Heritability of body weight and resistance to ammonia in the Pacific white shrimp Litopenaeus vannamei juveniles

Abstract

A bstractAmmonia, toxic to aquaculture organisms, represents a potential problem in aquaculture systems, and the situation is exacerbated in closed and intensive shrimp farming operations, expecially for Litopenaeus vannamei . Assessing the potential for the genetic improvement of resistance to ammonia in L . vannamei requires knowledge of the genetic parameters of this trait. The heritability of resistance to ammonia was estimated using two descriptors in the present study: the survival time (ST) and the survival status at half lethal time (SS 50 ) for each individual under high ammonia challenge. The heritability of ST and SS 50 were low (0.154 4±0.044 6 and 0.147 5±0.040 0, respectively), but they were both signifi cantly diff erent from zero ( P <0.01). Moreover, these two estimates were basically the same and showed no signifi cant diff erences from each other ( P >0.05), suggesting that ST and SS 50 could be used as suitable indicators for resistance to ammonia. There were also positive phenotypic and genetic correlation between resistance to ammonia and body weight, which means that resistance to ammonia can be enhanced by the improvement of husbandry practices that increase the body weight. The results from the present study suggest that the selection for higher body weight does not have any negative consequences for resistance to ammonia. In addition to quantitative genetics, tools from molecular genetics can be applied to selective breeding programs to improve the effi ciency of selection for traits with low heritability.

Transcriptome Analysis of the Hepatopancreas in the Pacific White Shrimp (Litopenaeus vannamei) under Acute Ammonia Stress

“…In order to know how much of the trait of ammonia tolerance in L . vannamei is genetically involved based on the additive genetic effect model, we estimated the heritability of ammonia tolerance with these families [ 38 ]. Before the heritability estimation, we carried out a pre-experiment to detect the half-lethal time under our experiment condition with the ammonia doses reported by Sun et al [ 39 ], because the toxicity of ammonia is largely depend on temperature, pH, salinity, and body weight, etc.…”

“…During the acclimation, the holding water conditions were as follows: salinity at 30‰, pH at 7.9 ± 0.1, temperature at 27 ± 0.5°C, and oxygen higher than 6 mg/L. After the acclimation, one group was treated as the control (LV_C), and the other group (LC_E) was challenged with high-concentration ammonia (~ 62.23 mg/L) according to our previous study [ 38 ]. The temperature was 27 ± 0.5°C, pH was 7.9 ± 0.1, and salinity was 30‰.…”

Identification of SNP markers associated with tolerance to ammonia toxicity by selective genotyping from de novo assembled transcriptome in Litopenaeus vannamei

“…Fortunately, a total of 25,772 SNPs were found from these genes, which providing important candidate markers for association study. In addition, we have accumulated some groups with significantly different performance on ammonia tolerance [20,42]. Consequently, as an alternative approach to QTL mapping, we used a marker-trait association analysis to identified SNP markers that associated with ammonia tolerance.…”

“…Its base population was produced with seven commercial L. vannamei strains that were separately introduced from America and Singapore with an incomplete diallel cross experiment in 2011 at the Mariculture Genetic Breeding Center of the Chinese Ministry of Agriculture (Qingdao, Shandong province, China). A total of 1849 individuals (average body weight was 3.1 g) from 52 full-sib families of the population were performed ammonia stress test at Qingdao in 2013, and their survival time ranged from 65 to 218 h. The detail information for the shrimps and stress process could be found in our previous study [42]. The 60 first-dead individuals (as ammonia-sensitive group, AS 1 ) and the 60 last-dead individuals (as ammonia-tolerant group, AT 1 ) were used for identification of associated SNP markers.…”

Interactive effects of family and stocking density on survival and growth of the sea urchin Strongylocentrotus intermedius

“…However, in a long-term trial with extreme high temperature, Chang et al [2016] demonstrated that survival varied significantly among the families of S. intermedius. That genetic factors play important roles in survival has also been concluded for other aquatic animal species Li et al, 2016;Thoa et al, 2015;Thoa, Ninh, Knibb, & Nguyen, 2016). Moreover, in S. intermedius, completely different culture methods or diets caused significant family by environment interaction effects on growth traits (Wang et al, 2015;Zhang et al, 2013).…”