Come friends today we will learn about zooflagellates. Zooflagelados or zoomastigophores are multicellular organisms characterized by the lack of chromosomes of unicellular organisms. Most have one to several flagella, although some may lack these, usually amoeboid forms.

They are mainly parasitic. Its classification is mainly based on the presence and number of flagella, as well as other structures such as lorigae and cytocolor.

In traditional taxonomy, zooflagellates were a class within the phylum Protozoa. This group consisted of extremely diverse species that shared only the absence of chromoplasts and other structures of phytoflagellates.

It was divided into at least seven orders. The group of zooflagellates currently lacks taxonomic validity due to their polyphyletic status.



A flagellum is a long, whip-like, mobile appendage of the same thickness in its extension and with a rounded apex. Its central part is formed by a structure called axonema.

The axoneme is formed by a series of proteinaceous microtubules arranged in pairs, a central pair surrounded by nine concentric pairs.

At the base of the flagellum is a structure similar to a centriole called the basal body, blepharoplasty or kinetosome.

Flagella beat or move in a helical form, which allows the organism to move. This movement is achieved thanks to the contraction and dilation of the proteins that make up the microtubules.

loriga or lorica

Loriga is a protective surface structure secreted by many species of protozoa. The chemical composition of Loriga is very variable, it can be protein, siliceous, calcareous, mucopolysaccharide.

It may also consist of various materials such as sand grains, chocolatocorridos, among others, cemented according to a regular pattern. The shape can be capsule, bell, vitreous, arborescent, among others.

necklace or cytocolor

The necklace is a crown-shaped structure found around the base of the flagellum. This structure is formed by finger-like cell extensions called microvilli and which are covered with mucus. Its function is to increase the cell exchange surface of zooflagellates.


In traditional taxonomy, the class Zoomastigophore or Zooflagellate is composed of the following groups:


Group of aquatic geoflagellates. They feature a single flagellum and an open cage-shaped loriga, at the end of which are found the flagellum and collar.

They may be swimmers or may be fixed to the substrate by means of a peduncle. In sessile conoflagellates, the peduncle is opposite where the flagellum originates.

Currently this group is still considered valid, although it is considered to be a class (Choenoflageltiae) within the phylum Chonanzoa, kingdom Protista or Protozoa. It is made up of about 150 species spread over about 50 species.


In the classical taxonomy, rhizomastiginae are zooflagellates with pseudopods and one to four flagella (sometimes without flagella), which occur together or at different stages of their life cycle.

The group consists mainly of free-living species. Organisms of this taxa are currently confined to a single genus, Rhizomastix .

All species included in this genus are monoflagellates, without mitochondria, and the endosymbionts of insects and amphibians. Another characteristic of these species is the conversion of the collar into a structure called the rhizostyl. An ordering within the phylum Amoebozoa (Protista).


They present two to four flagella. The kinetoplast (granule containing mitochondrial DNA and attached to the base of flagella) is self-replicating. They are stained with silver and Fulgen’s reagent.

They currently form a class (Kinetoplasty) of the phylum Euglenozoa (Protista), and include species found in soil and in aquatic environments, parasitic species of animals including humans, and plants.


Reteromonadinos are presented by presenting two to four flagella. One of the flagella is bent towards the posterior end and is attached to a cytostomy (a type of cellular mouth) that is located ventrically.

In the current classification the group is restricted to two styles, Retortamonas with two flagella and Chilomastix with four. The species is thought to be mainly commensal, although they may be free-living. Form a class (Retortomondida) within the Metamonda phylum (Protista).


They feature bilateral symmetry, with repeated cellular components on each side of the cell and four flagella, arranged symmetrically with respect to the main axis of the body. They are usually parasites.

This group is currently located in the class Diplomenadida, phylum Metamonsada, State Protista.


With two to six flagella, one of which curves towards the posterior end. They are a symbiosis of parasites and insects that feed on wood.

The current taxonomic status of Trichomonads is: Trichomonadida class, Metamonsada phylum, Protista kingdom. The present-day parasitic vertebrate species are also included.


Zooflagellates can cause various diseases in plants and animals, including humans. Among the diseases that can cause the latter:


The zooflagellate is a sexually transmitted disease caused by Trichomonas vaginalis ( Tricomonadinos ). The disease may be asymptomatic or present with symptoms that include unusually abundant vaginal discharge, light green or brown, nausea and bubbling, itching, burning, or redness of the vulva and vagina.

In men, it causes effusion of the penis, burning during urination, prostate and urethral pain. Bladder irritation can happen to both sexes. Infection in men can last for about two weeks; in women, the parasite persists even when there is no treatment with metrovidazole.


Giardiasis is a diarrheal disease caused by the zooflagellate Giardia intestinalis (Diplomonadino). The disease is spread through contact with contaminated water, contaminated food, contact with sick people or eating utensils, as well as by having unprotected anal sex.

The disease may be asymptomatic or present as diarrhea with pasty or liquid stools, nausea, mucus, convulsions and malaise.

Other symptoms may include abdominal pain, nausea, and loss of appetite. Treatment includes secnidazole, metronidazole, tinidazole, furazolidone, albendazole or nitazoxide.

diseases caused by kinetoplastids

Kinetoplastids of the order Trypanosomatida are generally very aggressive parasites. They present complex life cycles involving more than one host.

The life cycle of these species consists of several stages, each with different body forms. They are responsible for various diseases that affect human beings.

These include African trypanosomiasis or sleeping sickness, Chagas disease transmitted by the tess-tee fly, transmitted by triatomine insects, and both caused by species of the genus Trypanosoma .

Another disease is leishmaniasis, which is caused by the species Leishmania and transmitted by sand worms.