Comparison of the digestive enzyme activities in Artemia urmiana from nauplii to adult stages using different diets

Due to the importance of adult Artemia in aquaculture, information regarding the digestive
enzyme activities variation with inexpensive diets has great importance in Artemia at different
life stages. In this study, the effect of different inexpensive diets on digestive enzyme
activities, including trypsin, amylse and lipase of Artemia urmiana was investigated in
different life stages. The experiment was carried out with 5 treatments and each with 2
replicates over 15 days using 5 diets (wheat meal, common carp diet, soy meal, a mixture of
soy meal and canola meal (compound diet 1) and a mixture of soy meal and wheat meal
(compound diet 2) in a completely random design. Nauplii were introduced to their
cultivation environments after hatching and the digestive enzyme activities were measured in
days 5, 10 and 15 of the experiment. Positive and significant correlation were observed
between the crude protein content of the diets and trypsin activity (0.74), the carbohydrate
content of the diets and amylase activity (0.49), and crude fat content of the diets and lipase
activity (0.84). The activities of all enzymes were increased with the Artemia development in
this study. During the experimental period, the trypsin, activities were increased in all
treatments with the exception of wheat meal treatment, amylase activities were increased in
all treatments and lipase activities were increased in all treatments with the exception of
common carp diet and wheat meal treatments. Digestive enzyme activities were affected by
the diets and Artemia life stages. Regarding the increasing digestive enzyme activities until
adult stage in Artemia urmiana, using adult Artemia urmiana decreases pressure on resources
of Artemia cyst and nauplii in natural environments. In addition, this condition may result in
more economic returns and better quality of adult Artemia compared to its cyst and nauplii.
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