with order fitting in between class and family...
Cyprinodontiformes
Cyprinodontiformes
The Cyprinodontiformes is an order of ray-finned fish, comprising mostly small, fresh-water fish. Many popular aquarium fish, such as killifish and live-bearers, are included. They are closely related to the Atheriniformes and are occasionally included with them...
. The genus name Gambusia is derived from the Cuban Spanish
Cuban Spanish
Cuban Spanish is the dialect of the Spanish language as it is spoken in Cuba. As a Caribbean dialect, Cuban Spanish shares a number of features with nearby varieties, including coda deletion, seseo, and debuccalization.-Overview:...
term gambusino, meaning "useless".
Description
Mosquitofish are small and stout, dull grey, and quite robust, with a rounded tail and a terminal and upward-pointing mouth adapted for feeding at the water's surface. In these features and their small size they resemble the tropical guppiesGuppy
The guppy , also known as the millionfish, is one of the most popular freshwater aquarium fish species in the world. It is a small member of the Poeciliidae family [females long, males long] and like all other members of the family, is live-bearing....
, which belong to the same taxonomic family. Sexual dimorphism
Sexual dimorphism
Sexual dimorphism is a phenotypic difference between males and females of the same species. Examples of such differences include differences in morphology, ornamentation, and behavior.-Examples:-Ornamentation / coloration:...
is pronounced; mature females reach a maximum overall length of 7 centimetres (2.8 in), while males reach only 4 centimetres (1.6 in). Sexual dimorphism is also seen in the physiological structures of the body. The anal fins on adult females resemble 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...
s, while the anal fins of adult males are pointed. This pointed fin, referred to as a gonopodium, is used to deposit sperm
Sperm
The term sperm is derived from the Greek word sperma and refers to the male reproductive cells. In the types of sexual reproduction known as anisogamy and oogamy, there is a marked difference in the size of the gametes with the smaller one being termed the "male" or sperm cell...
inside the female. Other similar species of G. affinis include Poecilia latipinna, Poecilia reticulata, Xiphophorus maculatus, and is commonly misconceived as the eastern mosquitofish
Eastern mosquitofish
The eastern mosquitofish, Gambusia holbrooki, is a species of freshwater fish that is closely related to the western mosquitofish, Gambusia affinis. It is a member of the family Poeciliidae of order Cyprinodontiformes...
.
Naming and Taxonomy
The common name of the Gambusia affinis is the mosquitofish. This name is derived from the fact that it eats large amounts of mosquito larve.Habitat
Mosquitofish are indigenous to the watershedDrainage basin
A drainage basin is an extent or an area of land where surface water from rain and melting snow or ice converges to a single point, usually the exit of the basin, where the waters join another waterbody, such as a river, lake, reservoir, estuary, wetland, sea, or ocean...
of the Gulf of Mexico
Gulf of Mexico
The Gulf of Mexico is a partially landlocked ocean basin largely surrounded by the North American continent and the island of Cuba. It is bounded on the northeast, north and northwest by the Gulf Coast of the United States, on the southwest and south by Mexico, and on the southeast by Cuba. In...
, where they feed readily on the aquatic larva
Larva
A larva is a distinct juvenile form many animals undergo before metamorphosis into adults. Animals with indirect development such as insects, amphibians, or cnidarians typically have a larval phase of their life cycle...
l and pupa
Pupa
A pupa is the life stage of some insects undergoing transformation. The pupal stage is found only in holometabolous insects, those that undergo a complete metamorphosis, going through four life stages; embryo, larva, pupa and imago...
l stages of mosquitoes. Mosquitofish can survive relatively ihospitable environments, and are resilient to low oxygen concentrations, high salt concentrations (up to twice that of sea water), and temperatures up to 42° Celsius (for short periods). For these reasons, this species may now be the most widespread freshwater
Freshwater
Fresh water is naturally occurring water on the Earth's surface in ice sheets, ice caps, glaciers, bogs, ponds, lakes, rivers and streams, and underground as groundwater in aquifers and underground streams. Fresh water is generally characterized by having low concentrations of dissolved salts and...
fish in the world, having been introduced as a biocontrol
BioControl
BioControl is a peer-reviewed scientific journal published by Springer Science+Business Media covering all aspects of basic and applied research in biological control of invertebrate, vertebrate, and weed pests, and plant diseases. The journal was established in 1956 as Entomophaga and published by...
to tropical and temperate
Temperate
In geography, temperate or tepid latitudes of the globe lie between the tropics and the polar circles. The changes in these regions between summer and winter are generally relatively moderate, rather than extreme hot or cold...
countries in both hemispheres, and then spreading further both naturally and through even further introductions. The majority of these introductions were ill-advised; in most countries where mosquitofish have been introduced, endemic fish species were proven to already provide maximal mosquito control, and the introduction of mosquitofish has been both unnecessary and highly damaging to endemic fish and other endemic aquatic life. In 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...
