Effect of incubation and preservation on resting egg hatching and mixis in the derived clones of the rotiferBrachionus plicatilis

✍ Scribed by Atsushi Hagiwara; Akinori Hino

• Publisher: Springer
• Year: 1989
• Tongue: English
• Weight: 471 KB
• Volume: 186-187
• Category: Article
• ISSN: 1573-5141
• DOI: 10.1007/bf00048940

✦ Synopsis

The marine rotifer Brachionus plicatilis typicus (Clone 8105A, Univ. of Tokyo) was cultured in 500 ml beakers to form resting eggs. Tetraselmis tetrathele was used as a culture food. Just after formation, resting eggs were exposed to various temperature (5-25 C) and light regimes (24L: OD and OL: 24D). When eggs were exposed to light just after formation, the eggs hatched sporadically over a month. No hatching was observed for six months when eggs were preserved under dark conditions regardless of the temperature. These eggs hatched simultaneously after being exposed to light and eggs preserved at 5 °C showed twice as high hatching rate (40%) as that of eggs preserved at 15-25 C (24%). Clones from resting eggs that were kept under different temperature and light regimes were reared individually to the third generation. Incubation at 25 C with lighting produced the highest (5.4% and 5.2%) rate of mictic females during their 2nd and 3rd generations, respectively. The lowest rates (0 and 1.5%) were found when the eggs were kept at 5 C in total darkness for six months. A lower rate of amictic female production was found in clones with higher rates of mixis.