Poeciliidae

The Poeciliidae inhabit considerable areas of the American continent, favoring hard, alkaline, and sometimes even slightly brackish conditions where the water is rich in plant life and normally calm. This is a family of active, energetic fish, ideal for the beginner. They will accept any form of food, including small, live prey, but appreciate extra vegetable material.

The male is normally smaller than the female, though often more vividly colored. His anal fin, by a modification of the third, fourth and fifth rays, has developed into a gonopodium (see illustration), a tubiform copulatory organ, through which he deposits his milt (sperm) into the female's genital pore during a fairly brief pseudo-coupling. The female can then produce several successive broods separated by a few weeks without intervention by other males, a feature which distinguishes this family from the Goodeidae. A darkish patch on her belly - the gravid spot, near the genital pore -signals imminent spawning in a ripe female. The eggs hatch inside her ovary; she then immediately expels the fry, often still in a curled, foetal position. These are much bigger than the fry of oviparous (egg-laying) fish: they are able to swim and eat fine artificial food on birth. To encourage reproduction, raise the temperature by a few degrees; the female will then spawn every 3-4 weeks.

Sphenops Molly Gambusia HybridPoeciliidae

Poecilia latipinna

This is known as the saill should be kept in identical conditions to P. sphenops. (Both are popularly referred to as simply the molly or black molly.) The dorsal fin is both higher and longer then that of P. sphenops. The black lyretail variety is probably a hybrid of the two species, rather than a variety of one or the other. Size: 8 cm. •

Gambusia Mosquito Fish

• Gambusia affinis ft native of the southern United States, the spotted gambusia or mosquito fish has been widely introduced to tropical and temperate areas of the world. It is met in southern France, for instance, close to the Mediterranean coasts and even as far north as Bordeaux! These deliberate importationswere designed to re plagues of mosquitoes, since the voraciously fond of the aquatic lai sense, then, it is not a "true" aquanum fish, but it is very sturdy and spawns prolifically. You can raise it as live food for voracious predators like the Cichlids; or for those fish with a tendency to refuse artificial foods, like certain marine species, as it can survive a few minutes' immersion insalt water. Size: 5 cm.

• Poecilia sphenops (molly)

The common variety of short-finned molly or pointed-mouth molly has a silverv-nrav bnriv with varvinn rienraes of black spotting. The black variety is more popular with some enthusiasts. The molly prefers hard water, to which you can add 1 % seawater - or 1 teaspoonful of table salt to 10 liters of water. It is also a good idea to feed supplements of vegetable material. Size: 8 cm.

Yucaton Molly Fishes Yucatan Molly

• Poecilia velifera

The Yucatan sailfin molly has an overdeveloped dorsal fin. A black variety exists, but it is less common than the "gold" the latter is rather incongruously named since it is practically an albino, as its red eyes imply. Breeding is straightforward, and even easier if you raise the temperature a few degrees. The females can produce up to 100 fry. Size: 15 cm.

TRUE OR FALSE LIVEBEARERS?

The term "livebearer" or "viviparous" is applied to fish of the following families: Poeciliidae, Hemirhamphidae, and Goodeidae. Their fry are born live (already hatched), a phenomenon rare among fish. In actual fact, the descriptions are scientifically inexact in the case of the first two families: there is no anatomical connection between the egg and the mother fish as there is in certain sharks and in mammals. Only the Goodeidae can be classed as true livebearers, but aquarists commonly lump all three families together under this heading.

Poecilia reticulata

Guppy Varieties

Varieties of guppy, classified by dorsal fins

Poeciliareticulata

Even those who have never kept an aquarium will have heard of the guppy! Discovered in the middle of the 19th century, it is one of the most popular species owing to its uncomplicated breeding habits and the large number of available varieties, which are classified according to overall coloration and the shape of the caudal fin. The guppy prefers hard, alkaline conditions, but it is extremely tolerant. A female can produce up to 100 fry every 4 weeks if the temperature is raised to 27-28°C. Feral guppies are unspectacular in color, with sometimes one or two black patches, and the fins are of normal size. Size: 5 cm.

