The Endler's Livebearer

Very few pet stores carry the Endler's, a beautiful, hardy relative of the guppy. Discovered by the aquarium industry as recently as 1975, these brightly colored, wild-strain fish are exciting and full of personality. Although currently somewhat uncommon for home aquarium displays, the Endler's liverbearer is quickly gaining in popularity.

Endler's livebearers are very similar to guppies, which are very close relatives. In fact, because the two species are able to interbreed and produce fertile offspring. Like the guppy, Endler's livebearers give birth to live young that are free-swimming within a matter of minutes or hours. Both fish varieties will eagerly partake in both interspecies and intraspecies breeding.

Guppies and Endler's livebearers differ in both appearance and behavior. The Endler's livebearer is characterized by its elongated gonopodium (the modified anal fin of male livebearers) and by its distinct color-band in the middle of its body. Endler's livebearers also have a wider variety of colors present on their bodies, and are smaller by comparison, weighing in at about the size of an average dwarf or feeder-guppy.

The Endler's livebearer also exhibits some different behaviors, tending to school with its own kind when individuals of the same species are present. Because of this difference in social behavior, Endler's livebearers and guppies do not generally cross-breed in the wild, even when they are cohabitating in the same natural environments.

The interbreeding of Endler's livebearers are standard guppies is a topic of debate among aquarists and enthusiasts. Endler's livebearers have naturally created a separate species, or at least subspecies, as a result of thousands of years of natural selection. Deliberate cross-breeding between the two livebearer varieties may weaken both gene pools and eliminate the natural adaptions made by each species.

Nevertheless, many breeders feel that it is justifiable to create hybrid strains of guppy and Endler's livebearer, because this strengthens and adds variety to both gene pools to make them suitable for the aquarium industry. Over time, the captive breeding and cross-breeding of the two species may help to eliminate the need for wild-caught individuals, which may protect wild Endler's livebearers.

The Endler's livebearer may gain in popularity in the coming years, or its traits may simply be added to the gene pools of standard guppies. While some aquarists are acting to eliminate the corss-breeding of the two species, it will most likely continue, even if only in captive, controlled populations.

Molly Fish Color Varieties

While the black molly remains the most popular and inexpensive color variety of molly fish, dozens of other varieties also exist. Because mollies are prolific and robust, breeders and enthusiasts have popularized several beautiful color strains of this brackish-water fish. As a molly enthusiast, I've enjoyed watching and breeding the dozens of varieties of molly that appear on the market. The genetic variability and eager breeding habits of the molly make it an excellent choice for anyone who is interested in fish genetics. The following molly color varieties are among the most popular commercially available types.

Wild Type Molly

In the wild, mollies have a dull green-gray coloration; however, more colorful color strains sometimes appear sporadically in the wild. Wild mollies tend to be hardier than their cultivated counterparts.

Black Molly

The most popular molly color variety on the market, these beautiful onyx fish carry a mutation similar to the melanistic gene responsible for a black panther's coloration. It rarely occurs in the wild and it was the first unusual color strain to be cultivated in captivity.

Gold Molly

Yellow-orange mollies, sometimes sold as gold or creamsicle mollies, are among the most visually stunning varieties of this fish. Geneticists and molly breeders refer to this mutation as xanthochromism; it is seen in many other species including dozens of cyprinids.

Gold Dust Molly

The increasingly popular "gold dust" molly occurs as a result of interbreeding between black and gold mollies. Because the two alleles are codominant--they both express themselves on the same individual-- the fish are usually black with golden patches.

Silver Molly

White or silver mollies come in two varieties: albino and leucistic. Albino mollies have pinkish or red eyes, whereas leucistic molllies have normal-hued eyes. Both have a dazzling pearl-like coloration.

Marble Molly

Because many molly genes are codominant, several color varieties combine multiple hues on one fish. Marble mollies result when silver and block mollies interbreed; they may have a marbled or piebald appearance.

Dalmation Molly

There are few major differences between a marble molly and a dalmation molly, but most breeders consider a fish to be dalmation if it has significantly more white on its body than black. Like marble mollies, dalmation mollies result from interbreeding between black and white varieties.

Calico Molly

Rarely, black, white and gold mollies will interbreed to create offspring with all three colors. These are considered to be calico, tortoiseshell or tricolor mollies and I find them to be the most beautiful domestic strain available.

Other rare molly color varieties include the red molly and blue molly, which are not true mollies-- rather, they are the result of extensive cross-breeding with platies and swordtails. These varieties are rarely sold in pet stores, but some private breeders sell them via the internet.

