ESTIMATION OF GENETIC PARAMETERS OF ORNAMENTATION TRAITS IN WILD STRAIN OF GUPPY Poecilia reticulata (PETERS, 1859)

Guppy (Poecilia reticulata) is an economically valuable species ranking among the top 10 most popular ornamental fishes. Guppies are widely used as a model organism in genetic studies due to short generation interval, ease of breeding and establishment of populations in laboratory, and the availability of many strains. Genetic improvement in the ornamentation traits like colour & colour patterns, size etc and development of new strains can be achieved through genetic selection for heritable traits and help sustain and enhance the ornamental fisheries. The present study was aimed to estimate the genetic parameters of ornamentation traits as well as the genetic gain obtained for orange spots.

A base population was established by breeding 50 full-sib families from a wild strain of guppy collected from Mumbai, Maharashtra, India and the F1 generation was produced following a nested mating design using the selected fishes of base generation. The fishes were selected based on number of orange spots and total area of the orange coloration. Body size traits and number of orange spots & their area and intensity were recorded for 258 and 213 individuals in the base and F1 generation respectively at 90 days of age.     

The average length of guppies were 21.04 ± 0.24 mm. Between family variations was observed for body size traits and number of orange spots indicating the presence of genetic variation in these traits. In the present study the number of orange spots ranged from one to five. Low to moderate heritability estimates were shown by the ornamentation traits (Table 1). The estimated genetic gain for number of orange spots was 0.08 which was about 3.96 percent and the realized genetic gain was about 20 percent. The study indicates that the number of orange spots in guppy can be improved by adopting appropriate genetic selection methods.