In this study, selective breeding was done between parents of different male colouration and control female (blond colour). The offspring (F1 generation) that are produced may have new colour variation from the parent in selective breeding.
The result showed that all group experiment from Group 1, Group 2 and Group 3 have produced a new variety colour of F1 generation of guppy from half red, red mosaic, HB yellow, Micariff yellow, black mosaic and metallic blue. For Group 4, the F1 guppy does not produce a new variety colour because it is a control treatment. The reason why it carried out because we need to control the colour presence from the F1 guppy to express their colour outcome, were similar to the parent selective breeding.
Colours and patterns ultimately depend on genetics. According to Mendel’s principle, colour is a qualitative morphological trait that is inherited from offspring through a parent trait. However, sex-linked colour pattern genes that interact with autosomal background pigmentation genes give rise to additional colour phenotypes (Khoo et al., 2007). Result stated from Figures 13, 15 and 17 have shown that F1 generation of guppy have expressed the colour more contrast and colourful compared with their parent selective breeding.
The F1 progeny from Group 1 (Figure 13) produced two colour varieties which is half red and red mosaic. However, the F1 red mosaic also exhibited the variegated pattern on their caudal fin while the F1 half red exhibited half of their body base with red colour including their caudal fin. Khoo et al. (1999) stated that variegated pattern is a typical dominant inheritance in guppies colour selection.
Figure 15 shown that F1 progeny from Group 2 exhibited two colours which is Micariff yellow and HB yellow. Instead of that, the colour represent from F1 Micariff yellow are quite similar with parent ? but with more contrast and brighter colour phenotype. The term of Micariff sometimes known as the “Yellow Tang” guppy, a name given them by Frank Orteca in 1995 (Shaddock, 2012). However, the F1 HB yellow also exhibited a black colour on caudal peduncle and yellow colour on caudal fin. The reason is that Y-chromosome from ? does not carry out the black gene but the yellow gene (Shaddock, 2012).
Meanwhile, figure 17 shown that F1 progeny from Group 3 exhibited two colours which is black mosaic and metallic blue. However, the colour express from F1 black mosaic are normally pale black colour from the whole body until caudal fin but presented with a variegated pattern in small area spot at caudal fin surface area. Otherwise, the colour present in the F1 metallic blue with the presence of pale bluish colour at whole body part includes caudal fin but quite shining with metallic colour on body part including the head.
In addition, varieties colour of fancy guppy has been developed by skilful breeder and hobbyist through intensive and continual selective breeding. However, Foo et al. (1995) stated that numerous varieties of guppy are bred and derived from a few founding parents as well as having undergone many generations of stringent selective breeding for desirable ornamental traits. For example, the variable colour of offspring appears thru combination colour in selective breeding parent have given a result that stated in Figure 13, 15 and 17.
During conducting this experiment, the problem that I faced is the growth rate of F1 guppy are unequal batch because the female broodstock tends to give birth in different timing event. Shahjahan et al. (2013) stated his previous study showed that the gestation period of guppy was 25-35 days. However, the female guppy may release around 15 to 25 offspring for the first-period birth. This is why the offspring F1 cannot grow very well in their batch because the competition for food and space in the tank make the other offspring growth stunted.