The potential impacts of low and high salinities on salinity tolerance and condition index of the adult pearl oyster Pinctada imbricata radiata (Leach, 1814)

Abstract

Background: Salinity is one of the most consequential environmental stressors affecting marine organisms. Knowledge of salinity tolerance is of particular value to aquaculture. However, little is known explicitly about the salinity tolerance of oyster adult stage. The present study was designed to elucidate the salinity tolerance range of Pinctada imbricata radiata in order to determine the appropriate locations for grow out phase of pearl oyster culture and to assess the possibility of applying new "low salinity post-operative care" method that greatly enhance the pearl quality after implantation. The effects of extremely low and high salinities were quantified on the adult oyster survival and the ecophysiological state. Oysters were experimented in acclimated and non-acclimated sets in salinities ranged from 10 to 55 ppt (part per thousand). Results: It was found that the pearl oyster has a wide tolerance range of salinity. Within the optimal salinity range (25-38 ppt), no mortality was recorded. The mortality was significantly decreased and ceased in acclimated group as compared to non-acclimated in different ranges of salinities. Condition index (CI) of oysters reared in different salinities after acclimation and without acclimation showed considerable variations in particular, at low salinities. Conclusions: It is concluded that P. imbricata radiata can be reared in salinities up to 50 ppt during the growth phase. Low salinity post-operative care method can be applied on P. imbricata radiata after implantation by immersion in low salinities ranged between 20 and 25 ppt.

The Effects of Temperature and Salinity Stressors on the Survival, Condition and Valve Closure of the Manila Clam, Venerupis philippinarum in a Holding Facility

“…The condition index (CI) is an ecological and physiological indicator that is widely used to assess bivalve fitness and the effects of environmental stresses [21,36]. After each experiment, separated weights for tissues and shells were obtained after dissecting and drying in an oven (VS-1202D3-S, Vision, Bucheon, Korea) at 65 • C for 48 h and then weighted using an electronic microbalance (PX224KR/E, Ohaus, NJ, USA).…”

“…The reported effects of an increase in temperature include changes in growth [10,11], behavior [12,13], metabolism [14,15], and mortality [12,16]. Salinity effects include abnormal endogenous rhythms [17], changes in behavior [18][19][20], decreased condition index [21,22], and increased mortality [23]. Short-term temperature and salinity stressors, such as heatwaves and heavy rainfall, can threaten growth, recruitment, and survival at the population level [24,25].…”

The Effects of Temperature and Salinity Stressors on the Survival, Condition, and Valve Closure of the Manila Clam, Venerupis philippinarum in a Holding Facility

“…The condition index (CI) is an ecological and physiological indicator that is widely used to assess bivalve fitness and the effects of environmental stresses [21,36]. After each experiment, the clams were dissected and divided into tissues and shells.…”

“…The reported effects of an increase in temperature include changes in growth [10,11], behavior [12,13], metabolism [14,15], and mortality [12,16]. Salinity effects include abnormal endogenous rhythms [17], changes in behavior [18][19][20], decreased condition index [21,22], and increased in mortality [23]. Short-term temperature and salinity stressors such as heat waves and heavy rainfall can threaten growth, recruitment, and survival at the population level [24,25].…”

Polyculture of Juvenile Dog Conch Laevistrombus canarium Reveals High Potentiality in Integrated Multitrophic Aquaculture (IMTA)

“…In tropical to subtropical regions, the temperature and salinity of land-based saltwater aquaculture are usually 15–30 °C and 15–35‰, respectively. Substantial salinity fluctuations due to heavy rains are common in saltwater ponds [ 25 , 26 ]. Salinity often plays a major role in determining the distribution of many marine organisms, primarily because of its effects on many physiological and behavioral processes [ 27 ].…”