Rotifers are a very popular creature among the aquarium hobbyist community, however, many people don’t know much about these species…except for that their fish love to feed off them. So, we’re here to break down the most essential things to know about rotifers behaviour, diet, and lifecycle.
Rotifers or ‘Rotifera’ if you want to call them by their scientific name, make up a phylum of microscopic or near-microscopic animals. Most rotifers are around 0.1-0.5mm long however, some rotifers can reach over 2mm in length! Rotifers are an important part of the freshwater zooplankton, being a major food source to fish and other marine creatures. The body of a rotifer is divided into a head, trunk, and foot, and is typically somewhat cylindrical. There is a well-developed cuticle, which may be thick and rigid, giving the animal a box-like shape, or flexible, giving the animal a worm-like shape. The corona on the head of the rotifer is one of the most distinctive features of the creature, making it easy to tell it apart from other zooplankton species.
Behaviour & Diet
Not all rotifers are the same in terms of the way they get around. Some rotifers are free swimming and truly planktonic, while others move around by inch-worming movements on the surface of the ocean or wherever they are placed. Some rotifers are even sessile which means they live inside tubes. Similarly to other plankton species, rotifers eat organic detritus, dead bacteria, algae, and protozoans.
Due to rotifers being sexually reproductive, the female is usually larger than the male. Sometimes this size difference is relatively small, however, in some species, the female can get up to ten times larger than the male! Rotifers are usually preyed on by copepods and other fish, jellyfish, and starfish as they are one of the smallest animals of the ocean.