Poecilia velifera
From Wikipedia, the free encyclopedia
| Yucatan molly | ||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
 |
||||||||||||||
| Scientific classification | ||||||||||||||
|
||||||||||||||
| Binomial name | ||||||||||||||
| Poecilia velifera (Regan, 1914) |
Poecilia velifera, the Yucatan Molly, lives in coastal waters of the Yucatan peninsula. These live-bearer (Poeciliidae) fish are particularly well known for both the extreme size variation among males, and the sexual dimorphism between males and females in both body shape and behavior.
It is outwardly similar to the sailfin molly, P. latipinna, though larger overall and with a higher and longer dorsal fin in males. Full-grown fish are usually larger than 10 cm/4 in, though especially captive-bred individuals grow only to the size of sailfin mollies. The dorsal fins are the most distinctive character for telling the species apart: Those of the Yucatan molly have nearly 20 fin rays, counting where the fin meets the back, whereas the sailfin molly has less than 15 (intermediate numbers may indicate hybrids).
If the males spread their dorsal fin in display, these have a distinct fan- or trapezoid shape, with the upper edge being distinctly longer than the lower. The height of the dorsal fin, measured at the posterior edge, is a bit larger than the height of the tail.
[edit] Common names
Yucatan molly, "Sailfin molly" (erroneous) (English), Segelkärpfling (German), Hoogvinkarper Dutch, Molinezja żaglopłetwa (Polish), セイルフィン モーリー (seirufuin mōrī, Japanese) and molliénésie á voilure or simply "molly voile" (French).
Some names of the Yucatan molly - such as "Segelkärpfling" or the specific name velifera - contain an element signifying "sail", aggravating the confusion with the sailfin molly. The French terms are used for both species indiscriminately, as is the Japanese name (which is simply the Japanized form of "sailfin molly").
[edit] In the aquarium
Especially small strains are suitable for keeping in an aquarium. However, this fish is not as easy to keep as the sailfin molly, let alone the P. sphenops black molly. They need spacious tanks with well-aerated, slightly brackish[1] water to thrive. They are able to withstand higher temperatures than most pet fish. Although they can survive over 30° for prolonged periods of time if other conditioins are good, temperatures should be kept between 25 and 30°. Direct sunlight and an ample supply of plant food such as (organic) lettuce, peas, or certain algae are necessary for optimal health; in subtropical areas they can be kept outside in unheated tanks in the summer; in temperate zones this can be tried too but a backup heating is probably a good idea.
They are bred like other mollies; in line with their general requirements, this is somewhat more difficult than in related species. It is especially hard to get males to grow their spectacular fins. Professional breeders often separate males and females in winter, so that they are eager to breed in spring. Young can then - climate permitting - grow up in spacious outdoor basins during summer.
Like other Poecilia, they are prone to hybridization with their relatives. Not infrequently, it is attempted to cross them with the sailfin molly in an attempt to breed a hardier fish. This is generally not very successful and in any case should not be attempted, as purebred Yucatan mollies are often quite hard to find, and hybrids won't have as massive dorsal fins as these. Several color variants are also available; these usually do not attain the large size of wild-type fish and may have been crossbred with P. latipinna.
[edit] References
- ^ 1 teaspoon to 1 tablespoon sea salt per 10 liters with the higher amount being suitable for wild strains, the lower for color variants. Note that many popular freshwater fish - such as tetras and danionins - will become sick and may die in brackish water.
[edit] External links
- akvariumas.lt: Image of male displaying top female.
