Tintinnid
Encyclopedia
Tintinnids are ciliates of the choreotrich
taxon
Tintinnida, distinguished by vase-shaped shells called lorica
e, which are mostly protein but may incorporate minute pieces of minerals. Although appearing as early as the Ordovician
period, tintinnids became abundant in the fossil record during the Jurassic
. Tintinnids are an important part of the fossil record because of the rarity with which most other ciliates become preserved under the conditions of the marine environment. The loricae of some tintinnids are easily preserved, giving them a relatively good fossil record.
Like other protists, tintinnids are multi-celled (Eukaryota) organisms. Tintinnids are heterotrophic aquatic organisms. They feed primarily on photosynthetic
algae
and bacteria
. They are part of the microzooplankton
(between 20 and 200 micrometre
s in size). Tintinnids are found in marine and freshwaters. However, they are most common in salt water and are usually present in concentrations of about 100 a liter but can reach abundances of several thousand per litre
. Characteristics of their lorica, or shells, are used to distinguish between the roughly 500 species described.
Many species appear to have wide distributions (for example from the Chesapeake Bay
to New Caledonia
) while others are restricted to certain areas, such as arctic waters or coastal seas. Nonetheless, in any given locale dozens of species can be found. Like other members of the microzooplankton (such as oligotrich
ciliates, heterotrophic dinoflagellate
s, radiolarian
s, etc.), tintinnids are a vital link in aquatic food chains as they are the 'herbivore
s' of the plankton. They feed on phytoplankton
(algae and cyanobacteria) and in turn act as food for larger organisms such as copepod
s (small crustacean
s) and larval fish.
The image is a specimen of Dictyocysta mitra from the Bay of Villefranche
in the Mediterranean Sea. The hair-like projections pointing out of the top of the shell are the cilia of the cell. The cilia generate a water flow across the mouth of the cell, bringing food into contact and move the tintinnid. Their swimming pattern is rather 'jumpy'- or dancing- they are part of the 'choreotrichs' which means dancing hairs from their swimming behaviour and cilia.
Choreotrich
The choreotrichs are a group of small, marine ciliates. Their name reflects the impression that they appear to dance . The group includes the tintinnids, which produce species-specific loricae , and are important because these may be preserved as microfossils...
taxon
Taxon
|thumb|270px|[[African elephants]] form a widely-accepted taxon, the [[genus]] LoxodontaA taxon is a group of organisms, which a taxonomist adjudges to be a unit. Usually a taxon is given a name and a rank, although neither is a requirement...
Tintinnida, distinguished by vase-shaped shells called lorica
Lorica (biology)
In biology, a lorica is a shell-like protective outer covering, often reinforced with sand grains and other particles that some protozoans and loricifera metazoans secrete. Usually it is tubular or conical in shape, with a loose case that is closed at one end. An example is the protozoan genus...
e, which are mostly protein but may incorporate minute pieces of minerals. Although appearing as early as the Ordovician
Ordovician
The Ordovician is a geologic period and system, the second of six of the Paleozoic Era, and covers the time between 488.3±1.7 to 443.7±1.5 million years ago . It follows the Cambrian Period and is followed by the Silurian Period...
period, tintinnids became abundant in the fossil record during the Jurassic
Jurassic
The Jurassic is a geologic period and system that extends from about Mya to Mya, that is, from the end of the Triassic to the beginning of the Cretaceous. The Jurassic constitutes the middle period of the Mesozoic era, also known as the age of reptiles. The start of the period is marked by...
. Tintinnids are an important part of the fossil record because of the rarity with which most other ciliates become preserved under the conditions of the marine environment. The loricae of some tintinnids are easily preserved, giving them a relatively good fossil record.
Like other protists, tintinnids are multi-celled (Eukaryota) organisms. Tintinnids are heterotrophic aquatic organisms. They feed primarily on photosynthetic
Photosynthesis
Photosynthesis is a chemical process that converts carbon dioxide into organic compounds, especially sugars, using the energy from sunlight. Photosynthesis occurs in plants, algae, and many species of bacteria, but not in archaea. Photosynthetic organisms are called photoautotrophs, since they can...
algae
Algae
Algae are a large and diverse group of simple, typically autotrophic organisms, ranging from unicellular to multicellular forms, such as the giant kelps that grow to 65 meters in length. They are photosynthetic like plants, and "simple" because their tissues are not organized into the many...
and bacteria
Bacteria
Bacteria are a large domain of prokaryotic microorganisms. Typically a few micrometres in length, bacteria have a wide range of shapes, ranging from spheres to rods and spirals...
