Which are the most common pets? Dogs, cats... No! Fish. In France, for example, there are about 22 million pet fish, but only 7.7 million pet dogs, 8.8 million pet cats and 5.4 million pet birds. In France, the aquarium lovers are organized in 50 clubs and 6 large associations that organize congresses, competitions and diverse pet fish markets annually. They even have magazines, edited in numbers from 35,000 to 65,000. In fact, studies show that watching an aquarium has an excellent effect on improving the mood.

It is hard to say the number of pet fish lovers, as not anybody buying an aquarium and some fish turns into a fish keeper. This is one of the shortest passions, which requires knowledge of chemistry, physics, biology, ethology (the science of the animal behavior) and even mechanics, as each fish species requires specific food and vegetation, temperature values, water salinity, resting time,

The first known aquarium keepers were the Chinese: during the Tang dynasty (618-907 AD), they practiced the selective breeding of the goldfish and koi carps. Today, the goldfish is perhaps the most common aquarium fish. During the beginning of the 18th century, the goldfish reached England and, from this country, it conquered the whole Europe. 1780 was the year of definitive establishment of this fish in Europe.

The first public aquarium was inaugurated in London in 1853, under the care of Zoological Society. The aquarium keeping turned into a real discipline and the exhibition of the first marine aquariums, between 1960 and 1970, represented the great jump of this science.

To achieve the best results, the keepers must try to make a biotope-aquarium in which an ecosystem is remade by joining various species of fishes. Practice reinforced by theory will decide the success or failure of this.

Until the '90s, the only sea fish reproduced in aquariums were clown fish (Amphiprion). The next sea species to be reproduced in aquariums was the Banggai cardinal fish (Pterapogon kauderni), originated in the area of the Banggai Islands (Indonesia), a mouth breeder (one of the parents guards the eggs in its mouth).