Hey Matt,
Found this on one of my many journeys into internetland
Production of rotifer cysts
The need for continuous maintenance of live stock cultures of Brachionus either for laboratory investigations or aquacultural purposes requires considerable routine effort and involves the risk of bacteriae and ciliates contamination.
Commercial availability of rotifer eggs could be the solution by eliminating the need to maintain stock cultures and reduce the chances for contamination with ciliates and pathogenic bacteria. Furthermore, the rotifer cysts could also be disinfected prior to hatching out in a new culture inoculum.
Under optimal culture conditions, B. plicatilis reproduce by parthenogenesis, each female produce several eggs at a time which upon hatching reach the reproductive stage in a few days only. But in undesired conditions, they reproduce by bisexual and produce resting eggs ( cysts ) which deposit on the bottom of ponds. Rotifer cysts remain dormant and hatch after stimulation by specific external conditions.
The extent of resting egg production is determined by both internal and external factors. The most important internal factors are the age of the parental female and her genotype. The external factors include temperature, photoperiod, population density and grouping, and both qualitative and quantitative aspects of diet ( Pourriot et al., 1983 ). In nature, the most important factor affecting cysts production of rotifers is the supply of diets. In spring, rotifer cysts hatch and rotifer populations rapidly grow. When the diets are consumed out, the rotifers begin to produce cysts.
On a hatchery we produce rotifer cysts by adjusting only the diet supply. First we culture rotifers with algae and yeast at 25 C and 20 ppt under natural sunlight. When rotifers reach a density of 10,000 ind./l, the diets supply are gradually reduced to zero. 10 Days later, we harvest the cysts by draining off the culture water and the resting eggs are collected by sieving through a net. Then the cysts are purified and processed to a dry form. 1 gram of processed rotifer cysts include 2,000,000 eggs with about 80% of hatching rate at 28 C and 20 ppt in 36 hours.
The whole article is at:
http://www.athiel.com/lib5/rotifers.htm
I would also be interested to know how they process the cysts and dry them??.. Maybe an email might discover this??
Oh and while we are ordering ss strain?? ? ? ..,,, Put me down for a dozen! (when I get my proper rot system running well)