Platy Fact Sheet

Livebearing toothcarps like the platy are extremely popular among beginning fishkeepers. The platy fish is extremely hardy, inexpensive and easy to breed, and dozens of varieties exist. Platies were among the first fish that I kept when I first began fishkeeping, and they still remain one of my favorite species of ornamental fish.

These charming livebearers are easy to keep, but good care is still essential to help them thrive. This platy fish care sheet can help you establish a good home for your new fish.

Adult Size

An adult platy will usually grow to 1.5- 2 inches in length. Females are larger by about a half-inch.

Tank Size

Platy fish can thrive in relatively small tanks, but they should not be kept in anything less than ten gallons.

Social Behavior

Though not a true shoaling species, platy fish tend to do best in small groups. ideally, one male should be kept with two females. This prevents aggression between the boys.

Tank Mates

The platy is extremely peaceful and gets along well with other species. Do not keep platy fish with any species that is large or aggressive enough to harm them.

Life Span

Platy fish do not have particularly long lives; they rarely live more than two and a half to three years.

Diet

The platy is a true omnivore; it will eat fresh, frozen or flake food of any kind. Be sure to provide a varied diet.

Breeding

Platy fish are easy to breed-- in fact, most fishkeepers have a hard time stopping them. The young are free-swimming as soon as they are born, but the parents will usually eat them unless they are separated or have plenty of hiding spaces.

Water Parameters

A platy will do best at a pH between 7-8. Keep ammonia levels undetectable and nitrate levels below 25 ppm. Platy fish can tolerate lightly brackish water if they are acclimated gradually.

Temperature

Platy fish do not require a heater. Although the water temperature should remain stable, these fish can thrive at any temperature between 65-80 degrees.

Variations

Dozens, if not hundreds, of cultivated varities of platy fish exist. Red-wag, moon, sunset, Mickey Mouse, rainbow, calico, black, blue, tuxedo, albino, tiger and marble varieties are just a few. Many of these are the result of selective cross-breeding with related species like the molly and the swordtail.

Swordtail Fact Sheet

The swordtail, a showy livebearer, is one of the most popular freshwater fish for beginners to the hobby. Over the course of ten years of fishkeeping, I have enjoyed keeping swordtails and their close relative, the platy. While they are extremely easy to care for, swordtail fish should not be overlooked by veteran fishkeepers-- they provide plenty of entertainment and beauty.

While swordtails are relatively easy to care for, they require good water conditions in order to truly thrive. If you keep your swordtail fish in good conditions, you'll be pleased by their active personalities and beautiful appearance.

Adult Size

Swordtails are one of the largest livebearing toothcarps. An adult can grow to five inches or more.

Tank Size

A trio of swordtails might be kept in a ten-gallon tank if the water is kept immaculately clean. Otherwise, twenty gallons is the bare-minimum for this active species.

Social Behavior

Swordtail fish do not school together, but they do require some degree of social interaction. Keep swordtails in groups of three or more. Alternatively, keep a single swordtail with two or more other livebearers, such as mollies or platy fish.

Tank Mates

Predatory fish seem to love the taste of swordtails. Avoid keeping them with large predators. Swordtails may bully petite livebearers like the guppy, and nippy fish like the rosy barb tend to bite the males' showy tails. Otherwise, swordtail fish can tolerate a wide range of tankmates.

Life Span

A well-kept sword tail can live to be up to five years old. Two to three years is more common in captivity.

Diet

Swordtails are omnivores, but their diet should include plenty of veggies. Flake, frozen and live food are all appropriate. Some stores offer livebearer flakes designed for these veggie-crazy fish.

Breeding

You will have no difficulty breeding swordtails; you're more likely to have trouble stopping them from breeding. Females will give birth to live young every four weeks. If the parents aren't removed from the tank, they will usually eat their young.

Water Parameters

Swordtails can live in a wide variety of water conditions, and they can endure unusually high levels of pollutants. Maintain a pH between 7-8. Swordtails can tolerate nitrate levels up to 30 ppm and ammonia levels up to 2 ppm.

Temperature

Swordtails can live without a heater if your home stays relatively warm. Keep the temperature between 70-82 degrees at all times.

Variations

Breeders have created dozens of unique varieties of swordtail fish, mostly by cross-breeding them selectively with related species. Pet stores may offer black, tuxedo, gold, neon, spotted, lyretail, albino, silver, red and blue swordtail varieties.