Southern platyfish
Encyclopedia
The southern platyfish, common platy or moonfish (Xiphophorus maculatus) is a species
of freshwater fish
in family
Poecilidae of order
Cyprinodontiformes
. A live-bearer
, it is closely related to the green swordtail
(X. helleri) and can interbreed with it. It is native to an area of North
and Central America
stretching from Veracruz
, Mexico
, to northern Belize
.
The southern platyfish grows to a maximum overall length of 6.0 cm (2.4 in). Sexual dimorphism
is slight, the male's caudal fin being more pointed. The anal fin of the male fish has evolved into a gonopodium, a stick-shaped organ used for reproduction. The female southern platyfish's anal fin is fan shaped. Wild varieties are drab in coloration, lacking the distinctive dark lateral line common to many Xiphophorus species.
X. maculatus prefers slow-moving waters of canals, ditches, and warm springs. Omnivorous, its diet includes both plants and small crustacean
s, insect
s, and annelid
worms.
Breeders have developed a multitude of color varieties (e.g. orange, red, yellow, red/black, and black/white) which are common aquarium
fish for hobbyists.
The southern platyfish is commonly known simply as the platy (pl. platys or platies), from the fish's original generic
name, Platypoecilus.
The southern platyfish has been released probably due to fish farm or aquarium releases. Specimens in Louisiana were collected near a tropical fish farm. Southern platys, and other introduced poeciliids, have been implicated in the decline of native damselflies on Oahu, Hawaii. Often the distributions of the damselflies and introduced fishes were found to be mutually exclusive, probably resulting from predation of the fish on the insects.
, a water hardness of 9.0–19.0 dGH
, and a temperature range of 18 to 25°C (64–77°F).
In captivity, they reach maturity in three to four months, and breed readily, the females giving birth to about 20-40 young at a time.
The fish commonly sold in pet shops is not a pure strain of X. maculatus, but is a hybrid between X. hellerii and X. maculatus. In general, if the male has a sword-shaped tail, they are called swordtails. Otherwise, they are labeled platy. Color and fin shape vary wildly in the aquarium trade.
A common statement in the trade is that it is harder to stop them breeding than to make them do so, with "surprise" fry appearing in community tanks regularly.
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
Freshwater fish
Freshwater fish are fish that spend some or all of their lives in freshwater, such as rivers and lakes, with a salinity of less than 0.05%. These environments differ from marine conditions in many ways, the most obvious being the difference in levels of salinity...
in 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...
Poecilidae 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...
. A live-bearer
Live-bearing aquarium fish
Live-bearing aquarium fish, often simply called livebearers, are fish that retain the eggs inside the body and give birth to live, free-swimming young.-Common aquarium livebearers:...
, it is closely related to the green swordtail
Green swordtail
The green swordtail is a species of freshwater fish in family Poeciliidae of order Cyprinodontiformes. A live-bearer, it is closely related to the southern platyfish or "platy" and can crossbreed with it...
(X. helleri) and can interbreed with it. It is native to an area of North
North America
North America is a continent wholly within the Northern Hemisphere and almost wholly within the Western Hemisphere. It is also considered a northern subcontinent of the Americas...
and Central America
Central America
Central America is the central geographic region of the Americas. It is the southernmost, isthmian portion of the North American continent, which connects with South America on the southeast. When considered part of the unified continental model, it is considered a subcontinent...
stretching from Veracruz
Veracruz
Veracruz, formally Veracruz de Ignacio de la Llave officially Estado Libre y Soberano de Veracruz de Ignacio de la Llave , is one of the 31 states that, along with the Federal District, comprise the 32 federative entities of Mexico. It is divided in 212 municipalities and its capital city is...
, Mexico
Mexico
The United Mexican States , commonly known as Mexico , is a federal constitutional republic in North America. It is bordered on the north by the United States; on the south and west by the Pacific Ocean; on the southeast by Guatemala, Belize, and the Caribbean Sea; and on the east by the Gulf of...
, to northern Belize
Belize
Belize is a constitutional monarchy and the northernmost country in Central America. Belize has a diverse society, comprising many cultures and languages. Even though Kriol and Spanish are spoken among the population, Belize is the only country in Central America where English is the official...
.
The southern platyfish grows to a maximum overall length of 6.0 cm (2.4 in). 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 slight, the male's caudal fin being more pointed. The anal fin of the male fish has evolved into a gonopodium, a stick-shaped organ used for reproduction. The female southern platyfish's anal fin is fan shaped. Wild varieties are drab in coloration, lacking the distinctive dark lateral line common to many Xiphophorus species.
X. maculatus prefers slow-moving waters of canals, ditches, and warm springs. Omnivorous, its diet includes both plants and small crustacean
Crustacean
Crustaceans form a very large group of arthropods, usually treated as a subphylum, which includes such familiar animals as crabs, lobsters, crayfish, shrimp, krill and barnacles. The 50,000 described species range in size from Stygotantulus stocki at , to the Japanese spider crab with a leg span...
s, 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 annelid
Annelid
The annelids , formally called Annelida , are a large phylum of segmented worms, with over 17,000 modern species including ragworms, earthworms and leeches...
worms.
Breeders have developed a multitude of color varieties (e.g. orange, red, yellow, red/black, and black/white) which are common aquarium
Aquarium
An aquarium is a vivarium consisting of at least one transparent side in which water-dwelling plants or animals are kept. Fishkeepers use aquaria to keep fish, invertebrates, amphibians, marine mammals, turtles, and aquatic plants...
fish for hobbyists.
The southern platyfish is commonly known simply as the platy (pl. platys or platies), from the fish's original 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, Platypoecilus.
Nonindigenous occurrences
This species has been recorded from Orange County, California, near Westminster; near a fish farm in Conejos County and the South Platte drainage, Colorado; several counties in Florida; Hawaii; an unnamed tributary to Big Branch Bayou in Lacombe, Louisiana; Beaverhead Rock Pond (Madison County), Montana; Clark County, Nevada; and Texas. It has also been collected in the Loiza drainage near Loiza Reservoir, Quebrada Honda, and Rio Abajo Forest Station north of Utuado in Puerto Rico.The southern platyfish has been released probably due to fish farm or aquarium releases. Specimens in Louisiana were collected near a tropical fish farm. Southern platys, and other introduced poeciliids, have been implicated in the decline of native damselflies on Oahu, Hawaii. Often the distributions of the damselflies and introduced fishes were found to be mutually exclusive, probably resulting from predation of the fish on the insects.
In the aquarium
Platys are easy to keep and well suited to a community aquarium. They prefer water with a 7.0–8.0 pHPH
In chemistry, pH is a measure of the acidity or basicity of an aqueous solution. Pure water is said to be neutral, with a pH close to 7.0 at . Solutions with a pH less than 7 are said to be acidic and solutions with a pH greater than 7 are basic or alkaline...
, a water hardness of 9.0–19.0 dGH
DGH
Degrees of general hardness is a unit of water hardness, specifically of general hardness.General hardness is a measure of the concentration of metal divalent ions such as calcium and magnesium per volume of water...
, and a temperature range of 18 to 25°C (64–77°F).
In captivity, they reach maturity in three to four months, and breed readily, the females giving birth to about 20-40 young at a time.
The fish commonly sold in pet shops is not a pure strain of X. maculatus, but is a hybrid between X. hellerii and X. maculatus. In general, if the male has a sword-shaped tail, they are called swordtails. Otherwise, they are labeled platy. Color and fin shape vary wildly in the aquarium trade.
A common statement in the trade is that it is harder to stop them breeding than to make them do so, with "surprise" fry appearing in community tanks regularly.