Amazon molly

The Amazon molly (Poecilia formosa) is a freshwater fish native to the warm waters of northeastern Mexico and the southern parts of the U.S. state of Texas.

[11] The hybridization event that resulted in the formation of the species Poecilia formosa is believed to have occurred near Tampico, Mexico.

P. formosa was able to reproduce by using male P. latipinna as sperm donors, which allowed their population in the San Marcos to grow.

[14] Ecological Niche Modeling The geographical range of the Amazon molly has been the primary research question of multiple scientific studies.

[15] P. mexicana's range extends from the Rio San Fernando River's drainage in northeastern Mexico southward into Costa Rica and Honduras.

[16] In a study completed in 2010, researchers were able to identify two probable causes for the truncation of the habitat of the Amazon molly using a method called Ecological Niche Modeling] (ENM).

[17] At the northern limit of their native range, it was found that, even though sperm donor species were available, the environmental conditions were not suitable enough for the Amazon molly to thrive.

Additionally, ENM found that the only suitable habitat not already occupied by the Amazon molly is in south Florida.

This means that females must mate with a male of a closely related species, but the sperm only triggers reproduction and is not incorporated into the already diploid egg cells the mother is carrying (except in extraordinary circumstances).

In nature, the Amazon molly typically mates with a male from one of four different species, either P. latipinna, P. mexicana, P. latipunctata, or occasionally P.

[24] The Amazon molly reaches sexual maturity one to six months after birth, and typically has a brood between 60 and 100 fry (young) being delivered every 30–40 days.

The wide variability in maturity dates and brood sizes is a result of genetic heritage, varying temperatures, and food availability.

They become sexually mature faster and produce larger broods in warm (approximately 27 °C or 80 °F) water that provides an overabundance of food.

Side-view of Poecilia formosa showcasing the silver coloration and spots along the side of the body
Range of Poecilia formosa by the IUCN Red List. The orange region represents its natural range, the purple region its introduced range, and the grey region its range of unknown origin (either natural or introduced).
Results from Ecological Niche Modeling. a) Poecilia formosa, b) Poecilia latipinna, and c) Poecilia mexicana. This figure shows how the natural range of the Amazon molly lies in between the ranges of its parent species.
There are four stages in the reproduction of the Amazon molly. In the first step, there is a diploid cell that is activated by a sperm cell but does not incorporate the genetic makeup of the sperm. The second step shows the copying of the two single chromosomes to make two doubled chromosomes. In the third step, the two chromosomes are being pulled apart to opposite sides of the cell. In the fourth and final step, there are two daughter cells, each with two single chromosomes, an exact replica of the mother cell.
The Amazon molly reproduces through gynogenesis. This image shows that the genetic material of the male is not incorporated into the offspring of the female. And the daughter cells produced are copies of the mother cell. [ 25 ]