Brood stock is one of the most critical production components directly related to the seed quality, therefore, it is essential to work towards improving brood stock quality of different cultured species and ensuring their availability. Using gamete cryopreservation is one way of improving the brood stock for quality seed production. Spermatozoa of genetically improved fish stored for several years in liquid nitrogen (-196C) have been successfully used for fertilizing the fresh eggs and thereby improving he gamete quality. Such technique can be popularized among the hatchery owners to overcome the inbreeding problem and to establish genetically viable brood fish population. Further, problems of seed shortage can substantially be reduced if fish can be bred round the year. Although multiple breeding and success in offseason breeding through controlled gonadal maturation in carps have been able to extend the breeding period, further efforts are necessary to bridge the gap and extend such breeding program in other species.
Genetic Improvement and Genomics
Genetic up gradation and breed improvement are key areas for sustainable aquaculture. Prioritization of species, development of a broad genetic base of the selected species and subsequently development of improved strains through selective breeding are being given top priority. Controlled breeding and using same population over the year’s results in poor genetic base leading to retarded growth due to inbreeding depression. Selective breeding for increasing number of cultivable fish and prawn should be taken up in similar fashion as that of ‘Jayanti rohu’ which has showed more than 17% higher growth per generation. Selective breeding of freshwater prawn also showed good response. Effective dissemination of the improved stock has the potential to contribute significantly to the aquaculture production. The role of the fast growing disease resistant and feed efficient stocking material will bring efficiency to the sector.
Genomics resources are complementary to the conventional genetic improvement programs maps, experimental populations, EST databases, BAC libraries, cDNA microarray, SNP genotyping platform have been generated for several freshwater finfish in fish can lead to marker assisted selection (MAS) and genome wide marker effects for a performance trait can lead to genomic selection( GS). With the advent of next generation sequencing technologies, it is anticipated that genomics resources will continue to expand in the coming decades.
Source: Source: Aqua Aquaria India