Effects of calcium availability on growth of larval Lake Sturgeon

Abstract

A variety of environmental factors are known to influence growth rate and survival of larval fish. The effects of water chemistry, such as calcium hardness of freshwater systems, have been reasonably well-described in teleosts in the early life stages. However, the Lake Sturgeon, Acipenser fulvescens, is unusual in the conjunction of high calcium demand for growth in early life (as in all vertebrate animals), but low internal calcium reserves due to relatively few bony structures, especially in early life. This study reared Lake Sturgeon from hatch until after first feeding in 0.1, 0.2 and 1.5 mM [Ca2+]. No differences were observed between rearing environments in hatching success or survival. Fish reared in the lowest [Ca2+] demonstrated earlier significant increases in wet weight and total length, and absorbed yolk at a faster rate. Fish in all treatments accumulated Na+ and Cl− throughout the pre-feeding stages and continued to increase whole-body [NaCl] in the calcium-limited water after feeding. Continued growth of fish in the lowest calcium concentration was significantly impacted as the fish grew, suggesting that water chemistry was an important influence on developmental progression, and therefore, factors relevant to long-term survival such as condition and available time for feeding onset to occur.