Study of different levels of Lactobacillus spp and Bacillus spp probiotics in larval-culture tanks on larvae quality indices of Litopenaeus vannamei

Abstract

Introduction: The past studies have shown that the use of some probiotics has improved
growth, reproductive and immune systems in crustaceans. Litopenaeus vannamei is the
most important culture species of crustaceans in the country and this shrimp grows better
than other shrimps.
Materials & Methods: In this study, the effect of both probiotics based on quality
indicators includes: larval stage index (LSI), larval condition index (LCI), larval dry weight,
larval survival, Simultaneity of larval maturation to post larvae, time of emergence of first
post larvae, duration of larval period and salinity and formalin stress tests in order to
investigate Improvements in qualitative growth indices and immune system of Vanami
shrimp larvae were examined. For this purpose, three concentrations of Bacillus probiotic
with dose 6×105, 3×105 and 1×105 and three concentrations of Lactobacillus probiotic with
dose 6×106, 3×106 and 1×106 were added to the water tank of Vanami shrimp larvae.
Results: The results showed that the larval quality indices at level 3 of both Bacillus and
Lactobacillus probiotics were the best response and respectively, respectively 67±3.2 and
62±7.28, dry weight 139±3.99 and 138±22.23, larval stage index 11.55±0.26 and
11.46±0.11, larval condition index 1.86±0.06 and 1.88±0.13, Simultaneity of larval
maturation to post larvae 1.45±0.23 and 1.41±0.04, time of emergence of first post larvae
7.5±1.1 and 7.7±1.52, duration of larval period 8.91±0.73 and 9.11±0.6 and salinity and
formalin stress tests also show significant differences for all indicators except dry weight
index and time of emergence of the first larval post for Bacillus probiotic.
Conclusion: Finally, it can be concluded that the use of both probiotics increases growth,
faster development, and longer survival and increases the resistance of the immune system.