. They are part of the microzooplankton
Plankton
Plankton are any drifting organisms that inhabit the pelagic zone of oceans, seas, or bodies of fresh water. That is, plankton are defined by their ecological niche rather than phylogenetic or taxonomic classification...
(between 20 and 200 micrometre
Micrometre
A micrometer , is by definition 1×10-6 of a meter .In plain English, it means one-millionth of a meter . Its unit symbol in the International System of Units is μm...
s in size). Tintinnids are found in marine and freshwaters. However, they are most common in salt water and are usually present in concentrations of about 100 a liter but can reach abundances of several thousand per litre
Litre
pic|200px|right|thumb|One litre is equivalent to this cubeEach side is 10 cm1 litre water = 1 kilogram water The litre is a metric system unit of volume equal to 1 cubic decimetre , to 1,000 cubic centimetres , and to 1/1,000 cubic metre...
. Characteristics of their lorica, or shells, are used to distinguish between the roughly 500 species described.
Many species appear to have wide distributions (for example from the Chesapeake Bay
Chesapeake Bay
The Chesapeake Bay is the largest estuary in the United States. It lies off the Atlantic Ocean, surrounded by Maryland and Virginia. The Chesapeake Bay's drainage basin covers in the District of Columbia and parts of six states: New York, Pennsylvania, Delaware, Maryland, Virginia, and West...
to New Caledonia
New Caledonia
New Caledonia is a special collectivity of France located in the southwest Pacific Ocean, east of Australia and about from Metropolitan France. The archipelago, part of the Melanesia subregion, includes the main island of Grande Terre, the Loyalty Islands, the Belep archipelago, the Isle of...
) while others are restricted to certain areas, such as arctic waters or coastal seas. Nonetheless, in any given locale dozens of species can be found. Like other members of the microzooplankton (such as oligotrich
Oligotrich
The oligotrichs are a group of ciliate protozoa, included among the spirotrichs. They have prominent oral cilia, which are arranged as a collar and lapel, in contrast to the choreotrichs where they form a complete circle. The body cilia are reduced to a girdle and ventral cilia...
ciliates, heterotrophic dinoflagellate
Dinoflagellate
The dinoflagellates are a large group of flagellate protists. Most are marine plankton, but they are common in fresh water habitats as well. Their populations are distributed depending on temperature, salinity, or depth...
s, radiolarian
Radiolarian
Radiolarians are amoeboid protozoa that produce intricate mineral skeletons, typically with a central capsule dividing the cell into inner and outer portions, called endoplasm and ectoplasm. They are found as zooplankton throughout the ocean, and their skeletal remains cover large portions of the...
s, etc.), tintinnids are a vital link in aquatic food chains as they are the 'herbivore
Herbivore
Herbivores are organisms that are anatomically and physiologically adapted to eat plant-based foods. Herbivory is a form of consumption in which an organism principally eats autotrophs such as plants, algae and photosynthesizing bacteria. More generally, organisms that feed on autotrophs in...
s' of the plankton. They feed on phytoplankton
Phytoplankton
Phytoplankton are the autotrophic component of the plankton community. The name comes from the Greek words φυτόν , meaning "plant", and πλαγκτός , meaning "wanderer" or "drifter". Most phytoplankton are too small to be individually seen with the unaided eye...
(algae and cyanobacteria) and in turn act as food for larger organisms such as copepod
Copepod
Copepods are a group of small crustaceans found in the sea and nearly every freshwater habitat. Some species are planktonic , some are benthic , and some continental species may live in limno-terrestrial habitats and other wet terrestrial places, such as swamps, under leaf fall in wet forests,...
s (small crustacean
Crustacean
Crustaceans form a very large group of arthropods, usually treated as a subphylum, which includes such familiar animals as crabs, lobsters, crayfish, shrimp, krill and barnacles. The 50,000 described species range in size from Stygotantulus stocki at , to the Japanese spider crab with a leg span...
s) and larval fish.
The image is a specimen of Dictyocysta mitra from the Bay of Villefranche
Villefranche-sur-Mer
Villefranche-sur-Mer is a commune in the Alpes-Maritimes department in the Provence-Alpes-Côte d'Azur region on the French Riviera.-Geography:...
in the Mediterranean Sea. The hair-like projections pointing out of the top of the shell are the cilia of the cell. The cilia generate a water flow across the mouth of the cell, bringing food into contact and move the tintinnid. Their swimming pattern is rather 'jumpy'- or dancing- they are part of the 'choreotrichs' which means dancing hairs from their swimming behaviour and cilia.