A polyp in zoology is one of two forms found in the phylum Cnidaria, the other being the medusa. Polyps are roughly cylindrical in shape and elongated at the axis of the vase-shaped body. In solitary polyps, the aboral end is attached to the substrate by means of a disc-like holdfast called a pedal disc, while in colonies of polyps it is connected to other polyps, either directly or indirectly. The oral end contains the mouth, and is surrounded by a circlet of tentacles.
A unicellular organism, also known as a single-celled organism, is an organism that consists of a single cell, unlike a multicellular organism that consists of multiple cells. Organisms fall into two general categories: prokaryotic organisms and eukaryotic organisms. Most prokaryotes are unicellular and are classified into bacteria and archaea. Many eukaryotes are multicellular, but some are unicellular such as protozoa, unicellular algae, and unicellular fungi. Unicellular organisms are thought to be the oldest form of life, with early protocells possibly emerging 3.5–4.1 billion years ago.
The Colpodea are a class of ciliates, of about 200 species common in freshwater and soil habitats. The body cilia are typically uniform, and are supported by dikinetids of characteristic structure, with cilia on both kinetosomes. The mouth may be apical or ventral, with more or less prominent associated polykinetids. Many are asymmetrical, the cells twisting sideways and then untwisting again prior to division, which often takes place within cysts. Colpoda, a kidney-shaped ciliate common in organic rich conditions, is representative.
Pillar coral is a hard coral found in the western Atlantic Ocean and the Caribbean Sea. It is the only species in the monotypic genus Dendrogyra. It is a digitate coral -that is, it resembles fingers or a cluster of cigars, growing up from the sea floor without any secondary branching. It is large and can grow on both flat and sloping surfaces at depths down to 20 m (65 ft). It is one of the few types of hard coral in which the polyps can commonly be seen feeding during the day.
White band disease is a coral disease that affects acroporid corals and is distinguishable by the white band of exposed coral skeleton that it forms. The disease completely destroys the coral tissue of Caribbean acroporid corals, specifically elkhorn coral and staghorn coral. The disease exhibits a pronounced division between the remaining coral tissue and the exposed coral skeleton. These symptoms are similar to white plague, except that white band disease is only found on acroporid corals, and white plague has not been found on any acroporid corals. It is part of a class of similar disease known as "white syndromes", many of which may be linked to species of Vibrio bacteria. While the pathogen for this disease has not been identified, Vibrio carchariae may be one of its factors. The degradation of coral tissue usually begins at the base of the coral, working its way up to the branch tips, but it can begin in the middle of a branch.
Black band disease is a coral disease in which corals develop a black band. It is characterized by complete tissue degradation due to a pathogenic microbial consortium. The mat is present between apparently healthy coral tissue and freshly exposed coral skeleton.
Tintinnids are ciliates of the choreotrich order Tintinnida, distinguished by vase-shaped shells, the name deriving from a Latin source meaning a small tinkling bell, that are called loricae, which are mostly protein but may incorporate minute pieces of minerals.
Skeletal eroding band (SEB) is a disease of corals that appears as a black or dark gray band that slowly advances over corals, leaving a spotted region of dead coral in its wake. It is the most common disease of corals in the Indian and Pacific Oceans, and is also found in the Red Sea.
Protozoa are a polyphyletic group of single-celled eukaryotes, either free-living or parasitic, that feed on organic matter such as other microorganisms or organic debris. Historically, protozoans were regarded as "one-celled animals".
The ciliates are a group of alveolates characterized by the presence of hair-like organelles called cilia, which are identical in structure to eukaryotic flagella, but are in general shorter and present in much larger numbers, with a different undulating pattern than flagella. Cilia occur in all members of the group and are variously used in swimming, crawling, attachment, feeding, and sensation.
White pox disease, first noted in 1996 on coral reefs near the Florida keys, is a coral disease affecting Elkhorn coral throughout the Caribbean. It causes irregular white patches or blotches on the coral that result from the loss of coral tissue. These patches distinguish white pox disease from white band disease which produces a distinctive white band where the coral skeleton has been denuded. The blotches caused by this disease are also clearly differentiated from coral bleaching and scars caused by coral-eating snails. It is very contagious, spreading to nearby coral.
Yellow-band disease is a coral disease that attacks colonies of coral at a time when coral is already under stress from pollution, overfishing, and climate change. It is characterized by large blotches or patches of bleached, yellowed tissue on Caribbean scleractinian corals.
Colpidium colpoda are free-living ciliates commonly found in many freshwater environments including streams, rivers, lakes and ponds across the world. Colpidium colpoda is also frequently found inhabiting wastewater treatment plants. This species is used as an indicator of water quality and waste treatment plant performance.
Condylostoma is a genus of unicellular ciliate protists, belonging to the class Heterotrichea.
A corallivore is an animal that feeds on coral. Corallivores are an important group of reef organism because they can influence coral abundance, distribution, and community structure. Corallivores feed on coral using a variety of unique adaptations and strategies. Known corallivores include certain mollusks, annelids, fish, crustaceans, flatworms and echinoderms. The first recorded evidence of corallivory was presented by Charles Darwin in 1842 during his voyage on HMS Beagle in which he found coral in the stomach of two Scarus parrotfish.
Zoothamnium niveum is a species of ciliate protozoan which forms feather-shaped colonies in marine coastal environments. The ciliates form a symbiosis with sulfur-oxidizing chemosynthetic bacteria of the species "Candidatus Thiobios zoothamnicoli", which live on the surface of the colonies and give them their unusual white color.
The Folliculinidae are a family of ciliates in the class Heterotrichea, with the common name "bottle-animalcule".
Coral diseases are transmissible pathogens that cause the degradation of coral colonies. Coral cover in reef ecosystems has decreased significantly for a diverse set of reasons, ranging from variable environmental conditions to mechanical breakdowns from storms. In recent years, diseases that infect and kill coral have shown to be a threat to the health of coral reefs. Since the first coral disease was reported in 1965, many different kinds of diseases have popped up in mostly Caribbean waters. These diseases are diverse, including pathogens of bacteria, fungi, viruses, and protozoans. Coral diseases have widespread implications, impacting entire ecosystems and communities of organisms. Researchers are working to understand these diseases, and how potential treatments could stop these pathogens from causing the widespread death of corals in a way that permanently impacts the community structure of reefs.
Zoothamnium is a genus of ciliate protozoan.
Stentor roeselii is a free-living ciliate species of the genus Stentor, in the class Heterotrichea. It is a common and widespread protozoan, found throughout the world in freshwater ponds, lakes, rivers and ditches.
