Goldfish Drawing Step by Step

Goldfish Drawings will be described in this article! At present, the generally accepted version of the origin of numerous breeds of goldfish is the domestication of its ancestral form in China around the 7th century AD. According to this theory, the initial material for selection were individuals of the Chinese subspecies of silver carp (Carassius auratus auratus), living in southern China. However, the “authorship” of the creation of the Chinese goldfish may be subject to doubt in connection with the findings of possible wild ancestors of domesticated goldfish … in the reservoirs of South-Eastern Europe.

If you think goldfish are born gold, you’re wrong. Baby goldfish to the age of 1-2 months look quite modest: it is a common silver-grey fish. Then the back darkens, spots appear, and the colour changes more and more towards gold and red. In domesticated breeds of goldfish, such “moult” occurs early enough, even before sexual maturity. This is beneficial to breeders: you can quickly select the best colour variants. The sex of domesticated goldfish is genetically determined: some eggs come out of males, and from others – females. Also, there are no known cases of sex change – during life, males remain males and females – remain females.

At the beginning of the 21st century, the famous USA ichthyologist Mike Tompson had a wild form of goldfish in North California, which he later named the commercial goldfish. Gynogenesis is a form of reproduction in which the egg develops without fertilization, and the sperm serves only as a stimulus to the beginning of its development. The mere fact that TZR – gynogenetic form suggests its natural origin. After all, among the numerous breeds of goldfish, gynogenetic forms are not known.

Crosses of domesticated goldfish with silver carp repeatedly took place when the former got into natural reservoirs, but there were no cases of parthenogenesis in such hybrids. Subsequently, it was found out that a part of TZR in the process of individual development can “turn” into males. Males demonstrated normal “male” behaviour, chasing females during spawning. At the same time, they turned out to be practically sterile.

The transformation of females into males in fish is not extraordinary – the experiment is carried out by adding the appropriate sex hormones in the water, such as testosterone. However, the males are obtained to be fully fertile, with normal spermatogenesis. TZRs “moult” at the age of 3 – 4 years, and very unevenly, some earlier, others later. Some of them can retain their initial silver-grey colour for several years, but they become sexually mature at the age of one year.

It can be assumed that TZR’s colour change is an adaptation that allows more efficient use of the limited food resources of shallow and often drying steppe water bodies where TZR can live. Larger fish that changed their colour to red were eaten by predators, as a result of which relatively small but already sexually mature and numerous silver-grey fish received an advantage in the continuation of reproduction.

We observe a similar adaptation in many plants: fruits at seed ripening gradually become brightly coloured, as if inviting various animals: “Eat me!” Such adaptation in TZRs is not beneficial for a single individual, but it allows for a more successful existence of the population as a whole. It could arise as a mutation in one or more individuals in a small, closed population. In case clonal reproduction arose earlier than the ability to change colour, the lack of intra-population crossbreeding could have supported the spread of this mutation.