''Chalceus guaporensis'' is a species of freshwater fish in the family

Chalceidae Chalceidae, the tucanfishes, is a family of freshwater fish first described by Henry Weed Fowler in the year 1958. It is a monotypic family, home only to the genus ''incertae sedis'' ''Chalceus''. All members of the family inhabit areas of nort ...

that inhabits northern

South America South America is a continent entirely in the Western Hemisphere and mostly in the Southern Hemisphere, with a relatively small portion in the Northern Hemisphere at the northern tip of the continent. It can also be described as the southe ...

. Alongside '' C. epakros'' and '' C. spilogyros'', it was added to the genus ''

Chalceus ''Chalceus'' is a genus of fish that inhabits freshwater habitats in South America. Members can be found in the Amazon and Orinoco basins, as well as in the Guianas and various tributaries of the former. It is the sole representative of the fam ...

'' in the year 2004.

Description

Visually, ''C. guaporensis'' is similar to other ''Chalceus'' species, with metallic scales and a vivid caudal fin (often reddish or pinkish). It is also within the average size range of the genus, reaching 17.4 cm SL. It has a darker stripe down each side that reaches the caudal peduncle; ''C. guaporensis'' and ''C. epakros'' are the only two members of the genus ''Chalceus'' to sport this lateral stripe, differentiating them from the other three. ''C. guaporensis'' also usually has humeral spots (a dark spot above each pectoral fin), but they are not as well-defined as those in ''C. spilogyros'' or ''C. epakros.'' ''C. guaporensis'' and ''C. epakros'' share a more elongated and pointed snout than other ''Chalceus'' species, but it is more pronounced in ''C. epakros''.Zanata, Angela M. and Vari, Richard P
The family Alestidae (Ostariophysi, Characiformes): a phylogenetic analysis of a trans-Atlantic clade
Zoological Journal of the Linnean Society (2005). ''Chalceus guaporensis'' and ''C. epakros'' also both lack a

fontanel A fontanelle (or fontanel) (colloquially, soft spot) is an anatomical feature of the infant human skull comprising soft membranous gaps ( sutures) between the cranial bones that make up the calvaria of a fetus or an infant. Fontanelles allow f ...

(soft, membranous spot) between the parietal and frontal bones of the head. However, ''C. guaporensis'' has seven pelvic fin rays, as opposed to eight in other ''Chalceus'' species, which is the most certain method of visual identification.

Etymology

The specific name ''guaporensis'' is from the

Guaporé River Guaporé River ( pt, Rio Guaporé, es, Río Iténez) is a river in western Brazil and northeastern Bolivia. It is long; of the river forms the border between Brazil and Bolivia. The Guaporé River is part of the Madeira River basin, which eve ...

Bolivia , image_flag = Bandera de Bolivia (Estado).svg , flag_alt = Horizontal tricolor (red, yellow, and green from top to bottom) with the coat of arms of Bolivia in the center , flag_alt2 = 7 × 7 square p ...

, one of ''C. guaporensis's'' habitats, with the Latin suffix "-ensis" denoting a place of origin; compare ''Lynx canadensis'', the

Canada lynx The Canada lynx (''Lynx canadensis''), or Canadian lynx, is a medium-sized North American lynx that ranges across Alaska, Canada, and northern areas of the contiguous United States. It is characterized by its long, dense fur, triangular ears ...

, or ''Sotalia guianensis'', the

Guiana dolphin The Guiana dolphin (''Sotalia guianensis''), also known as the estuarine dolphin or costero, is a dolphin found in the coastal waters to the north and east of South America, and east of Central America. It is a member of the oceanic dolphin fami ...

. It is the only member of the genus ''Chalceus'' to be named after a location. The genus name ''Chalceus'' comes from the Greek word "chalkos", which means "copper". This in turn is from the original description of the first ''Chalceus'' species, the

pinktail chalceus The pinktail chalceus (''Chalceus macrolepidotus''),U.S. Fish and Wildlife Service. Pinktail Chalceus (Chalceus macrolepidotus) Ecological Risk Screening Summary'. 2018. also called the pinktail characin, is a species of freshwater fish of the fa ...

(''C. macrolepidotus''), wherein

Georges Cuvier Jean Léopold Nicolas Frédéric, Baron Cuvier (; 23 August 1769 – 13 May 1832), known as Georges Cuvier, was a French natural history, naturalist and zoology, zoologist, sometimes referred to as the "founding father of paleontology". Cuvier ...

noted that its scales were coppery ("sometimes golden") when preserved in alcohol.

Taxonomy

''Chalceus guaporensis'' was named in the year 2004 by Brazilian biologists Mônica Toledo-Piza and Angela M. Zanata. In the same revision of the genus ''Chalceus'', its congeners ''C. epakros'' and ''C. spilogyros'' were also named. In 2005, ''C. guaporensis'' and ''C. epakros'' were determined to make up a single

clade A clade (), also known as a monophyletic group or natural group, is a group of organisms that are monophyletic – that is, composed of a common ancestor and all its lineal descendants – on a phylogenetic tree. Rather than the English term, ...

. There are five accepted species of ''Chalceus''; the other two are the

(''C. macrolepidotus'') and the yellowfin chalceus (''C. erythrurus''). The former of these is the

type species In zoological nomenclature, a type species (''species typica'') is the species name with which the name of a genus or subgenus is considered to be permanently taxonomically associated, i.e., the species that contains the biological type specimen ...

of ''Chalceus.''

Habitat

Like the rest of the genus ''Chalceus'', ''C. guaporensis'' lives in northern South America. It gets its scientific name because it lives in the

in Bolivia, but it also lives in the

Madre de Dios River The Madre de Dios River () is a river shared by Bolivia and Peru which is homonymous to the Peruvian region it runs through. On Bolivian territory it receives the Beni River, close to the town of Riberalta, which later joins with the Mamore Rive ...

in Peru and the

Madeira River The Madeira River ( pt, Rio Madeira, link=no ) is a major waterway in South America. It is estimated to be in length, while the Madeira-Mamoré is estimated near or in length depending on the measuring party and their methods. The Madeira is ...

in Brazil. It is considered

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 elsew ...

to these areas. The only other ''Chalceus'' species to occur in the Guaporé River is the pinktail. Despite many similarities and a close genetic relationship to ''C. epakros'', the habitat of ''C. guaporensis'' is more restricted, and the two are not found in the same places. This is thought to either be due to competition between the species, or due to slightly different environmental needs. In contrast to how limited ''C. guaporensis'' is concerning where it lives, ''C. epakros'' is the most widespread member of the genus ''Chalceus''.

Diet and behavior

''Chalceus guaporensis'' is largely a

myrmecophagous Myrmecophagy is a feeding behavior defined by the consumption of termites or ants, particularly as pertaining to those animal species whose diets are largely or exclusively composed of said insect types. Literally, myrmecophagy means "ant eating" ...

insectivore A robber fly eating a hoverfly An insectivore is a carnivorous animal or plant that eats insects. An alternative term is entomophage, which can also refer to the human practice of eating insects. The first vertebrate insectivores wer ...

, targeting

ants Ants are Eusociality, eusocial insects of the Family (biology), family Formicidae and, along with the related wasps and bees, belong to the Taxonomy (biology), order Hymenoptera. Ants evolved from Vespoidea, vespoid wasp ancestors in the Creta ...

and the aquatic larvae of moths and butterflies (Lepidoptera), though it also eats beetles, crickets, and some plant material.

References

{{Taxonbar, from=Q950020 Chalceidae Marine fauna of South America Fish described in 2004