''Jarrellia'' is a genus of

kinetoplastid Kinetoplastida (or Kinetoplastea, as a class) is a group of flagellated protists belonging to the phylum Euglenozoa, and characterised by the presence of a distinctive organelle called the kinetoplast (hence the name), a granule containing a lar ...

s containing a single species, ''Jarrellia atramenti'', described from the blowhole mucus of a

pygmy sperm whale The pygmy sperm whale (''Kogia breviceps'') is one of two extant species in the family Kogiidae in the Physeteroidea, sperm whale superfamily. They are not often sighted at sea, and most of what is known about them comes from the examination of ...

. It is the first flagellate isolated from a marine mammal.

Etymology

The generic name ''Jarrellia'' was chosen in memory of Cheri Jarrell, a volunteer in the Marine Animal Rescue Program at the

National Aquarium in Baltimore The National Aquarium – also known as National Aquarium in Baltimore and many people calling it the Baltimore Aquarium – is a nonprofit public aquarium located at 501 East Pratt Street on Pier 3 in the Inner Harbor area of downtown Baltim ...

, whose collection and archival of samples allowed for the description of this organism. The

specific epithet In Taxonomy (biology), taxonomy, binomial nomenclature ("two-term naming system"), also called binary nomenclature, is a formal system of naming species of living things by giving each a name composed of two parts, both of which use Latin gramm ...

''atramenti'' (meaning 'of ink', genitive case of the Latin noun ''atramentum'' meaning ink) refers to the name 'Inky' that was given to the whale, in reference to the unique ability of

s to release liquid feces in the form of dark reddish-brown clouds of ink when feeding and/or threatened.

Description

''Jarrellia atramenti'' is a species of

, a group of single-celled

flagellate A flagellate is a cell or organism with one or more whip-like appendages called flagella. The word ''flagellate'' also describes a particular construction (or level of organization) characteristic of many prokaryotes and eukaryotes and the ...

s that include many parasites, all characterized by the presence of a

kinetoplast A kinetoplast is a network of circular DNA (called kDNA) inside a mitochondrion that contains many copies of the mitochondrial genome. The most common kinetoplast structure is a disk, but they have been observed in other arrangements. Kinetoplasts ...

. Its cells have two

flagella A flagellum (; : flagella) (Latin for 'whip' or 'scourge') is a hair-like appendage that protrudes from certain plant and animal sperm cells, from fungal spores ( zoospores), and from a wide range of microorganisms to provide motility. Many pr ...

each: a longer anterior flagellum that moves in a whiplash motion, and a shorter posterior flagellum that trails behind when swimming and forms a prominent undulating membrane that extends at least two-thirds the length of the cell body. The tip of this posterior flagellum attaches to the host. The cells move in a

gliding motility Gliding motility is a type of translocation used by microorganisms that is independent of propulsive structures such as flagella, pili, and fimbriae. Gliding allows microorganisms to travel along the surface of low aqueous films. The mechanisms ...

. Inside the cell is an oval nucleus and a fragmented, variably dispersed kinetoplast. It has been observed maturing and undergoing cell division in the blowhole mucus of its host, the

cetacean Cetacea (; , ) is an infraorder of aquatic mammals belonging to the order Artiodactyla that includes whales, dolphins and porpoises. Key characteristics are their fully aquatic lifestyle, streamlined body shape, often large size and exclusively c ...

Kogia breviceps The pygmy sperm whale (''Kogia breviceps'') is one of two extant species in the family Kogiidae in the sperm whale superfamily. They are not often sighted at sea, and most of what is known about them comes from the examination of stranded spec ...

'' (pygmy sperm whale). This organism most closely resembles the genus ''

Trypanoplasma ''Cryptobia'' is a genus of Kinetoplastida, kinetoplastids. Several species are known for being fish pathogens. They can be found in other animals, as well. The name ''Trypanoplasma'' is occasionally used for some of these.Woo, P. T. K. (2003)''Cr ...

