Here’s a beautiful “studio” shoot of our laboratory’s cover girl, Rotiferella, taken by Stefan using a stereomicroscope. This is a mictic female of Brachionus calyciflorus carrying five male eggs.
Here’s a beautiful “studio” shoot of our laboratory’s cover girl, Rotiferella, taken by Stefan using a stereomicroscope. This is a mictic female of Brachionus calyciflorus carrying five male eggs.
how do you know that this are male eggs?
You can see it by the size: female eggs are larger than male eggs. The rotifer we are studying, reproduces most of the time parthenogenetic (= asexual, so no fertilization needed). Under certain conditions, however, sexuality enters the life history of this animal, and the females start reproducing male offspring. Those males are only needed to fertilize females, and so they lack any structure associated with food intake and digestion. They do not grow after hatching, and have a life span of about one-quarter of that of females. Some biologists describe the males as ‘free-swimming packets of sperm’, as that is their sole function. 🙂