| Chalceus epakros | |
|---|---|
 | |
Scientific classification  | |
| Domain: | Eukaryota |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Actinopterygii |
| Order: | Characiformes |
| Family: | Chalceidae |
| Genus: | Chalceus |
| Species: | C. epakros |
| Binomial name | |
| Chalceus epakros Zanata & Toledo-Piza, 2004 | |
Chalceus epakros is a species of freshwater fish in the family Chalceidae, found in northern South America. It is a fairly recent addition to its genus, alongside the species C. guaporensis and C. spilogyros .
Chalceus epakros bears visual similarities to other members of the genus Chalceus , like metallic scales and a vivid red or pink caudal fin, though several differences help separate it from its congeners. It has a thin stripe laterally that reaches the caudal peduncle, as well as a longer and more pointed snout. [1] It may occasionally bear humeral spots (a spot above each pectoral fin), but they are rather indistinct, especially compared to the humeral spots of C. spilogyros . [2] Its fins are a mixture of hyaline and reddish-pink, as opposed to the bright-yellow pelvic fins of C. erythrurus . [3]
Chalceus erythrurus and C. macrolepidotus may occasionally bear a similar lateral stripe to C. epakros, but theirs are broader and more indistinct. [2] It is hypothesized to be related to mating habits, and may be more prominent around mating season. [4] C. epakros' stripe is composed of chromatophores closer to the surface than that of C. erythrurus and others. [1]
Chalceus epakros is incredibly visually similar to C. guaporensis , including a thin lateral stripe, a pointed snout, and the occasional indistinct humeral patch. [4] C. epakros and C. guaporensis are also alike in that they lack a fontanel (soft, membranous spot) on the head, while the other three species have one between the frontal and parietal bone. [4] However, C. guaporensis is slightly larger, and it has 7 pelvic fin rays as opposed to eight on C. epakros. [2] C. epakros is the smallest Chalceus species, reaching 17.4 cm TL (with the caudal fin included); C. guaporensis reaches that same length in SL (without the caudal fin). [5]
The specific name epakros is from Greek, and means "pointed at the end", in reference to the longer and more pointed snout; [1] compare Cryptocentrus epakros, the pointedfin shrimpgoby,
The genus name Chalceus comes from "chalkos", which is the Greek word for copper. [6] French biologist Georges Cuvier, who named the first member of Chalceus (C. macrolepidotus), named it this because the preserved specimen's scales were copper-colored ("sometimes golden") when preserved in alcohol, though its scales are silvery in life. [7] [8]
In the year 2004, Brazilian biologists Mônica Toledo-Piza and Angela M. Zanata performed a re-examination of the genus Chalceus, resulting in the nomination of not only C. epakros but its congeners C. guaporensis and C. spilogyros. [1] Upon study in 2005, C. epakros and C. guaporensis were determined to form a clade, accounting for their visual similarities, while C. spilogyros, C. erythrurus, and C. macrolepidotus share another. [4]
Previously, specimens of C. epakros had been misidentified as specimens of C. macrolepidotus and C. erythrurus; C. macrolepidotus (Cuvier) and C. erythrurus (Cope) are long-established members of the genus, having been named in 1818 and 1870, respectively. [9]
Like the rest of its genus, C. epakros is a freshwater fish from northern South America. [10] C. epakros has the widest distribution of all Chalceus species, inhabiting the Amazon basin, the Orinoco river, and the Essequibo river. [1] [6] Despite sharing a clade, C. epakros and C. guaporensis are not found in the same areas; this could either be due to competition between the species, or due to slight differences in environmental needs. [11]
Chalceus epakros and C. macrolepidotus are the only two Chalceus species known to occur in Guyana. [2]
Chalceus epakros seems to largely be an insectivore, targeting ants and wasps. In one study (Torrente-Vilara et al.), very few examined specimens had food material in their stomachs, making diet-mapping difficult. [11] This lines up with other, more thoroughly-studied Chalceus species, which target similar invertebrate spreads. [12] [13]
Behaviorally, C. epakros is lacking in data. Other members of the genus are active, fast-moving, and somewhat skittish. [14] [15]
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 family Chalceidae.
Astyanax microschemos is a species of characid fish from Brazil. It belongs to the A. scabripinnis species complex and differs from other species outside it by having a lower number of branched anal fin rays and its shallow body depth being about 26.9-29.7 vs more than 35% of its standard length (SL). Compared to species of its own complex, it can be distinguished by the combination of its shallow body depth, and smaller interorbital width. The species name comes from the Greek mikroschemos, meaning "low stature", which refers to the shallow body depth of the animal.
