''Tristramella simonis'', the short jaw tristramella, is a vulnerable species of

cichlid Cichlids are fish from the family Cichlidae in the order Cichliformes. Cichlids were traditionally classed in a suborder, the Labroidei, along with the wrasses ( Labridae), in the order Perciformes, but molecular studies have contradicted this ...

fish from the

Jordan River The Jordan River or River Jordan ( ar, نَهْر الْأُرْدُنّ, ''Nahr al-ʾUrdunn'', he, נְהַר הַיַּרְדֵּן, ''Nəhar hayYardēn''; syc, ܢܗܪܐ ܕܝܘܪܕܢܢ ''Nahrāʾ Yurdnan''), also known as ''Nahr Al-Shariea ...

system, including

Lake Tiberias The Sea of Galilee ( he, יָם כִּנֶּרֶת, Judeo-Aramaic: יַמּא דטבריא, גִּנֵּיסַר, ar, بحيرة طبريا), also called Lake Tiberias, Kinneret or Kinnereth, is a freshwater lake in Israel. It is the lowest ...

(Kinneret), in

Israel Israel (; he, יִשְׂרָאֵל, ; ar, إِسْرَائِيل, ), officially the State of Israel ( he, מְדִינַת יִשְׂרָאֵל, label=none, translit=Medīnat Yīsrāʾēl; ), is a country in Western Asia. It is situated ...

and

Syria Syria ( ar, سُورِيَا or سُورِيَة, translit=Sūriyā), officially the Syrian Arab Republic ( ar, الجمهورية العربية السورية, al-Jumhūrīyah al-ʻArabīyah as-Sūrīyah), is a Western Asian country loc ...

, with introduced populations in the

Nahr al-Kabir The Nahr al-Kabir, also known in Syria as al-Nahr al-Kabir al-Janoubi ( ar, النهر الكبير الجنوبي, lit=the southern great river, by contrast with the Nahr al-Kabir al-Shamali) or in Lebanon simply as the Kebir, is a river in Syria ...

and Orontes basins in Syria. It prefers waters with little or no movement. Along with other

tilapia Tilapia ( ) is the common name for nearly a hundred species of cichlid fish from the coelotilapine, coptodonine, heterotilapine, oreochromine, pelmatolapiine, and tilapiine tribes (formerly all were "Tilapiini"), with the economically most ...

s, ''T. simonis'' is commonly caught as a food fish in parts of its range and it is commercially important in Lake Tiberias.

Conservation status and taxonomy

It is the only member of the

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In the hierarchy of biological classification, genus com ...

Tristramella ''Tristramella'' is a genus of oreochromines, freshwater fishes in the cichlid family. The members of this genus prefer standing waters and their native range is restricted to the Jordan River system, including Lake Tiberias (Kinneret), in Isr ...

'' that remains

extant Extant is the opposite of the word extinct. It may refer to: * Extant hereditary titles * Extant literature, surviving literature, such as ''Beowulf'', the oldest extant manuscript written in English * Extant taxon, a taxon which is not extinct, ...

, but it is vulnerable according to the

IUCN The International Union for Conservation of Nature (IUCN; officially International Union for Conservation of Nature and Natural Resources) is an international organization working in the field of nature conservation and sustainable use of natu ...

. Primary threats are water extraction and

climate change In common usage, climate change describes global warming—the ongoing increase in global average temperature—and its effects on Earth's climate system. Climate change in a broader sense also includes previous long-term changes to E ...

reducing the rain in its range. Other potential threats are uncontrolled fishing, and outbreaks of a

viral disease A viral disease (or viral infection) occurs when an organism's body is invaded by pathogenic viruses, and infectious virus particles (virions) attach to and enter susceptible cells. Structural Characteristics Basic structural characteristics, s ...

that causes blindness in

, including ''T. simonis''. The species survives in less than ten locations. The primary location is Lake Tiberias where it remained common, the population was not threatened and fisheries are well-controlled (unlike other parts of its range). However, in a review of catches in Lake Tiberias, a strong and serious decline was observed in 2006–2016 compared to 1996–2005, which was even more extreme if compared to 1986–1995. If looking at each year in 2000–2015, there was a sudden strong decline to very low levels in 2005–2006, with a slight rebound in 2010, then followed by very low levels again. It likely has the potential to rebound, as small juveniles are still common. Two northern populations, '' intermidia'' from

Lake Hula A lake is an area filled with water, localized in a basin, surrounded by land, and distinct from any river or other outlet that serves to feed or drain the lake. Lakes lie on land and are not part of the ocean, although, like the much larger ...

and '' magdelainea'' from the vicinity of

Damascus )), is an adjective which means "spacious". , motto = , image_flag = Flag of Damascus.svg , image_seal = Emblem of Damascus.svg , seal_type = Seal , map_caption = , ...

