Effect of different levels of salinity on the viability of persian stuirgeon, Acipenser persicus, embryos during different developmental stages

Abstract

Because of limited information about the developmental stages of A. persicus eggs and larvae in brackish water, the experiment conducted to compare the effects of salinity on ontogeny of Persian sturgeon embryos during incubation period. Fertilized eggs were divided into 50 gr groups and transferred directly into brackish water treatments with 0.5, 2, 4, 6, 8, 10 and 12 ppt salinity. Mortality and abnormality percent of embryos in three different developmental stages including gastrula, s-type heart formation and before hatch stage (35th embryonic stages) were measured and compared. Results showed that the mortality and abnormality of Persian Sturgeon embryos increased a long with increase in salinity but the embryos showed more tolerance during blastula and gastrula stages in lower salinity and larvae could not hatch in salinities more than 6 ppt. Results suggest that as the salinity increases more than 6ppt the embryonic development will be retarded or make it useless in Persian sturgeon. All in all, the salinity tolerable range during incubation period in Persian sturgeon is between 0.5- 6 ppt.