Deuterodon pelecus is a species of characid fish from Brazil. It can be distinguished from other species by: its body depth ; its short and pointed snout smaller than the orbital diameter; and a reduced number of branched anal fin rays. D. pelecus also differs from members of its genus by its characteristic color pattern. It possesses a single humeral spot that is constricted to the region above the lateral line; at the same time it shows a conspicuous midlateral body stripe from opercle to the caudal fin base, an autapomorphy of this precise species. Other Deuterodon species have a humeral spot that is vertically or horizontally elongate and have the midlateral stripe becoming faint near that humeral spot. The species name is derived from the Greek pelekus, meaning "axe", referring to the pigmentation shape resulting from the adjoinment of the humeral spot with the midlateral stripe.
The pinktail chalceus, also called the pinktail characin, is a species of freshwater fish of the family Chalceidae found in South America. It is one of five fish in the genus Chalceus, and is the type species of the genus.
The tucan fish, also called the yellowfin chalceus, is a species of freshwater fish in the family Chalceidae. It is one of five species in the genus Chalceus, and was the second species to be described therein.
Chalceus guaporensis is a species of freshwater fish in the family Chalceidae that inhabits northern South America. Alongside C. epakros and C. spilogyros, it was added to the genus Chalceus in the year 2004.
Chalceus spilogyros, sometimes misspelled as Chalceus spilogyrus, is a species of freshwater fish in the family Chalceidae that inhabits northern South America. It is a relatively new member of the genus Chalceus, along with C. epakros and C. guaporensis.
Bryconops collettei is a small freshwater fish from the rivers of South America. It is mostly silvery, with notable green iridescence on its sides, and a diffuse ocellus (eyespot) on the upper lobe of the caudal fin. Before its distinction as a separate species, specimens of B. collettei were misidentified as specimens of Bryconops caudomaculatus due to several morphological similarities, including a caudal ocellus and generally similar fin coloration.
Bryconops cyrtogaster is a midsize species of freshwater fish found in the Oyapock river in French Guiana and Brazil. It is overall silver, with an indistinct dark patch at the base of the tail fin that spreads onto the fin rays slightly. Originally described in 1926 under a different baisonym, it was the subject of a redescription in June 2020.
Bryconops humeralis is a small freshwater fish distributed across northern South America. The name "humeralis" means "relating to the shoulder", in reference to the distinct humeral patches that the fish sports. It is slightly longer than average in terms of the genus Bryconops, though still firmly within the standard range, and is slightly more slender than is usual for its congeners.
Bryconops melanurus, sometimes called the tail-light tetra, is a small species of freshwater fish from South America that primarily preys on insects. It lives in small schools and is an active swimmer, which means that it requires open space in its habitat. Nonetheless, it does not demonstrate a strong preference for any one biotope within its native range.
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Bryconops vibex is a small freshwater fish from the rivers of Venezuela, known solely from the Rio Cataniapo. The body is slender, though with an element of sturdiness, and it has one humeral spot by each pectoral fin. It bears visual similarities to several congeners, but can be differentiated by way of many factors.
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Bryconops hexalepis is a small iguanodectid fish from the rivers of Brazil. It is solely found in the drainage of the Rio Tocantins. Rather elongate and quite slender, it is considered one of the smaller species of its genus, with tall scales and large eyes.
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Bryconops rheoruber is a species of freshwater fish from the rivers of Brazil. Its back scales are tan-to-cream, and its belly is silvery; the divide between the two colors is marked by a broad iridescent-silver stripe. Its fins are a mixture of pale, clear, and reddish, which contributed to its specific name. "Rheo" means "flow" or "current" in Greek, and "ruber" means "red" in Latin.
Astyanax bagual is a small species of freshwater fish known only from the Taquari-Antas river basin in southern Brazil. It is unusual in the genus Astyanax because mature male specimens display bony hooks on the rays of all fins; in opposition, most others have them on the anal, pelvic, or pectoral fins - sometimes on more than one of these, but very rarely on all fins. It can further be told apart from various congeners by way of dentition and some aspects of coloration, including the presence of two humeral spots instead of one.
Astyanax clavitaeniatus is a small species of freshwater fish native to various rivers in the Amazon basin. It is characterized by a club-shaped lateral stripe, which is where it gets its scientific name; "clava" means "club", and "taenia" means "stripe". It is a deep-bodied fish with a silvery base color, which is not uncommon for members of Astyanax. Its markings - including a humeral spot and two vertical brown bars - indicate that it is a part of a species complex centered around congener Astyanax bimaculatus.
Astyanax anai is a small freshwater fish native to Central America. It has a restricted range, inhabiting a handful of Atlantic drainages in Costa Rica and Panama, and is known from locales only up to 100 meters elevation. As an endangered species, A. anai is a point of interest for conservation biologists studying the region. It can be found living sympatrically with other species of Astyanax, but is less common than its relatives.
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