Poecilia sphenops

From Wikipedia, the free encyclopedia
Jump to: navigation, search
Common Molly
Poecilia sphenops.jpg
Male Common Molly
Scientific classification
Kingdom: Animalia
Phylum: Chordata
Class: Actinopterygii
Order: Cyprinodontiformes
Family: Poeciliidaetropical
Genus: Poecilia
Species: P. sphenops
Binomial name
Poecilia sphenops
(Valenciennes, 1846)
Female Black Molly

Poecilia sphenops is a species of fish, of the genus Poecilia, known under the common name molly; to distinguish it from its congeners, it is sometimes called short-finned molly or common molly. They inhabit fresh water streams and coastal brackish and marine waters of Mexico. The wild-type fish are a dull silvery color, often sprinkled black all over. The common molly can produce fertile hybrids with many Poecilia species, most importantly the sailfin molly. The male black mollies generally tend to be mildly aggressive.

Mollies rank as one of the most popular feeder fish due to high growth rate, birth size, reproduction,and brood number.

Biology[edit]

Contrary to popular belief, this species of fish is actually a freshwater species, spending little time in brackish water before swimming back to their freshwater biotope. However, fish of the same species have been found in coastal sea waters, brackish swamps and freshwater streams, living and breeding. Mollies appear to be a hardy and highly adaptable species (this has been diluted over years of interbreeding in tank-bred specimens).

Size[edit]

Standard size of male fish is 3.2″ (8cm) and female fish is 4.8″ (12cm).

Varieties[edit]

Selective breeding over centuries has produced several color variations and different body shapes.

Short-Finned Molly or Common Molly: They inhabit fresh water streams and coastal brackish and marine waters of Mexico. The wild-type fish are a dull silvery color, often sprinkled black all over. The common molly can produce fertile hybrids with many Poecilia species, most importantly the sailfin molly. The wild form is in fact quite rarely kept, as it has a rather plain silvery coloration suffused with brown and green hues.

Black Molly or Midnight Molly: This variety actually originated from hybrids between Poecilia sphenops and the sailfin molly. Due to genomic recombination, F1 hybrids often display novel and bizarre fin shapes. It is a melanistic breed which are black all over. It is one of the most well-known aquarium fishes and nearly as easy to keep and prolific as guppies.

Golden Molly: Nicknamed the "24 karat".

Balloon Molly: This fish has a deformed spine due to a genetic defect that gives it its appearance. Through Selective breeding, similar to many dog breeds such as pugs, it is now widely available. Balloon mollies can still reproduce and live a normal life comparable to that of other mollies, but it has garnered controversy due to the belief that its defect gives it a shortened lifespan and a susceptibility to health problems.

Lyretail: A breed with an altered caudal fin structure.

sailfin molly: A breed with an altered caudal fin structure.

Dalmatian Molly: A silver colored breed with black speckles.

References[edit]