Quantitative genetic parameters for early growth traits and body shape variability in Asian Sea Bass (Lates calcarifer Bloch, 1790)

Name: Suthajaree Yenmak

LCSH: Kasetsart University -- Dissertations. Ph.D. (Aquaculture) 2018

Classification :.LCCS: QL638.C34

LCSH: Kasetsart University. -- Department of Aquaculture -- Dissertations

LCSH: Giant perch -- Genetics

LCSH: Giant perch -- Growth

LCSH: Sea basses -- Genetics

LCSH: Sea basses -- Growth

Abstract: This thesis investigated the potential of establishing a selection program to improve growth and fillet traits in domesticated populations of Asian sea bass, Lates calcarifer. In the first experiment, I estimated genetic parameters for early growth traits and a length-weight relationship for a hatchery stock of Chon Buri origin. Sea bass fry were produced by mass spawning of 18 sires and 48 dams which initially were marked with passive integrated transponder (PIT) tags to identify families. Fin clips were collected from the breeders and 507 individuals of 90 days post hatch fry and genotyped at 8 microsatellite loci (Lca20, Lca27, Lca32, Lca98, Lca184, Lca185, Lca260 and Lca284). Parentage analyses indicated that 302 (out of 507) offspring were generated from 6 (18) sires and 18 (48) dams, resulting in 77 (349) half-sib and 32 (97) full-sib families (total candidate parents and families shown in brackets). Heritability estimates for weight (BW), length (TL) and body depth (BD) at 90 days post hatch were 0.15±0.09, 0.20±0.12 and 0.19±0.11, respectively. Correlations between pairs of growth traits were positive, with BW-TL (0.41±0.00), BW-BD (0.12±0.00) and TL-BD (0.94±0.01). The length-weight relationship (LWR) was developed from 2,656 fingerlings for prediction of body weight. The LWR equation was BW = 0.0151TL2.95, R2 = 0.995 and r = 0.987. The second experiment described the application of a morphometric approach to investigate the effects of genetics and rearing environment on body shape variation in Asian sea bass. The principal component analysis (PCA) method suggested very little morphological difference among four hatchery populations. Subsequently, discriminant function analysis (DFA) method was used to assign individuals to their stock of origin, with accuracy ranging from 65.5% to 77.7%. The analysis of a sea bass stock reared in two locations suggested that salinity affected body shape differentiation. DFA identified the two most discriminating variables, which were both correlated with head size, and assigned individuals with 100% accuracy to their group. In the third experiment, I developed prediction equations for fillet traits in 390 days post hatch sea bass. Weight and body measurement data of 100 live fish from each of four stocks (n = 400) were collected. Fillet percentage varied slightly from 47.33% to 49.88%. Prediction equations developed from body weight and standard length using simple linear regression model yielded the R2 values of 0.99 and 0.89 for fillet weight and 0.17 and 0.19 for fillet yield, respectively. The correlations between values predicted from the body weight models and actual values were 0.99 for fillet weight and 0.26 for fillet percentage.

Kasetsart University. Office of the University Library

Address: Bangkok

Email: tdckulib@ku.ac.th

Name: Supawadee Poompuang

Role: Thesis Advisor

Name: Skorn Koonawootrittriron

Role: Thesis CO-Advisor

Name: Wansuk Senanan

Role: Thesis CO-Advisor

Created: 2018

Modified: 2025-06-29

Issued: 2025-06-29

วิทยานิพนธ์/Thesis

application/pdf

URL: https://www.lib.ku.ac.th/KUthesis/2561/suthajaree-yen-all.pdf

CallNumber: QL638.C34 .S88

eng

DegreeName: Doctor of Philosophy

Level: Doctoral Degree

Descipline: Aquaculture

Grantor: Kasetsart University

©copyrights Kasetsart University

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