'' in terms of motility and morphology, but the structure of the kinetoplast is distinct, as it is unfragmented and rod-like in ''Trypanoplasma'' cells. In addition, ''Trypanoplasma'' have not been observed attaching to host material via a flagellum. The habitat, attachment and kinetoplast structure most resembles that of the

bodonid Bodonida is an order of kinetoplastid flagellate excavates. It contains the genera ''Bodo'' and '' Rhynchomonas'', relatives to the parasitic trypanosomes. This order also contains the colonial genus '' Cephalothamnium''. Taxonomy Bodonida con ...

Cryptobia ''Cryptobia'' is a genus of kinetoplastids. Several species are known for being fish pathogens. They can be found in other animals, as well. The name ''Trypanoplasma'' is occasionally used for some of these.Woo, P. T. K. (2003)''Cryptobia'' (''Try ...

'', but the prominent undulating membrane has not been found in this genus.

Taxonomy

On 25 November, 1993, a stranded juvenile

was rescued from near

Brigantine, New Jersey Brigantine (or simply The Island) is a city in Atlantic County in the U.S. state of New Jersey. As of the 2020 United States census, the city's population was 7,716, a decrease of 1,734 (−18.3%) from the 2010 census count of 9,450, which in ...

and brought to the National Aquarium of Baltimore. The whale was rehabilitated and released to the

Gulf Stream The Gulf Stream is a warm and swift Atlantic ocean current that originates in the Gulf of Mexico and flows through the Straits of Florida and up the eastern coastline of the United States, then veers east near 36°N latitude (North Carolin ...

from Florida on 5 May, 1994. Throughout its six month-long rehabilitation, mucus samples of its blowhole were monitored for microbes, blood cells, and epithelial cells. Among the samples, the new kinetoplastid species was discovered and continuously reported across the months. ''Jarrellia atramenti'' was first identified as a

. Due to its similarities to the bodonid

genera Genus (; : genera ) is a taxonomic rank above species and below family as used in the biological classification of living and fossil organisms as well as viruses. In binomial nomenclature, the genus name forms the first part of the binomial s ...

'' and ''

'' and its unique combination of cellular features, it was proposed as a separate genus. Its description was considered the first published report of a flagellate isolated from a marine

mammal A mammal () is a vertebrate animal of the Class (biology), class Mammalia (). Mammals are characterised by the presence of milk-producing mammary glands for feeding their young, a broad neocortex region of the brain, fur or hair, and three ...

, and among the first reports of trypanoplasm-like kinetoplastids from

warm-blooded Warm-blooded is a term referring to animal species whose bodies maintain a temperature higher than that of their environment. In particular, homeothermic species (including birds and mammals) maintain a stable body temperature by regulating ...

hosts; they were previously considered unable to survive the elevated body temperature of mammals. No molecular data was obtained from this organism. After the split of bodonids into three

orders Order, ORDER or Orders may refer to: * A socio-political or established or existing order, e.g. World order, Ancien Regime, Pax Britannica * Categorization, the process in which ideas and objects are recognized, differentiated, and understood * H ...

Eubodonida ''Bodo'' () is a genus of microscopic kinetoplastids, flagellate excavates first described in 1831 by Christian Gottfried Ehrenberg. The genus is small, as it has recently been redefined to include only four species. ''Bodo'' includes free-livin ...

, Neobodonida and Parabodonida, ''Jarrellia'' was tentatively placed among parabodonids due to its superficial resemblance to ''Trypanoplasma''. However, it was eventually classified as an ''

incertae sedis or is a term used for a taxonomy (biology), taxonomic group where its broader relationships are unknown or undefined. Alternatively, such groups are frequently referred to as "enigmatic taxa". In the system of open nomenclature, uncertainty ...

'' kinetoplastid, as no reliable evidence supports its assignment to one of the orders.

References

External links

{{Discoba Euglenozoa genera Taxa described in 2001