Inclusion of algae in the diet, although enhancing growth, is not reflected in
soluble-protein content, enzyme activity, ammonia excretion, or metabolic substrate.
Apparently, algae play a role as source of vitamins or other micronutrients for
postlarvae.
In postlarvae fed on artificial diet alone, we obtained the lowest growth, low
soluble-protein content, high protease and amylase activities, higher ammonia excretion,
and lower O:N ratios. These results indicated that this diet did not satisfy the nutritional
requirements of L. setiferus postlarvae. However, when we combined the artificial diet
with Artemia nauplii and with Artemia nauplii plus algae, postlarvae grew better than
when they were fed on MCD or Artemia nauplii alone, showing that MCD contained
some nutrients that are not present in Artemia nauplii. We can then recommend partial
substitution of Artemia nauplii for MCD and the use of algae in the rearing of early L.
setiferus postlarvae, which, besides enhancing postlarvae growth, avoids Artemia
overpopulation in rearing tanks, and reduces the cost of the operation with better
assimilation of the diet.