''Chirostoma'' is a genus of Neotropical silversides from the

Lerma River The Lerma River () is Mexico's second longest river. It is a river in west-central Mexico that begins in Mexican Plateau at an altitude over above sea level, and ends where it empties into Lake Chapala, Mexico's largest lake, near Guadalajara, ...

basin in

Mexico Mexico, officially the United Mexican States, is a country in North America. It is the northernmost country in Latin America, and borders the United States to the north, and Guatemala and Belize to the southeast; while having maritime boundar ...

, including lakes Chapala and

Pátzcuaro Pátzcuaro () is a city and municipality located in the state of Michoacán, Mexico. The town was founded sometime in the 1320s, at first becoming the capital of the Purépecha Empire and later its ceremonial center. After the Spanish took over, V ...

. Fish in the genus collectively go by the common name charal/charales in their native range (a name also used for the related '' Poblana''). They are heavily fished, but several of the species have become

threatened A threatened species is any species (including animals, plants and fungi) which is vulnerable to extinction in the near future. Species that are threatened are sometimes characterised by the population dynamics measure of ''critical depensatio ...

due to habitat loss (pollution, water extraction and drought),

introduced species An introduced species, alien species, exotic species, adventive species, immigrant species, foreign species, non-indigenous species, or non-native species is a species living outside its native distributional range, but which has arrived ther ...

and

overfishing Overfishing is the removal of a species of fish (i.e. fishing) from a body of water at a rate greater than that the species can replenish its population naturally (i.e. the overexploitation of the fishery's existing Fish stocks, fish stock), resu ...

. Three species are considered extinct: '' C. bartoni'' (disappeared 2006), '' C. charari'' (1957) and '' C. compressum'' (1900). Four others have not been recorded recently and may also be extinct.

Appearance and behavior

''Chirostoma'' are generally silvery-white, pale gray-brown or dull yellowish in color, and have a long horizontal line on the side of the body (inconspicuous and more spotty in some species). They vary in size, ranging from species that are less than long to species that can surpass . Despite the differences, there is great overlap in the food choice of these

filter feeder Filter feeders are aquatic animals that acquire nutrients by feeding on organic matters, food particles or smaller organisms (bacteria, microalgae and zooplanktons) suspended in water, typically by having the water pass over or through a s ...

s with the main diet being composed of various small organisms (mostly

plankton Plankton are the diverse collection of organisms that drift in Hydrosphere, water (or atmosphere, air) but are unable to actively propel themselves against ocean current, currents (or wind). The individual organisms constituting plankton are ca ...

ic) such as

copepod Copepods (; meaning 'oar-feet') are a group of small crustaceans found in nearly every freshwater and saltwater habitat (ecology), habitat. Some species are planktonic (living in the water column), some are benthos, benthic (living on the sedimen ...

cladocera The Diplostraca or Cladocera, commonly known as water fleas, is a superorder (biology), superorder of small, mostly freshwater crustaceans, most of which feed on microscopic chunks of organic matter, though some forms are predatory. Over 1000 sp ...

ns,

rotifer The rotifers (, from Latin 'wheel' and 'bearing'), sometimes called wheel animals or wheel animalcules, make up a phylum (Rotifera ) of microscopic and near-microscopic Coelom#Pseudocoelomates, pseudocoelomate animals. They were first describ ...

amphipod Amphipoda () is an order of malacostracan crustaceans with no carapace and generally with laterally compressed bodies. Amphipods () range in size from and are mostly detritivores or scavengers. There are more than 10,700 amphipod species cur ...

oligochaete Oligochaeta () is a subclass of soft-bodied animals in the phylum Annelida, which is made up of many types of aquatic and terrestrial worms, including all of the various earthworms. Specifically, oligochaetes comprise the terrestrial megadril ...

nematode The nematodes ( or ; ; ), roundworms or eelworms constitute the phylum Nematoda. Species in the phylum inhabit a broad range of environments. Most species are free-living, feeding on microorganisms, but many are parasitic. Parasitic worms (h ...

s, insect larvae, and fish eggs and embryos (including those of silversides). They are

ovoviviparous Ovoviviparity, ovovivipary, ovivipary, or aplacental viviparity is a "bridging" form of reproduction between egg-laying oviparity, oviparous and live-bearing viviparity, viviparous reproduction. Ovoviviparous animals possess embryos that develo ...

and employ

external fertilization External fertilization is a mode of reproduction in which a male organism's sperm fertilizes a female organism's egg outside of the female's body. It is contrasted with internal fertilization, in which sperm are introduced via insemination and then ...

