Sub‐low salinity impact on survival, growth and meat quality of the Pacific abalone ( Haliotis discus hannai ) and hybrids

Abstract

In recent years, suboptimal environmental conditions have been frequently reported to negatively impact on aquaculture organisms. Salinity is an important environmental factor, and its fluctuation will affect survival, growth and, potentially, the meat quality of the organisms with narrow salt tolerance cultured in coastal and inner bay. The aim of the study was to ascertain and report the influence of sub‐low salinity (28 and 30) on the production traits and nutrient composition of the Pacific abalone Haliotis discus hannai (DD), and two of its hybrids (DF and SD). In view of this, 360 abalones were subjected to four salinity levels (28, 30, 32 and 34) for ninety days. The data showed that the weight gain and the specific growth rates in wet weight between the groups followed the trend of DF > SD > DD. DF recorded the highest meat yield, which was significantly higher than SD and DD (p < .05). The sub‐low salinities tested did not influence moisture content, crude protein, total lipid and total carbohydrate (p > .05). Whilst lipid levels were fairly higher in SD and DF than in DD, at sub‐low salinities, the opposite was true for carbohydrate content. Total minerals (ash), however, were influenced by salinity (p < .05). Individuals reared at 28 significantly differed from those of the other three treatments, but there was no significant difference between the groups (p > .05). Further analysis showed sodium and potassium as the predominant minerals—with a higher concentration of sodium at higher salinities, though no significant difference was found between individuals treated at 30, 32 and 34. Zinc was the only mineral not affected by salinity (p > .05), and the accumulation of discrete minerals by the species significantly differed from one mineral to the other and proved to be species‐specific. Notwithstanding, SD demonstrated superior content of most essential minerals over DF and DD. The results in this paper infer that the Pacific abalone and its hybrids could maintain good meat quality and survival under a range of 28–34 of salinity, promoting the growth of cultured abalone under the sub‐low salinity of 28.

Transcriptome analysis reveals the molecular mechanisms of heterosis on thermal resistance in hybrid abalone

“…The Xishi abalone H. gigantea (SS), which is naturally distributed along the coasts of Japan, has a wide range of temperature adaptability [27]. The hybrid H. gigantea ♀ × H. discus hannai ♂ (SD) was produced on large-scale and has been approved to exhibit heterosis in growth rate, survival rate, sub-low salinity adaptability, and thermal resistance [27][28][29]. Therefore, SD is a good model for heterosis research, the molecular basis of which remains elusive.…”

The use of artificial feed in Haliotis squamata farming in submerged cage culture system at Lae-Lae island, Makassar

“…In addition, the rearing circumstance significantly affects abalone growth. One of the parameters is water salinity (Boamah et al, 2020;Kong et al, 2017).…”

Transcriptome analysis reveals fluid shear stress (FSS) and atherosclerosis pathway as a candidate molecular mechanism of short-term low salinity stress tolerance in abalone

“…In another experiment, H. discus hannai (DD; 16.0 ± 0.6 mm shell length; 11.6 ± 0.4 mm shell width; 0.6 ± 0.1 g wet weight) and hybrid H. discus hannai ♀ x H. fulgens ♂ (DF; 15.0 ± 0.2 mm shell length; 10.7 ± 0.2 mm shell width; 0.5 ± 0.1 g wet weight) were cultured at various salinities (36, 33 as control, 30, 27, 24, 21,18, and 15) for 60 days, following the experiment set-up described in our previous study [ 10 ]. Subsequently, survival rate and growth rate were estimated.…”

“…Moreover, abalone encounters a sudden drop in seawater salinity during severe summer rainstorms and typhoon events [ 5 ]. However, changes in ambient salinity could significantly affect abalone inflammatory and immune responses and are associated with several other physiological responses, such as disrupting electrolyte equilibrium, oxidative damage, and metabolism disorders [ 6 – 9 ], which eventually influence their survival and growth [ 10 , 11 ].…”

“…Luckily, abalone hybrids have shown superiority in tolerating diverse environmental stresses over their purebred counterparts and have benefited the Chinese abalone aquaculture industry [ 10 , 12 – 15 ]. However, there is a dearth of practical proof regarding the mechanisms driving their phenotypic differences to salinity tolerance.…”