The average size of 8 h old larvae were 3.21±0.04
mm (n= 10) in length. The mouth was not yet fully
developed but only a conspicuous depression
recognized the position of mouth. A small slit at the
posterior end of the yolk sac was an indicator of anal
pore. Internal body organs, like as the heart and
brain were seen to become more distinct and
movement of body fluid was conspicuous. Ray like
markings was dimly noticeable at the last part of
caudal region. At this step, the majorities of the
larvae became active and move to the water surface
that allowed for aerial oxygen uptake