''Rhodeus'' is a genus of freshwater ray-finned fishes belonging to the

family Family (from ) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). It forms the basis for social order. Ideally, families offer predictabili ...

Acheilognathidae, the bitterlings. The

scientific name 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 ...

is derived from the

Greek Greek may refer to: Anything of, from, or related to Greece, a country in Southern Europe: *Greeks, an ethnic group *Greek language, a branch of the Indo-European language family **Proto-Greek language, the assumed last common ancestor of all kno ...

word ', meaning "

rose A rose is either a woody perennial plant, perennial flowering plant of the genus ''Rosa'' (), in the family Rosaceae (), or the flower it bears. There are over three hundred Rose species, species and Garden roses, tens of thousands of cultivar ...

". Most species in the genus are restricted to Asia, but two species are found in Europe (''R. amarus'' and ''R. meridionalis''). Bitterlings are short-lived species, generally surviving only about five years. Their maximum size is 11 cm, but they are usually much shorter. Bitterlings inhabit slow-flowing or still waters, such as ponds, lakes, marshes, muddy and sandy pools, and river backwaters. Because they depend on freshwater mussels to reproduce, their range is restricted. Bitterlings are

omnivorous An omnivore () is an animal that regularly consumes significant quantities of both plant and animal matter. Obtaining energy and nutrients from plant and animal matter, omnivores digest carbohydrates, protein, fat, and fiber, and metabolize ...

, feeding on both invertebrates and plants. Bitterlings have a remarkable reproduction strategy where parents transfer responsibility for the care of their young to various species of freshwater mussels (

Unionidae The Unionidae are a Family (biology), family of freshwater mussels, the largest in the order Unionida, the bivalve molluscs sometimes known as river mussels, or simply as unionids. The range of distribution for this family is world-wide. It is a ...

and

Margaritiferidae Margaritiferidae is a family of medium-sized freshwater mussels, aquatic bivalve molluscs in the order Unionida. Text may have been copied from this source, which is available under Attribution 4.0 International (CC BY 4.0)licence. It is the ...

). The female extends her long

ovipositor The ovipositor is a tube-like organ used by some animals, especially insects, for the laying of eggs. In insects, an ovipositor consists of a maximum of three pairs of appendages. The details and morphology of the ovipositor vary, but typica ...

into the mantle cavity of the mussel and deposits her eggs between the gill filaments. The male then ejects his sperm into the mussel's inhalent water current and fertilization takes place within the gills of the host. The same female may use a number of mussels, and she deposits only one or two yellow, oval eggs into each. Early developmental stages are protected from predation within the body of the mussel. After 3 to 4 weeks, larvae swim away from the hosts to continue life on their own. In 1936, the bitterling was thought to respond to hormones in a pregnant woman's urine, but the work was later discredited.

Species

This genus and ''

Acheilognathus ''Acheilognathus'' iis a genus of freshwater ray-finned fishes belonging to the family Acheilognathidae, the bitterlings. The fishes in this genus are found in Asia. The name is derived from the Greek ''a'', meaning "without", the Greek ''chei ...

'' have a convoluted taxonomic history, one being at times included in the other. They are now considered separate, but some species formerly in ''Rhodeus'' are now in ''Acheilognathus''. These are the currently recognized species in this genus: * '' Rhodeus albomarginatus'' F. Li & Arai, 2014 * '' Rhodeus amarus'' (

Bloch Bloch is a surname of German origin. Notable people with this surname include: A *Adele Bloch-Bauer (1881–1925), Austrian entrepreneur *Albert Bloch (1882–1961), American painter *Alexandre Bloch (1857–1919), French painter *Alfred Bloch ( ...

, 1782) (European bitterling) * '' Rhodeus amurensis'' Vronsky, 1967 * '' Rhodeus atremius'' ( D. S. Jordan & W. F. Thompson, 1914) (Kyushu bitterling) * '' Rhodeus caspius'' Esmaeili, Sayyadzadeh, Japoshvili, Eagderi, Abbasi & Mousavi-Sabet, 2020 * '' Rhodeus colchicus'' Bogutskaya & Komlev, 2001 (Georgian bitterling) * '' Rhodeus cyanorostris'' F. Li, T.-Y. Liao & Arai, 2020 * '' Rhodeus fangi'' (Miao, 1934) * '' Rhodeus flaviventris'' F. Li, Arai & T.-Y.Liao, 2020 * '' Rhodeus haradai'' Arai, N. Suzuki & S. C. Shen, 1990 * '' Rhodeus hondae'' ( D. S. Jordan &

Metz Metz ( , , , then ) is a city in northeast France located at the confluence of the Moselle (river), Moselle and the Seille (Moselle), Seille rivers. Metz is the Prefectures in France, prefecture of the Moselle (department), Moselle Departments ...

, 1913). * '' Rhodeus laoensis'' Kottelat, A. Doi & Musikasinthorn, 1998 * '' Rhodeus lighti'' ( H. W. Wu, 1931) (Light's bitterling) * '' Rhodeus mantschuricus'' T. Mori, 1934 (Amur bitterling) * '' Rhodeus meridionalis'' S. L. Karaman, 1924 (Vardar bitterling) * '' Rhodeus monguonensis'' G. L. Li, 1989 * '' Rhodeus nigrodorsalis'' Li, Liao & Arai, 2020 * '' Rhodeus notatus'' Nichols, 1929 * '' Rhodeus ocellatus'' ( Kner, 1866) (Rosy bitterling) * '' Rhodeus pseudosericeus'' Arai, S. R. Jeon & Ueda, 2001 * '' Rhodeus rheinardti'' ( Tirant, 1883) * '' Rhodeus sciosemus'' (D.S. Jordan & W. F. Thompson, 1914) * '' Rhodeus sericeus'' (

Pallas Pallas may refer to: Astronomy * 2 Pallas asteroid ** Pallas family, a group of asteroids that includes 2 Pallas * Pallas (crater), a crater on Earth's moon Mythology * Pallas (Giant), a son of Uranus and Gaia, killed and flayed by Athena * Pa ...

, 1776) (Amur bitterling) * '' Rhodeus shitaiensis'' F. Li & Arai, 2011 * '' Rhodeus sinensis'' Günther, 1868 * '' Rhodeus smithii'' ( Regan, 1908) * '' Rhodeus spinalis'' Ōshima, 1926 * '' Rhodeus suigensis'' T. Mori, 1935 * '' Rhodeus uyekii'' T. Mori, 1935

Species

References

Further reading