Table 1 Timetable of developmental stages of Schizocardium karanakawa at 19 °C and 23 °C
Developmental stage | February 25 at 19 °C | April 10 at 23 °C |
|---|---|---|
1st polar body stage embryos are slightly negatively buoyant | 50 min | |
2nd polar body | 1 h 10 min | |
2-cell | 2 h | 1 h 30 min |
4-cell | 2 h 45 min | |
8-cell | 3 h 20 min | 2 h |
16-cell | 3 h 55 min | 2 h 25 min |
32-cell stage embryos are neutral to positively buoyant | ||
Early blastula | 8 h | 4 h 15 min |
Late blastula | 10 h | 5 h 20 min |
Mid-gastrula (hatching) | 17 h | |
Late gastrula (ballooning) | 20 h | |
Proboscis pore-stage (Fig. 3I) | 22 h 30 min | 9 h |