MINIATURE TRIBBLES
A tribble is a miniature when it is less than 5 cm when fully grown. Tribbles don't necessarily stop growing when mature; an underfed tribble can grow larger when fed adequately, even though it often won't reach its full potential.
Because in showing and selling miniatures the smallest specimen are the most desirable, some breeders will deliberately underfeed their tribbles. However, an experienced tribble-keeper can easily diagnose underfeeding by the loose skin, dull hair color, and in severe cases, lethargic behavior of the tribble. When deliberate underfeeding has been discovered it will lead to expulsion of all the offender's animals from the show and a warning from the UFPTSBA. Repeat offenders can be expelled from all shows and have their breeder's licence revoked. First-time buyers are recommended to take an expert along when purchasing a miniature.
Because miniatures are relatively rare, all but the largest shows will not split classes in color or hair length. All coats and colors occur in miniature tribbles.
REGULAR TRIBBLES
This is the tribble most people keep. They are between 5 and 25 cm. Because there are so many tribbles in this category they are divided into subgroups.
A) Longhair tribbles. A tribble is called a longhair if it has fur of 2 1/2 cm or longer. The hair should stand up fluffy and not be tangled or matted. Spotted and leopard tribbles with long hair are extremely rare.
B) Roughhair tribbles. A roughhair tribble has hair of up to about 2 1/2 cm long. Most have many swirls in their coat. When groomed, the hair looks fluffy, when left alone it curls lightly in all directions. This is the natural hair coat of the tribble.
C) Shorthair tribbles. Shorthair tribbles have a short, smooth hair coat which should lay down in one direction. They are the easiest tribble to groom and keep clean. Most spotted and leopard tribbles are shorthaired.
GIANT TRIBBLES
A giant tribble is over 25 cm. All colors and coats occur in giant tribbles, but due to the rarity of giant tribbles most shows will have one class, as with the miniatures.
The giant tribbles should not be confused with the tribble colonies, which look like giant tribbles but are clusters of little tribbles.
A tribble colony is an incorrectly sterilized tribble which does not grow by itself, but instead multiplies and forms a colony with its offspring, appearing to be one giant specimen. The largest tribble colony observed till date was approximately 1m40 across, with a weight of over 230 kilograms.
A tribble colony will break down into its individual units when given a shot of neo-ethylene. The resulting individual specimen will be safe, non-breeding tribbles.
Neo-ethylene can also be used to suppress the ability to breed in a tribble that has not been genetically altered, but as it wears off in time, it is not a reliable method for house-hold use.
Breeders do not use it, as the first litter after a neo-ethylene treatment is usually small in number and the young tribbles are also less likely to be show material. It is used, however, to control tribbles in the wild.
CROSSBREEDING WITH TRIBBLES
Some breeders have tried cross-breeding tribbles with various other life forms, attempting primarily to come up with something that has the shape, size and disposition of a tribble, but breeds like the other life form.
This effort has met with some resistance, not in the least from those who fear they might end up with something the shape, size and disposition of the other life form, that breeds like a tribble!
So far, none of the attempts have been successful, since a tribble will not breed with any other life form voluntarily, and its self-fertilizing mechanism is powerful enough to override any attempt at forced cross-fertilization, leaving absolutely no room for experiments.