. During spawning each female lays a few hundred to a few thousand eggs.

Species

There are currently 23 recognized species in this genus. Additionally, the 4 '' Poblana'' species are sometimes included in ''Chirostoma'' instead of being placed in a separate genus. Several species of ''Chirostoma'' can hybridize. * ''

Chirostoma aculeatum ''Chirostoma'' is a genus of Neotropical silversides from the Lerma River basin in Mexico, including lakes Chapala and Pátzcuaro. Fish in the genus collectively go by the common name charal/charales in their native range (a name also used for ...

'' C. D. Barbour, 1973 (Scowling silverside) * ''

Chirostoma arge ''Chirostoma'' is a genus of Neotropical silversides from the Lerma River basin in Mexico, including lakes Chapala and Pátzcuaro. Fish in the genus collectively go by the common name charal/charales in their native range (a name also used for ...

'' ( D. S. Jordan & Snyder, 1899) (Largetooth silverside) * '' Chirostoma attenuatum''

Meek Meekness is an attribute of human nature and behavior that has been defined as an amalgam of righteousness, inner humility, and patience. Meekness has been contrasted with humility alone insomuch as humility simply refers to an attitude towards o ...

, 1902 (Slender silverside) * †'' Chirostoma bartoni'' D. S. Jordan & Evermann, 1896 (Alberca silverside) * '' Chirostoma chapalae'' D. S. Jordan & Snyder, 1899 (Smallmouth silverside) * †'' Chirostoma charari'' ( F. de Buen, 1945) (Least silverside) * †''

Chirostoma compressum ''Chirostoma'' is a genus of Neotropical silversides from the Lerma River basin in Mexico, including lakes Chapala and Pátzcuaro. Fish in the genus collectively go by the common name charal/charales in their native range (a name also used for ...

'' F. de Buen, 1940 * ''

Chirostoma consocium ''Chirostoma'' is a genus of Neotropical silversides from the Lerma River basin in Mexico, including lakes Chapala and Pátzcuaro. Fish in the genus collectively go by the common name charal/charales in their native range (a name also used for ...

'' D. S. Jordan & C. L. Hubbs, 1919 (Ranch silverside) * '' Chirostoma contrerasi'' C. D. Barbour, 2002 (Ajijic silverside) * '' Chirostoma copandaro'' F. de Buen, 1945 * ''

Chirostoma estor ''Chirostoma'' is a genus of Neotropical silversides from the Lerma River basin in Mexico, including lakes Chapala and Pátzcuaro. Fish in the genus collectively go by the common name charal/charales in their native range (a name also used for ...

'' D. S. Jordan, 1880 (Pike silverside) * ''

Chirostoma grandocule ''Chirostoma'' is a genus of Neotropical silversides from the Lerma River basin in Mexico, including lakes Chapala and Pátzcuaro. Fish in the genus collectively go by the common name charal/charales in their native range (a name also used for ...

'' (

Steindachner Franz Steindachner (11 November 1834 in Vienna – 10 December 1919 in Vienna) was an Austrian zoologist, ichthyologist, and herpetologist. He published over 200 papers on fishes and over 50 papers on reptiles and amphibians. Steindachner descri ...

, 1894) (Bigeye silverside) * '' Chirostoma humboldtianum'' (

Valenciennes Valenciennes (, also , , ; ; or ; ) is a communes of France, commune in the Nord (French department), Nord Departments of France, department, Hauts-de-France, France. It lies on the Scheldt () river. Although the city and region experienced ...