Varieties of guppy, classified by dorsal fins

Poeciliidae

Poecilia reticulata

Poecilia reticulata

Fin Variatus

Poecilia reticulata

Lyretail Guppy Colors

Poecilia reticulata

basic variety pointed-tail spadetail lyretail top sword basic variety pointed-tail spadetail lyretail top sword

POECILIIDAE

A LIVEBEARER FOR THE BEGINNER: THE PLATY

XIPHOPHORUSMACULATUS

In addition to the guppy, the platy orXiphophorus maculatus is an ideal starter fish. There are many varieties available commercially. They produce about 50 fry, and you can cross the platy with the swordtail and Xiphophorus variatus (variegated platy or "variatus"). Common varieties of platy are:

• wagtail: red or orange-yellow, with black fins;

• black: blue- or greenish-black metallic sheen;

• Simpson hi-fin: overdeveloped dorsal fin.

A LIVEBEARER FOR THE BEGINNER: THE PLATY

XIPHOPHORUSMACULATUS

Platy Simpson

• Xiphophorus helleri

Gold variety. Size: 15 cm

• Xiphophorus helleri

Gold variety. Size: 15 cm

Platy Varieties Pictures

Xiphophorus helleri

Wagtail variety. Size: 15 cm.

Xiphophorus helleri

Wagtail variety. Size: 15 cm.

Xiphophorus helleri

The photo opposite clearly shows why X. helleri is known as the swordtail. A very lively fish, it can leap out of the aquarium, and the male is sometimes truculent. Females do not have the "sword." The female can produce up to 200 fry and exhibits behavior very rare among fish and indeed all other animals: after one or two spawnings, she can undergo a spontaneous sex reversal, and function in all respects like a male! Size: 15 cm.

lower swordtail double swordtail flagtail delta fantail lower swordtail double swordtail flagtail delta fantail

FRESHWATER FISH Xiphophorusvariatus

The variegated platy has fewer varieties than X. maculatus, with which it can be crossed. The female can produce up to 100 fry. Size: 5 cm.

Double Swordtail PlattiesMontezuma Swordtail

•Xiphophorusmontezumae

This is the Montezuma swordtail. Most swordtails - the specimen illustrated here is a feral variety - have shorter "swords" than X. helleri. They are rarely sold commercially. Size: 5 cm.

VARIETIES OF SWORDTAIL

Swordtails are distinguished by their color and/or the shape of the finnage:

• green: more or less bright green, with a broken red line on each flank; probably closely related to the feral form;

• red: entirely red body, the commonest variety;

• tuxedo: red background, large black streak from back of head to caudal peduncle;

• black: in reality blue or green, with dark metallic sheen;

• Simpson (hi-fin): highly-developed dorsal fin;

• veiltail: all fins are larger than normal;

• lyretail: upper and lower sections of caudal fin prolonged by filaments.

Xiphophorus Helleri Copulatory

Xipho helleri

Xipho helleri

Green varietv. Size:

• Xipho helleri

Red veiltail variety. Size: 15 cm.

Xipho helleri

Simpson hi-fin variety Size: 15

Xipho helleri

Simpson hi-fin variety Size: 15

Poeciliidae

HEMIRHAMPHIDAE - GOODEIDAE

THE POECILIIDAE: CROSSES AND VARIETIES

There are very few aquarists who have seen, let alone owned, the wild stock from which captive varieties are descended. These varieties do not exist in Nature, but they are readily obtainable commercially. Some aquarists enter their prize specimens for shows, where they are judged on color, shape, and the development of the finnage. How many varieties are there? At the present time, there are five different color varieties of swordtail, plus another three for fin shape. Given that similar figures would also hold good for the platies, and that all species of Xiphophorus (swordtails, platies, variegated platies, etc.) can interbreed, the number of varieties becomes enormous; there's no way you'll remember them all! You sometimes hear aquarists remark that the present varieties, which have been patiently evolved through selection, are less hardy than earlier ones. Though the truth is somewhat more complex, beginners, who are encouraged to try these fish - mainly because they breed easily - may be slightly disappointed.

Different Color Platties

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  • osman girmay
    Why is platy fish curled?
    7 years ago

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