Table 2. Summary of relevant publications investigating the effect of salinity on abalone physiology

Species Stressor levels Duration Parameters General findings References
Many-colored abalone(Haliotis diversicolor) 20, 25, 30 (control) and 35‰ and injection with 1.6×105 Vibrio parahaemolyticus 120 h Mortality rate, THC, phenoloxidase activity, respiratory burst activity, phagocytic activity, and bacterial clearance. Immunity and resistance to Vibrio parahaemolyticus decreased when salinity increased from 30‰ to 20‰, 25‰, and 35 ‰. Cheng et al., 2004a
Disk abalone(Haliotis discus discus) 25, 30, 33 (control), and 35 psu 48 h Suvival rate, THC, CAT, SOD, respiratory burst, phenoloxidase activity, lysozyme activity, HSP70 expression in gills. Low salinity stress weakens the immune system in Pacific abalones by decreasing the activity of phenoloxidase and lysozyme. Jwa et al., 2009
Disk abalone(Haliotis discus discus) 25‰ and 32‰ (control) 24 h Gene expressions of MnSOD, CAT, CuZnSOD, SeGPx, TPx, TRx-2, SOCS-2, and Mx. At low salinity, the gene expressions of MnSOD, CAT, CuZnSOD, SeGPx, TPx, TRx-2, SOCS-2, and Mx all increased. de Zoysa et al., 2009
Pacific abalone(Haliotis discus hannai) Changing the salinity at 3 different temperatureControl 35 psu for 7 daysFrom 35→30→25→20→15 psu for 7 daysFrom 35 →25→15 psu seven daysFrom 35 →15 psu 7 d Survival rate, and oxygen consumption. Salinity of 25–35 PSU is ideal for abalone production. Salinities below 20 PSU lower survival and oxygen consumption. Sudden salinity changes and high water temperatures enhance mortality. Lim et al., 2014
Pacific abalone(Haliotis discus hannai) 16, 18, 20, 22, 24, 26, 28, 30, 32 (control), 34, 36, 38, 40, 42, 44 and 46 ppt 77 d SGR (length, width, weight), survival rate, DNA methylation, and epigenetic structure. The optimal salinity was 30–36 ppt. There are no significant variations in global methylation levels. Salinity can cause epigenetic differentiation. Kong et al., 2017
Many-colored abalone(Haliotis diversicolor) 20, 25, 31 (control), 35 and 40 ppt 2 mon SGR (weight and length), density and sizes of mucous cells (digestive gut, gills, lips). Growth was highest around 25–35 ppt. Lip and gill mucous cells had the greatest density and smallest cell size at 40 ppt, while digestive gut cells were at 20 ppt. Creencia & Noro, 2018
Pacific abalone(Haliotis discus hannai) 26, 30, and 34 psu combined with 4°C, 6°C, 8°C, and 10°C 7 d Survival rate, antioxidant enzyme, THC, hemocyte mortality The Pacific abalone has the lowest tolerances for salinity and water temperature, at 30 psu and 8°C, respectively. Yang & Min, 2019
Pacific abalone(Haliotis discus hannai) and Giant abalone (Haliotis gigantea) 34 (control), 30, 26, 22, 18 and 14 psu 3 h salinity exposure and the culture for 7 days at normal salinity Hatching, survival rate, and abnormality. Hatching, abnormalities, and survival rates were not significantly different between 30 and 34 PSU for both species. The hatching and survival rates of both species were reduced by short-term low salinity stress, while abnormality rates were elevated. Phan et al., 2022
SGR, specific growth rate; THC, total hemocyte count; CAT, catalase; SOD, superoxide dismustase; HSP, heat shock protein; MnSOD, manganese superoxide dismutase; CuZnSOD, copper zinc superoxide dismutase; TPx, thioredoxin peroxidase; SeGPx, selenium-dependent glutathione peroxidase; TRx-2, thioredoxin-2 (TRx-2); SOCS-2, cytokine signaling-2; Mx, myxovirus resistance.