Effect of Different Water Salinities on the Larvae of the Blue Bream Ballerus ballerus (Linnaeus, 1758) during Rearing

SIMPLE SUMMARY: Climate change and negative anthropogenic pressures are becoming huge challenges for quite a number of populations of both terrestrial and aquatic animals. To a significant degree, fish—the most numerous representatives of vertebrates in the world—are exposed to changing temperature conditions but also to the physical and chemical conditions of inland waters. Any biotic or abiotic factor, to a greater or lesser extent, affects the adaptability of individual fish species to the prevailing conditions in the waters in a given area. ABSTRACT: The influence of water salinities of 3, 5, and 7 ppt on the growth and survival of Ballerus ballerus (L.) larvae was studied. The control group was fish reared in freshwater (0 ppt). The larvae showed high tolerance to water salinities of 5–7 ppt. The mean final weight of the larvae ranged from 48.6 to 64.1 mg, with corresponding mean total lengths from 18.9 to 22.6 mm, depending on the water salinity level. The best larval length increments were recorded in water with salinity of 3 ppt. They were only slightly lower in 0 ppt water, and there were no statistically significant differences between the breeding rates calculated for larvae reared in 3 ppt water. Depending on the salinity level of the water, the final survival rate of the blue bream larvae ranged from 83.5 to 98.6%. The blue bream larvae reared in water with salinity levels of 5 and 7 ppt were statistically smaller than the others, but the results obtained were equally satisfactory.