Zebrafish are a type of tropical fish native to the freshwater streams of India and Myanmar. They tend to be very small fish, with most not growing to be longer than 1.5 inches long (3.8 cm). Some types have black and white zebra-like stripes running horizontally across their bodies, while other species may be pink or blue in color with noticeable spots. There are also differences in fin size between various species, but the type most commonly seen in the wild has short fins. Many people like to use these fish in their home aquariums because of their small size and bright appearance.
It is usually possible to tell the difference between a male and female zebrafish by looking at the fish's underside. Males typically have gold coloring on their bellies, and females normally do not. The males male also be longer and slimmer. Female zebrafish lay eggs on a daily basis, so they will normally appear to be rounder than the males. Another way to tell the difference between the sexes of zebrafish is to watch the males chase the females at breeding time, which happens early in the morning almost every day.
Zebrafish are somewhat unique because of the development of their embryos. The embryo develops on the outside of the mother fish, and it is also transparent. This makes the zebrafish very interesting to scientists because they can actually study the young as it develops in real time. Scientists are trying to use this to their advantage because baby zebrafish develop in much the same way as baby humans. This means that a scientist can manipulate the cells as the fish develops to see what effect this manipulation has on development, which may ultimately help scientists determine what causes certain birth defects in humans.
In most cases, zebrafish are a good choice for someone who is just getting started with keeping aquarium fish. They tend to be very easy to take care of and are relatively inexpensive. These fish may also be fun to watch because they have a playful nature. Keeping clean water in the fish tank at all times is important to their survival, but the water doesn't have to be fresh. They do well in older water as long as it is kept clean of old food debris and dead eggs, but it may need to be changed if it starts to look hazy.