, G. holbrooki has caused great damage to indigenous fish and frog species. For example, it is considered responsible for the extinction of rainbowfish
Rainbowfish
The rainbowfish are a family of small, colourful, freshwater fish that are found in northern and eastern Australia and New Guinea and in the Southeast Asian islands....
in subtropical streams around Brisbane
Brisbane
Brisbane is the capital and most populous city in the Australian state of Queensland and the third most populous city in Australia. Brisbane's metropolitan area has a population of over 2 million, and the South East Queensland urban conurbation, centred around Brisbane, encompasses a population of...
. However, in some areas, introduction of mosquitofish did help in eradicating malaria
Malaria
Malaria is a mosquito-borne infectious disease of humans and other animals caused by eukaryotic protists of the genus Plasmodium. The disease results from the multiplication of Plasmodium parasites within red blood cells, causing symptoms that typically include fever and headache, in severe cases...
, for example, in South America and in the south of Russia and Ukraine in the 1920s–1950s, particularly at the Black Sea
Black Sea
The Black Sea is bounded by Europe, Anatolia and the Caucasus and is ultimately connected to the Atlantic Ocean via the Mediterranean and the Aegean seas and various straits. The Bosphorus strait connects it to the Sea of Marmara, and the strait of the Dardanelles connects that sea to the Aegean...
coast near Sochi
History of Sochi
The area of the Russian city of Sochi was populated more than 100,000 years by ancient people of Asia Minor migrating through Colchis . Ancient Greeks sailed to the region via the Black Sea in the 5th–6th centuries BC and encountered the Maeotae, Sindi, Cercetae, Zygii and other local tribes...
, Russia
Russia
Russia or , officially known as both Russia and the Russian Federation , is a country in northern Eurasia. It is a federal semi-presidential republic, comprising 83 federal subjects...
. A monument to the fish was raised there in 2010 in recognition of that fact.
Diet
Zooplankton
Zooplankton are heterotrophic plankton. Plankton are organisms drifting in oceans, seas, and bodies of fresh water. The word "zooplankton" is derived from the Greek zoon , meaning "animal", and , meaning "wanderer" or "drifter"...
, small insects and insect larvae, and detritus
Detritus
Detritus is a biological term used to describe dead or waste organic material.Detritus may also refer to:* Detritus , a geological term used to describe the particles of rock produced by weathering...
material. Mosquitofish feed on mosquito larvae at all stages of life. Adult female mosquitofish can consume in one day hundreds of mosquito larvae. Maximum consumption rate in a day by one mosquitofish has been observed to be from 42%-167% of its own body weight.
Environmental Impacts
Mosquitofish were intentionally introduced in many areas with large mosquito populations so that they might decrease the population of mosquitoes by eating the mosquito larvae. Their presence, however, has harmed some of the native species in these areas. Mosquitofish have been known to kill or injure other small fish by their aggressive behaviour and otherwise harm them through competition. Mosquitofish are now considered just slightly better at eating mosquitoes than at destroying other aquatic species.Reproduction
Female mosquitofish can reach sexual maturity in only six to eight weeks, and they may bear three to four broods in a single season. The first may number only a dozen, but later broods expand to 60 to 100 offspring. Females store sperm in their reproductive tracts for up to two months and give birth to live offspring. Live-bearing gives their young a much higher survival rate than in most species of egg-laying fish, which typically suffer from egg predation.Under favorable conditions, mosquitofish live two to three years. Estimates of their breeding potential have therefore demonstrated an incredible ability for this species to multiply and dominate new habitats into which they have been introduced. Their success in a new environment is almost guaranteed by their rapid maturation, by breeding several times a year, and producing broods of around 50 advanced live young. Individual populations have been recorded expanding from 7,000 to 120,000 in five months.
External links
- FishBaseFishBaseFishBase is a comprehensive database of information about fish species . It is the largest and most extensively accessed online database on adult finfish on the web...
: - ITISItisItis may refer to* Integrated Taxonomic Information System, a partnership designed to provide consistent and reliable information on the taxonomy of biological species...
: Gambusia affinis - Using Mosquitofish to Control Mosquito Larvae at About.comAbout.comAbout.com is an online source for original information and advice. It is written in English, and is aimed primarily at North Americans. It is owned by The New York Times Company....
- Gambusia Control Homepage