, are extinct, but their

taxonomic Taxonomy is the practice and science of categorization or classification. A taxonomy (or taxonomical classification) is a scheme of classification, especially a hierarchical classification, in which things are organized into groups or types. ...

status is uncertain. In the past, they were recognized as

subspecies In biological classification, subspecies is a rank below species, used for populations that live in different areas and vary in size, shape, or other physical characteristics (morphology), but that can successfully interbreed. Not all species ...

of ''T. simonis'' by

FishBase FishBase is a global species database of fish species (specifically finfish). It is the largest and most extensively accessed online database on adult finfish on the web.

and they are still recognized as valid, separate species by the

, which however has not reviewed their status since 2006. Today FishBase and

Catalog of Fishes Catalog of Fishes is a comprehensive on-line database and reference work on the scientific names of fish species and genera. It is global in its scope and is hosted by the California Academy of Sciences. It has been compiled and is continuously up ...

consider both ''intermidia'' and ''magdelainea'' as

synonyms A synonym is a word, morpheme, or phrase that means exactly or nearly the same as another word, morpheme, or phrase in a given language. For example, in the English language, the words ''begin'', ''start'', ''commence'', and ''initiate'' are all ...

of ''T. simonis''. In contrast to the conservation status in much of its native range, a survey in Syria in 2008 found that ''T. simonis'' had been introduced to the

and Orontes basins. It was abundant at some of these locations, even thriving in man-made habitats like reservoirs.

Appearance and behavior

This species can reach a total length of , but adults typically are . It resembles a typical tilapia, usually being overall

olive The olive, botanical name ''Olea europaea'', meaning 'European olive' in Latin, is a species of small tree or shrub in the family Oleaceae, found traditionally in the Mediterranean Basin. When in shrub form, it is known as ''Olea europaea'' ...

–brownish to golden–brownish, sometimes with a banded pattern. Compared to the extinct '' T. sacra'', ''T. simonis'' has a proportionally shorter head and its lower jaw at most protrudes slightly past the upper jaw. They also differ in their teeth (number and shape) and certain

meristics Meristics is an area of ichthyology and herpetology which relates to counting quantitative features of fish and reptiles, such as the number of fins or scales. A meristic (countable trait) can be used to describe a particular species of fish, or us ...

. If recognized as valid, the extinct ''intermidia'' and ''magdelainea'' only differ slightly in proportions and other details compared to ''T. simonis''. ''T. simonis'' mostly feeds on

phytoplankton Phytoplankton () are the autotrophic (self-feeding) components of the plankton community and a key part of ocean and freshwater ecosystems. The name comes from the Greek words (), meaning 'plant', and (), meaning 'wanderer' or 'drifter'. Ph ...

and

macrophytes Aquatic plants are plants that have adapted to living in aquatic environments (saltwater or freshwater). They are also referred to as hydrophytes or macrophytes to distinguish them from algae and other microphytes. A macrophyte is a plant that g ...

, but also takes

zooplankton Zooplankton are the animal component of the planktonic community ("zoo" comes from the Greek word for ''animal''). Plankton are aquatic organisms that are unable to swim effectively against currents, and consequently drift or are carried along by ...

and small

benthic The benthic zone is the ecological region at the lowest level of a body of water such as an ocean, lake, or stream, including the sediment surface and some sub-surface layers. The name comes from ancient Greek, βένθος (bénthos), meaning "t ...

invertebrates. In Lake Tiberias, adults are found in open-water

schools A school is an educational institution designed to provide learning spaces and learning environments for the teaching of students under the direction of teachers. Most countries have systems of formal education, which is sometimes compulsor ...

for much of the year, while the young live in sheltered habitats near the coast. The species can reach maturity when long, and breeding is from March to August, with a female being able to spawn two or three times in a season. It is a

mouthbrooder Mouthbrooding, also known as oral incubation and buccal incubation, is the care given by some groups of animals to their offspring by holding them in the mouth of the parent for extended periods of time. Although mouthbrooding is performed by a va ...

, but some sources indicate this only is done by the female, while others indicate it is done by both parents. There are up to 250 relatively large eggs, which are laid on the open bottom in a "nest" in water less than deep. Shortly after they are picked up in the parent's mouth. The juveniles stay in the mouth after they hatch from the eggs, only leaving their parent when they reach about . Although hybrids are well-known among tilapias, hybrids between ''Tristramella'' and other tilapias are unknown. Despite both living in Lake Tiberias and them being close relatives, hybridization between ''T. simonis'' and the now-extinct ''T. sacra'' also is not known to have occurred. A species of fish louse, '' Argulus tristramellae'', apparently is

host specific In biology and medicine, a host is a larger organism that harbours a smaller organism; whether a parasitic, a mutualistic, or a commensalist ''guest'' (symbiont). The guest is typically provided with nourishment and shelter. Examples include a ...

, only

parasitizing Parasitism is a Symbiosis, close relationship between species, where one organism, the parasite, lives on or inside another organism, the Host (biology), host, causing it some harm, and is Adaptation, adapted structurally to this way of lif ...

''T. simonis'' (even when still common, ''T. sacra'' was not attacked by this fish louse).

References

{{Taxonbar, from=Q1315892

simonis Simonis is both a surname and a given name. Notable people with the name include: *Adrianus Johannes Simonis, Dutch Roman Catholic cardinal and former archbishop of Utrecht *Eugène Simonis or Eugen Simonis, Belgian sculptor and architect *Heide Si ...

Taxonomy articles created by Polbot Taxa named by Albert Günther Fish described in 1864 Sea of Galilee Cichlid fish of Asia Freshwater fish of Western Asia Fish of Israel Fish of Syria