Abstract:
Studies on the biological characteristics of rotifers and the effects of various salinities, foods
and starting densities on the growth of rotifer populations were performed in 1998 – 1999.
The results showed that:
+ The mean size of cultured rotifers (Brachionus rotundiformis – Type S) in Khanhhoa was
173.33 21.45 m (S – Type). In the temperatures of 27 - 280C, the age at maturity was
18.13 1.76 hours; the interval between two spawning times was 3.93 0.53 hours; the total
number of egg in one egg laying was 1-3 eggs; the total number of egg produced during one
life cycle was 18.1 2.04 eggs; the length of the life cycle was 4.47 0.71 days.
+ The rotifer population developed best in salinities of 15 - 20ppt.
+ In the range of start densities from 5 to 30 inds/ml, higher start densities yielded, higher
maximum densities.
+ The best food for rotifers was micro-algae, followed by yeast, mixture of micro-algae and
yeast also gave the good result so this could be used to reduce the cost of rotifer production.
