Guppy - Poecilia reticulata

Scientific Name : Poecilia reticulata

Common Names : Fancy Guppy, Millions Fish, Rainbow Fish

Origin : Originally from an island northeast of South America. They are produced largely on asiatic farms these days.

Care Level : Easy, good for freshwater beginners when you have only one gender. This fish will breed easily in your tank if you plan on keeping males and females in the same tank.

Size : 2 inches (5 cm) - The majority of males reach 2 inches in length. They are much more colorful than the females, generally with larger dorsal fins and caudal fins. Female fancy guppies tend to be 2.5 inches in length.

pH : 7 - 8, harder water rather than softer, and slightly to moderately alkaline

Temperature : 66°F - 84°F (19°C - 29°C)

Water Hardness : 10° to 20° dH,

Lifespan : 3 - 5 years

Origin / Habitat : Central America

Temperament / Behavior : This is a mostly peaceful and hardy fish that is good for beginners. Male guppies can get aggressive with other male guppies.

Keeping them in an aquarium with a hood might be necessary since keepers have reported that their guppies have jumped out of the tank! I had to do some research on this because I had never heard nor seen them jumping. Sure enough, they do with the hypothesis being that they do it to reach all available habitat in Trinidad's mountain streams, which is where they originate. Evolution is amazing.

Breeding : Guppies are livebearers and are not very hard to breed. If you have males and females, chances are you will eventually have babies. Parents will eat their young if not separated. When presented with multiple females to breed with, males seem to prefer the larger females. Read the breeding guppies article for more information if you have a pregnant livebearer or fry.
If you want to try and raise the fry look into investing in a breeding box or breeder net like these:

Breeding Box or Breeding Net

From the caresheet on the forum:
The females are larger around the abdominal area, with the tell-tell purple cresent moon shape in the area directly above the vent. The vent being the opening in which waste is excreted as well as fry are dropped from. Purple cresent moon, also referred to as gravid area, denotes the containment of fetii, or developing baby fish.

Gestation period for poecilia reticulata averages 28-32 days depending on several factors. Water temperature, population density, availability of hiding places, quality of food, stress level, and other species in the tank all can be contributing factors to gestation period's length.

80-82 degrees farenheit water temperature has been known to cause a shorter gestation period. Population density, lack of availability of hiding places, and differing species in the tank all contribute to stress level, which can prolong gestation period, or holding of fry.

Fry become identifiable at about three weeks of age, given proper conditions. Then become reproductively mature around 3 months of age. Females that begin spawning at 3 months of age will have small spawns, but get progressively larger as the fish ages, until about a year of age. At one year of age they will hold steady for a few months and then begin to decline in fry per spawn, until they stop spawning all together. Males will begin breeding as early as 45 days, and continue until death for the most part.

Line breeding, or inbreeding, is often used to set desired traits. Line breeding is defined as breeding fish and their offspring back to each other, so that specific desired (desired by the human in control of breeding) traits become the dominant traits in any offspring of the fish. Generally when line breeding, new, unrelated stock needs to be added no less frequently than every 4th generation.

We've seen some adults learn not to eat their fry, some not have the issue at all, and some that we have agreed will never learn. We theorize the eatting of fry to be strain specific. Any of our primarily black guppy strains eat their fry everytime they have the chance. We've had a cobra strain learn not to eat their fry, much the same way angelfish learn. Of the strains that do not eat their fry, the mothers seem to keep an eye on them for several months, or until they become mature. Females have been seen to go as far as to defend the younger juveniles from adult males in our tanks. The defending was seen more in the platinum or pastel strains than any other.

Aquarium Size : 10 gallon or larger.

Tank Mates : Many, given their peaceful nature.

Diseases : Freshwater Fish Disease - Diagnose, Symptoms and Treatment. Guppies can easily get finrot so keep your water parameters in check and the water very clean via lots of partial water changes.

Diet / Foods : Give them flakes, freeze dried and live foods. Vary their diet for optimum colors and health. Good quality well balanced foods would be a positive, whereas low quality foods could put them in an imbalance of certain needed ingredients. In the wild they consume small insects and bugs that have plant material in their digestive tracks as well as other things, which balance them out. If you want to improve the growth rate and reproductive capabilities of your guppies, this study study suggests supplementing vitamin E.

Tank Region : Middle to top

Gender : Easy to determine. The male will have the larger, more colorful tails.

Fish Lore Forum : Guppy Forum

Photo Credit : Photos copyright JJPhoto.dk

References :
Fishbase
Wikipedia