H. grandinella H. bifurcate H. chorelligera H. cirrifera H. decemsulcata H. geleiana H. máxima H. mínima H. minuta H. oblonga H. ovata H. verrucosa H. viridis H. vorax Halteria, sometimes referred to as the jumping oligotrich, is a genus of common planktonic ciliates that are found in many freshwater environments.
[2] Species of Halteria can be identified by their unique jumping movement which is enabled by an equatorial row of stiff cirri that beat in unison, allowing the organism to move very quickly backwards.
Members of the genus Halteria are heterotrophic and serve as important bacterivores in the habitats they occupy as well as being preyed upon primarily by metazoans.
[4] The cells of Halteria are roughly dome shaped and in addition to the equatorial cirri, they possess a collar of cilia around the buccal opening used for feeding and locomotion.
The organism he observed was small, swift, and seen to stand still before quickly changing direction and travelling straight, which is consistent with the characteristic movement of Halteria.
[7] Descriptions of Halteria at this time were still rather vague, focusing on the quick jumping movement that results from the beating of its cirri and the presence of oral cilia.
This means that the oral cilia form an incomplete circle around the buccal cavity, and do not surround it completely as was previously assumed.
[2] A collar of prominent oral cilia can be found at the anterior end of Halteria cells, partially surrounding the buccal cavity.
[2] Just beneath the membranes of the cortex, the body shape of Halteria is stabilized by microtubules in a basket configuration.
Also during this next stage of encystment, the conical structures formed in the cytoplasm attach to the outer layer of the developing cyst, called the ectocyst.
The species Halteria grandinella is considered cosmopolitan, meaning that it is found in habitats across the world.
[13] Other species are less common and so they are less well defined, however frequent descriptions of Halteria grandinella have provided insight into the genus as a whole.
Halteria do frequently eat green algae which, when observed in food vacuoles, has led to misclassifications in the past when mistaken for endosymbionts.
[16] It has been proposed that the characteristic jumping behavior of Halteria was evolved as an escape strategy to avoid such predation.
[16][15] Halteria spend most of the time either stationary or moving smoothly through water propelled by the cilia at their anterior end.
[16] Jumping behavior in Halteria requires 41% of the organism’s total metabolic rate,[16] and so employing it too frequently would be an inefficient use of energy.
Various changes in morphology then occur through maturation divisions including a decrease in the number of cirri in both cells and the loss of buccal membranelles in one of the pair and the entire oral apparatus disappears in the other.