Brachionus calyciflorus

Brachionus calyciflorus is a planktonic rotifer species occurring in freshwater and light brackish water. It is often used a living food for larve stages of fishes. Brachionus is slowly moving, and are highly digestible. They rapidly reproduce, and feed on cheap algae. They live long enough in sea water to be used a living food.

distribution of Brachionus calyciflorus

From all the rotifers this is the most abundant rotifer and it can be found on every continent in every fresh water lake, a cosmopolitan herbivorous rotifer.

collecting Brachionus calyciflorus

To collect Brachionus calyciflorus you need two nets: one for the catch of this rotifer: with a fine, soft, sheer fabric of plain weave. The other a more coarse screen to filter out the majority of other water organism. Sometimes other rotifers are collected too.
But the have a much lower reduplication rate and will disappear after a short time.
B. calyforus can also be hatched from dormant eggs, that can bought on the internet.

reproduction the Brachionus calyciflorus

One rotifer can easely become a million in some days. This is done by asexual reproduction: A female produces 7 eggs simultaneously, no male needed. After 12 hours, these are mature rotifers that start producing eggs, a week long.

B. calyciflorus is a very variable species and also a species complex: Validation of the numerous proposed subspecies and infrasubspecific variants awaits a thorough revision of the taxon.

sexual and a sexual reproduction of B.calyciflorus

B. calyciflorus is not locked into a particular style of reproduction, but can shift its strategy conditionally upon changes in the environment. If food is abundant, there is only asexual reproduction: The females only produces eggs that give raise to females. The process of females that produce only females is called amictic. But if there are periods with high and low abundancy of food, some females can produce offspring which can have sex (males).

feeding B.calyciflorus

The feeding is done with freswater algae: Scenedesmus obliquus and Chlorella vulgaris. B.calyciflorus change their swimming and feeding behavior in response to food type in the environment. They also feed on other freshwater protozoa and on baker's yeast, Saccharomyces cerevisiae. Bakers yeast is cheap to produce, but not well suited to feed youre brachionus.

resting eggs or cysts of Brachionus calyciflorus.

resting eggs

The resting egg of Brachionus calyciflorus is an encysted embryo consisting of two concentrically arranged, syncytial tissue layers which are surrounded by a multilamellar shell. These dormant eggs can remain resting for more then ten years and are produced under unfavourable feeding conditions.

Rotifers and other protozoa in a ditch.

1 Brachionus calyciflorus, a free swimming rotifer
2 Chlorella vulgaris, an freshwater algae
3 Heliozoa or sun-animalcules, protozoa
4 Vorticella , a stalked protozoa
5 Carchesium sp.
6 volvox sp., a freshwater algae
7 amoeba proteus
8 Melicerta, a sessile rotifer