Osmotic and ionic changes in Taiwan abalone Haliotis diversicolor supertexta at different salinity levels

Abstract

Osmotic and ionic changes in Taiwan abalone Haliotis diversicolor supertexta (5.4±0.28 cm) were investigated after they were transferred individually from 33 practical salinity unit (psu) to 23, 28, 33 and 38 psu after 0.25, 0.5, 1, 2, 3, 6 and 9 days. Hemolymph osmolality of abalone stabilized within 2 days after they were transferred to different salinities from 33 psu. Hemolymph osmolality, Cl −, Na + and K + concentrations increased directly with medium salinity. Hemolymph osmolality was 652, 789, 945 and 1103 mOsm kg −1 for the abalone transferred to 23, 28, 33 and 38 psu, respectively. Hemolymph Cl − was 275, 323, 365, 409 mmol l −1, hemolymph Na + was 312, 376, 465, 569 mmol l −1 and hemolymph K + was 8.2, 10.1, 11.9, 12.8 mmol l −1 for the abalone transferred to 23, 28, 33, 38 psu, respectively. It is concluded that H. diversicolor supertexta are hypo-conformic and hypo-ionic with respect to Cl − and Na +, but hyper-ionic with respect to K + over ambient media in salinity ranges of 23–38 psu.