Epistylis

Columns bells ( Epistylis sp., Drawing a microscope view)

Columns bells ( Epistylis ) constitute a genus of unicellular ciliate. Like the other species of the family Epistylidae live the pillars bells sessile on aquatic plants and detritus, but also as Ectokommensalen on the body surface of crustaceans, fish and turtles. They attach themselves by a stalk to the surface of the animals and swirls her eyelashes food in their inverted bell-shaped cell body.

Features

The individual cells can be 10 to 250 microns in length and 10 to 80 microns wide depending on the type. Their stems are branched and form colonies. At the end of each stem is an individual ( zooid ). The colonies reach a length of several millimeters and are macroscopically visible as growth. Within the stem, no Myonem is like the bell animalcule, so that the colonies can not contract as Vorticella or Zoothamnium.

The stem is branched dichotomously, after each bifurcation is a stem shorter than the other. On shorter one separation zone is applied before each division. At these points the oldest branches can be repelled and move freely floating through the water until they find a suitable place to form a new colony.

Other features of the genus are a wide lip formation at the apical end and a continuous easier lash line to the mouth area. In related genera such as Campanella or Heteropolaria this spiral has one and a half or four to six whorls. Opercularia and Orbopercularia have no lip formation.

Way of life

In contrast to the ectoparasites Ektokommensalen are usually harmless. They live off the food waste of their host animals or Epistylis mainly of bacteria that decompose the waste.

Mass infestation

In environments where by contamination of the nutrient content in the water is very high, it can lead to a proliferation of Epistylis. This can lead to skin irritation and ulcers in the fish and make them susceptible to infection.

Fish disease

An excessive infestation of fishes by Epistylis be determined by small white, cotton-like growths the size of a grain of rice. The infection can occur on any part of the body, but he is usually first seen on the sidelines of the fish. At sites with massive infection with Epistylis pass through secretions of the unicellular often bloody wounds. Mass infestation of the gills may affect the respiration of fish.

An initial diagnosis can be made ​​with the naked eye, a more accurate statement is, however, feasible only with a microscope.

Infestation of crayfish

Even with crayfish of mass infestation by Epistylis is an indicator of polluted water and low oxygen concentration ( high BOD5 value of oxygen consumption ). The infestation may affect the quality of production in cancer breeds. Reinforced Epistylis growth takes place at higher water temperatures. Again, a macroscopically visible white or gray fuzz is on the exoskeleton of the crayfish.

Prevention and treatment

Clean, not too warm water is the best way to prevent a mass infestation. Appropriate feeding prevents too much organic material in the pond or aquarium. Lower stocking density helps to prevent infection. In the aquarium, a filter with UV light Epistylis and other pathogens kill.

Applying jodfreiem sodium chloride (NaCl) in a concentration of up to 0.6% for the duration of a maximum of 10 days or a mixture of formaldehyde and salt in the water to achieve the best effect.

System

The genus Epistylis is probably not monophyletic, that is, not all species are descended from a common ancestor. Epistylis galea example shows a polymorphism of single individuals within a colony. Occur, as well as in many types of Zoothamnium, macro and Mikrozooide on. Although already Fauré Fremiet 1907 suspected that Epistylis galea could be assigned to the genus Campanella, showed only molecular genetic studies at the Institute of Microbiology, Chinese Academy of Sciences, 2005, a greater affinity of Epistylis galea to Campanella and Opercularia species than to other Epistylis - species. The molecular genetic analysis of 18S rRNA sequences of various sessile ciliates from the subclass Peritrichia also showed the result that the genera Epistylis and Vorticella ( Vorticella genus ) may not be monophyletic. It is thought that the morphological features, which have been used for the classification of Peritrichia, a phylogenetic systematics insufficient. Before any other features are found, according to which the different groups can be distinguished from each other, it is not possible to revise the taxa.