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Grow-out or field survival (GS) is one of the most important traits of striped catfish. Genetic parameters of GS in generation 4 of the growth selected population of this species were estimated based on the data of 8,004 tagged and stocked and 6,410 harvested fish representing 152 full-sib and half-sib families. The heritability and estimated and realized correlated responses for GS, its phenotypic or genetic correlations with harvest weight (HW) and other growth traits, and direct realized response for HW were calculated. The low and significantly different from zero heritability for GS (0.12±0.05) was estimated. The medium positive and no significant difference from zero genetic correlation between GS and HW was found, 0.41±0.24. The estimated selection responses with the proposed selection proportion of 13.0% for GS was 8.5% in trait unit. Current and accumulated correlated selection responses for GS were -7.8% and -1.6%, and 25.5% and 47.6%, respectively, by Estimated Breeding Value and Least Square Means estimation methods. In addition to these results, the high heritability and direct estimated and realized responses for HW pose a great potential for applying multi-trait selection, including both GS and HW in G4 and in the long run.

Development of molecular markers for growth trait in striped catfish (Pangasianodon hypophthalmus) is of importance to the aquaculture industry in the Mekong river delta. This study aims to analyze the genetic variation and the effects of the Insulin-like growth factor 1 (IGF1) and Insulin-like growth factor 1 receptor (IGF1R) genes on growth traits in striped catfish. We sequenced fragments of IGF1 and IFG1R genes from 10 individuals of fast-growing fish and 10 individuals of slow-growing fish to discover single nucleotide polymorphisms (SNPs). Among the discovered SNPs, one SNP (13,680 A > T in intron 2) of IGF1 gene, three SNPs (13,357 T > C, 15392 T > A in intron 1 and 83,894 A > G in intron 15) in IGF1R gene were filtered and further validated by individual genotyping in 70 fast-growing fish and 70 slow-growing fish using the multiplex SNaPshot method (single base extension method). Our analyses showed that two SNPs (IGF1:13680 A > T and IGF1R:13357 T > C) were significantly associated with the growth trait (p T and genotype TT of IGF1R:13357 T > C led to the positive cumulative effect on the growth (p