Feeding Acipenser persicus and Huso huso (Acipenseriformes) larvae with Artemia urmiana nauplii enriched with HUFA and vitamin C: II. Effect on tolerance to shock exposure of environmental factors

Abstract

The effects of feeding Acipenser persicus and Huso huso larvae with Artemia nauplii enriched with ascorbyl palmitate (AP) and lipid emulsions on inducing tolerance against abrupt changes in environmental conditions (such as elevated levels of salinity, temperature, nitrite and total ammonia) were investigated. The 10 days post-hatch fish larvae were fed with decapsulated cysts (DC) or newly hatched Artemia urmiana nauplii enriched with saturated lipids and HUFA emulsions containing 0, 10, and 20% AP. The control groups received non-enriched nauplii as source of food. Each feeding experiment was carried out for 15 days in four replicates under controlled laboratory culture conditions. Ten randomly collected A. persicus and H. huso larvae from each replicate were subjected to different salinities, nitrite, total ammonia concentrations and temperatures. The results showed that feeding with Artemia nauplii enriched with HUFA and higher concentrations of vitamin C induces significantly higher tolerance to shocks in abiotic conditions in fish larvae of both species, as shown by higher survival. Nevertheless the two fish species did not exhibit a similar pattern of response: A. persicus showed higher tolerance compared to H. huso. Enrichment with HUFA alone did not result in a significantly improved tolerance, indicating the importance of dietary vitamin C to cope with abrupt physico-chemical changes.