The boxer pupfish (''Cyprinodon simus'') is a small species of

pupfish Pupfish are a group of small killifish belonging to ten genera of the family Cyprinodontidae of ray-finned fish. Pupfish are especially noted for being found in extreme and isolated situations. They are primarily found in North America, South ...

in the family Cyprinodontidae. It is

endemic Endemism is the state of a species being found in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also found els ...

Lake Chichancanab Lake Chichancanab is a lake in Mexico located in the northwest of the state of Quintana Roo, in the municipality of José María Morelos. It is also known as Laguna Chichancanab, Laguna Chicnancanab and Laguna de Chichancanab. It has an approxim ...

Quintana Roo Quintana Roo ( , ), officially the Free and Sovereign State of Quintana Roo ( es, Estado Libre y Soberano de Quintana Roo), is one of the 31 states which, with Mexico City, constitute the 32 federal entities of Mexico. It is divided into 11 mu ...

Mexico Mexico ( Spanish: México), officially the United Mexican States, is a country in the southern portion of North America. It is bordered to the north by the United States; to the south and west by the Pacific Ocean; to the southeast by Guate ...

. In almost all places, different ''

Cyprinodon ''Cyprinodon'' is a genus of pupfishes found in waters that range from fresh to hypersaline. The genus is primarily found in Mexico, the Caribbean Islands and southern United States (Arizona, California, Florida, Nevada, New Mexico, Oklahoma a ...

'' species do not overlap in their range, but there are two notable exceptions and one of these is Lake Chichancanab, which is inhabited by ''C. simus'', '' C. beltrani'', '' C. esconditus'', '' C. labiosus'', '' C. maya'', '' C. suavium'' and '' C. verecundus'' (the other place where several ''Cyprinodon'' species live together are lakes in

San Salvador Island San Salvador Island (known as Watling's Island from the 1680s until 1925) is an island and district of The Bahamas. It is widely believed that during Christopher Columbus's first expedition to the New World, this island was the first land he s ...

, the Bahamas). Living together, the ''Cyprinodon'' species in Lake Chichancanab have diverged into different niches. Pupfish typically feed on algae and

detritus In biology, detritus () is dead particulate organic material, as distinguished from dissolved organic material. Detritus typically includes the bodies or fragments of bodies of dead organisms, and fecal material. Detritus typically hosts commu ...

. In Lake Chichancanab, however, ''C. simus'' has become a

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 ...

-feeder. It once occurred in large

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 compul ...

, but has declined drastically due primarily to

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 the ...

(

Nile tilapia The Nile tilapia (''Oreochromis niloticus'') is a species of tilapia, a cichlid fish native to the northern half of Africa and the Levante area, including Israel, and Lebanon. Numerous introduced populations exist outside its natural range. It i ...

and the

tetra Terrestrial Trunked Radio (TETRA; formerly known as Trans-European Trunked Radio), a European standard for a trunked radio system, is a professional mobile radio and two-way transceiver specification. TETRA was specifically designed for use by ...

Astyanax fasciatus In Greek mythology, Astyanax (; grc, Ἀστυάναξ ''Astyánax'', "lord of the city") was the son of Hector, the crown prince of Troy, and his wife, Princess Andromache of Cilician Thebe."Astyanax". ''Oxford Classical Dictionary''. Oxford, 1 ...

''). Among the endemic ''Cyprinodon'' species in Lake Chichancanab, only ''C. beltrani'' and ''C. labiosus'' still occur in some numbers in their habitat, while the remaining are virtually—if not fully—

extinct in the wild A species that is extinct in the wild (EW) is one that has been categorized by the International Union for Conservation of Nature as known only by living members kept in captivity or as a naturalized population outside its historic range due t ...

(at least some of these, including ''C. simus'', still survive in captivity). However, a specimen of ''C. simus'' was recorded in the wild in 2009.

References

boxeador Endemic fish of Mexico Freshwater fish of Mexico Taxa named by Julian M. Humphries Taxa named by Robert Rush Miller Fish described in 1981 Taxonomy articles created by Polbot {{Cyprinodontiformes-stub