receptors (GHS-Rs) are endogenous receptors for growth hormone secretion (ghrelin) that belong to the G-protein-coupled receptor family. GHS-Rs play a role in regulating animal growth and energy homeostasis. GHS-R is a candidate quantitative trait loci related to obesity and growth in mammals. We used RT-PCR and PCR to isolate two. The open reading frames of encode 360 amino acids that share 96% identity. In addition, there are transcription variants, an alternatively spliced 191 bp fragment from 490 nt to 680 nt in ORF with GT-AG at both ends. These transcripts led to a premature termination of translation, encoding 184 aa, and only contained three and a half transmembrane regions, which differs from the reported intron retaining variants among tilapia. The ORF of was separated by one intron, locating between the first and second base of A260 coden. The introns of were 676 bp and 885 bp in length, respectively. We found 32 SNPs on two population using alignment sequences from different individuals. We then genotyped 9 SNPs using PCR-RFLP. We encountered each genotype in 322 individuals, but there was an obvious bias in the distribution. The sites were significantly associated with juvenile and adult fish weight gain (<0.05, respectively). Individuals with CC and GG genotypes grew faster than other individuals. In addition, a further five sites were correlated with weight gain at certain stages or sex. To determine the applicability of the markers obtained in this experiment, we tested 610 individuals from seven additional families using four markers. The sites remained significantly correlated with weight gain. Therefore, these two sites can be used as references for the molecular breeding of .