, 1835) (Shortfin silverside) * ''

Chirostoma jordani ''Chirostoma'' is a genus of Neotropical silversides from the Lerma River basin in Mexico, including lakes Chapala and Pátzcuaro. Fish in the genus collectively go by the common name charal/charales in their native range (a name also used for ...

'' Woolman, 1894 (Charal) * ''

Chirostoma labarcae ''Chirostoma'' is a genus of Neotropical silversides from the Lerma River basin in Mexico, including lakes Chapala and Pátzcuaro. Fish in the genus collectively go by the common name charal/charales in their native range (a name also used for ...

, 1902 (Sharpnose silverside) * '' Chirostoma lucius'' Boulenger, 1900 (Longjaw silverside) * ''

Chirostoma melanoccus ''Chirostoma'' is a genus of Neotropical silversides from the Lerma River basin in Mexico, including lakes Chapala and Pátzcuaro. Fish in the genus collectively go by the common name charal/charales in their native range (a name also used for ...

Álvarez Álvarez or Álvares may refer to: People *Álvarez (surname), Spanish surname Places * Alvares (river), a river in northern Spain * Alvares (ski resort), in Iran * Alvares, Iran * Alvares, Portugal * Álvarez, Santa Fe, a town in the province of ...

, 1963 (Blunthead silverside) * ''

Chirostoma patzcuaro ''Chirostoma'' is a genus of Neotropical silversides from the Lerma River basin in Mexico, including lakes Chapala and Pátzcuaro. Fish in the genus collectively go by the common name charal/charales in their native range (a name also used for ...

, 1902 (Patzcuaro silverside) * ''

Chirostoma promelas ''Chirostoma'' is a genus of Neotropical silversides from the Lerma River basin in Mexico, including lakes Chapala and Pátzcuaro. Fish in the genus collectively go by the common name charal/charales in their native range (a name also used for ...

'' D. S. Jordan & Snyder, 1899 (Blacknose silverside) * '' Chirostoma reseratum''

, 1963 * ''

Chirostoma riojai ''Chirostoma'' is a genus of Neotropical silversides from the Lerma River basin in Mexico, including lakes Lake Chapala, Chapala and Lake Pátzcuaro, Pátzcuaro. Fish in the genus collectively go by the common name charal/charales in their nativ ...

'' Solórzano & Y. López, 1966 (Toluca silverside) * ''

Chirostoma sphyraena ''Chirostoma'' is a genus of Neotropical silversides from the Lerma River basin in Mexico, including lakes Chapala and Pátzcuaro. Fish in the genus collectively go by the common name charal/charales in their native range (a name also used for ...

'' Boulenger, 1900 (Bigmouth silverside) * '' Chirostoma zirahuen''

, 1902

Culinary use

Dried ''Chirostoma'' can be fried with salt and lemon and covered with fried egg with garlic or chili. They can be added to omelettes or fried pancakes in

green sauce Green sauce or greensauce is a family of cold, uncooked sauces based on chopped herbs, including the Spanish and Italian ''salsa verde'', the French , the German or (Frankfurt dialect), the British mint sauce and greensauce, and the Arg ...

Availability

''Chirostoma'' can be purchased at restaurants on the shores of

Lake Chapala Lake Chapala (, ) has been Mexico's largest freshwater lake since the desiccation of Lake Texcoco in the early 17th century. It borders both the states of Jalisco and Michoacán, being located within the municipalities of Ocotlán, Jalisco, ...

in local markets. They are typically sold dried and are affordable. '' C. estor'' is

aquaculture Aquaculture (less commonly spelled aquiculture), also known as aquafarming, is the controlled cultivation ("farming") of aquatic organisms such as fish, crustaceans, mollusks, algae and other organisms of value such as aquatic plants (e.g. Nelu ...

d, and '' C. humboldtianum'', another potential candidate for aquaculture, has been bred in captivity.

References

{{Authority control Atherinopsidae Extant Pliocene first appearances Taxonomy articles created by Polbot Fish of Mexico Mexican cuisine