Colour polylithism of the domestic cat

Berezina E.S.

Popova Y.A.

Branch of Omsk pedagogical university in Tara

Nowadays the domestic cat (Felis catus) has been studied in anatomical, physiological, epizootological, epidemiological aspects. Breeds of cats have been described quite well, but besides pure-bred cats there are out-bred and cross-bred ones, that are not the subject of investigation of the modern scientists. Studying of polylithism and colour domination of cats in the southern part of the Western Siberia (in the north of Omsk region and in the south of Tyumen region) is interesting from ecological and, perhaps, epizootological points of view. Colour distribution of out-bred domestic cats hasn’t been studied before in Omsk region.

Cat family (Felidae) includes 2 subfamilies, 4 genera and 35 species. [6,7,9]. There are 9 species in the Russian fauna. Cat family is represented by 6 species in Siberia, there is one species in Omsk region – Lynx. Different sources say that breeds of cats vary from 100 to 500 [3, 9, 12]. Estimated population of dogs in Russia varies from 14 to 23 million of individuals and can reach 50 million, and cats from 7 to 40 million [2,4].

While studying morphological features of cats we took into consideration the texture of hair, its length, colour. According to the length of the hair cats are divided into long-haired, half-long-haired and short-haired breeds [3. 12]. Selectionists divide cats into long-haired and short-haired, with curly hair, harsh-haired and hairless ones [9, 10, 11].

While depicting colours of the cats’ coats scientists take into account colour of the iris (for studying of genetic peculiarities, showing up of recessiveness, homozygosity. An iris contains pigmental cells which define colour of cat’s eyes. The main colours of the iris are: green (basic), yellow (basic), orange, blue, lavender [8].

The colour of cats’ coats is quite diverse and there is no concrete classification of it. In scientific literature you can find 5 classifications of the colour of cats’ coats:

1. solid, spotted, patterned [1].

2. black, white, blue-grey, three-coloured, striped, part-coloured [12].

3. spotted (speckled), striped (tiger), marble-striped (tabby), zonal (ticking) [3].

4. smooth-coloured, (self), two-coloured, with tabs, multi-coloured, tabby, combined, Siamese (with markings), Siamese (combined) [9].

5. self, tabby, silvery (smoke group), colour-point (Himalayan), tortoise shell and blue-creamed (blue tortoise shell), party-colour [5].

This research work was aimed at studying the population of domestic cats in Tara town (Omsk region). The cats, living in households and apartments, were observed (inspections of households (n=86) and apartments (n=10). There were used phone polling and questionnaire design of Tara residents to get information about domestic cats (n=87 persons) ( number of cats, coats’ colour, eye colour, hair’s length, sex, breed, age) and about dogs (number). 286 cats are accounted, 251 of them are described.

As a result of the research it was founded out that 702 residents of the investigated territory had 286 cats and 179 dogs. Out of 286 cats males were 151, females 133. Out of 702 interrogated people 99 children had contacts with cats, 6 pregnant women had contacts both with dogs and cats. The ratio “man : cat” was 1:0,41, “cat :dog” -1:0,63, “male :female” -1 : 0,88. Consequently more domestic cats than dogs lived on the investigated territory. Males predominated over females that indicated that population was quite stable. The estimated population of cats in Tara was 12300 species, dogs – 7749. Domestic cats predominated but there were also stray cats. An average cats’ age was 3,2 years old (max=16 years old). The mass of adult cats varied from 2 to 8 kilos. An average body mass of studied domestic cats in Tara was 2,9 kilos.

The research in Tara showed that out-bred cats dominated in cats’ population (n=199, 79,3 %), cross-bred ones occupied the middle position (cross- breed with Siamese cats (n=25) – 10 %, cross –breed with Persian cats –(n=4) -1,6 %). The proportion of cross-bred cats was 11, 6%, pure-bred cats – 9, 1 % (Siamese (n=10) – 3,9 %, Persian (n=13) – 5,2 %).

Colours of domestic cats’ coats in Tara are quite various. They are: skewbald (n=78, 31,1%), wild (n=47, 18,7%), grey (n=27, 10,8%), Siamese (n=26, 10,3%), white (n=18, 7,2%), smoke (n=9, 3,6%), chocolate (n=3, 1,2%), pink (n=1, 0,4%), black (n=20, 8%), red (n=22, 8,7%).

It was found out that the majority of domestic cats in Tara were short-haired ones (n=165, long-haired – (n=71, 28%), half-long haired – (n=15, 6%).

According to the colour of the iris Tara cats were divided in the following way: with green eyes ( n=136, 54,1%), pale blue eyes (n=50, 20%), yellow eyes (n=32, 12,7%), grey eyes (n=15, 6%), brown eyes (n=14, 5,6%), blue (n=4, 1,6%).

Thus the dominating species of cats is – skewbald colour of coats (various variants), short hair and green eyes of various tints. Then goes wild colour, that is the evidence of probability of survival of the most widespread colours on the one hand and domination of these colour genes on the other hand. Heterozygosity predominates in the cats’ population.