Figure 2.13 Time 11 hours

The naupliar form is recognisable. A single reddish pigmented spot can be seen which is the naupliar eye. Appendages are well developed.

Figure 2.14 Time 12 hours

The nauplii begin to hatch, typically around 12.5 hours after spawning. In this figure the bottom of the hatching envelop has been broken and the nauplii tears their way out using their appendages. Commercial hatcheries have reported that occasionally vigorous active nauplii can be seen within the hatching envelope but are unable to ‘hatch’ and die within the shell. The reason for this is unknown but may be due to poor quality and weak nauplii that are unable to tear open the hatching envelope.