Astyanax clavitaeniatus

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Astyanax clavitaeniatus
Astyanax clavitaeniatus illustration.png
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Scientific classification OOjs UI icon edit-ltr.svg
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Class: Actinopterygii
Order: Characiformes
Family: Characidae
Genus: Astyanax
Species:
A. clavitaeniatus
Binomial name
Astyanax clavitaeniatus
Garutti, 2003

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 .

Contents

While it lacks an assessment from the IUCN, A. clavitaeniatus shares features with many species of Astyanax known to be hardy and adaptable (sometimes to a remarkable degree). These similarities, as well as a widespread habitat, indicate a species at low risk. Other elements that may affect its survivability, such as diet and behavior, have not been the subject of extensive research.

Taxonomy

Astyanax clavitaeniatus was described in 2003, alongside Astyanax siapae , as a part of a redescription of congener Astyanax rupununi , which was formerly considered a synonym of Astyanax bimaculatus . [1] All four species are a part of the A. bimaculatus species complex, which also housed roughly a dozen other species when A. clavitaeniatus was described; this number changes regularly, given the complex phyletic relationships therein. [2] As of 2011, the A. bimaculatus species complex contained at least 20 species. [3] (Species in the A. bimaculatus group often share elements of pattern and coloration, including A. clavitaeniatus, but can further be linked by genetic evidence, such as chromosomal makeup. [3] [4] )

Astyanax clativaeniatus has no known synonyms. [5] It also lacks a common name; [6] "club-striped tetra" and "club-striped astyanax" have been suggested based upon its scientific name and physical descriptors.

Etymology

The genus name "Astyanax" is an allusion to the Iliad, though the reason was not made clear in the original text; Astyanax was a warrior of Troy and son of prince Hector. One possibility is that the scales of the type species Astyanax argentatus , which are large and silvery, reminded researchers of armor or a shield, as a warrior might have worn. The species name "clavitaeniatus" comes from Latin, wherein "clava" means "club" and "taenia" means "band" or "stripe", in reference to a dark lateral stripe that gradually thickens towards the tail before tapering off sharply, which results in a club or cudgel shape. [7]

Description

Astyanax clavitaeniatus reaches roughly 7.2 cm (2.8 in) standard length (SL, without the tail fin included). [8] The body is deep, at least 37.4% the length of the body (but usually deeper), and slightly elongated. The caudal peduncle is thick. The snout, slightly pointed, is equal to or less than the diameter of the eye in length. The dorsal fin is situated at the midpoint of the body, and sports 12 rays (3 branched and 9 unbranched). There are 19 caudal-fin rays, 26–32 anal-fin rays, 8 or 9 pelvic-fin rays, and 12 or 13 pectoral-fin rays. [2] Early studies presented clear morphometric differences between A. clavitaeniatus, A. siapae, and A. rupununi, but more modern understandings recognize a great deal of overlap between the three. [9]

The coloration is generally similar to what most species in the A. bimaculatus complex present. Generally, the body ranges from silver to silver-blue or silver-green, with a darker back and paler belly. There is a distinct humeral spot that is rounded or horizontal. Two vertical bars in a dark-brown color are present, with one intersecting the humeral spot and the other 2 or 3 scales behind. In others of the complex, there is often a dark spot on the caudal peduncle that continues onto the fin-rays; A. clavitaeniatus lacks the caudal spot and fin-ray pigmentation, instead presenting with a continued lateral stripe of greatly reduced width (roughly 1/5th of a scale). [10] There are also two silvery spots above the humeral spot, one just in front and one just behind. In alcohol, the coloration remains largely the same, though with plain silver instead of with touches of green or blue. The fins are largely clear. [2]

Sexual dimorphism

In mature males of A. clavitaeniatus, the pelvic and anal fins sport bony hooks on select rays of the anal and pelvic fins; there is no difference in coloration. [2] The presence of bony hooks on some fins is not an uncommon dimorphism in species of Astyanax, but they are rare in other members of the family Characidae. [11] (Only a handful of species of Astyanax, such as A. bagual, demonstrate these hooks on all fins.) [12]

Distribution and ecology

Astyanax clavitaeniatus was originally described from the Surumu river in Roraima, Brazil; paratypes were also collected from the Uraricoera river, in Fazenda Canadá creek and Pau Rocho creek. [2] Other specimens have been collected from the Río Takutu, as well as the Ríos Branco and Negro. [13] All of its habitats are found within the Amazon Basin. [8] Little else has been researched of its ecology, such as diet or behavior.

While it is not known to widely share its habitat with other species of Astyanax, it does live in sympatry with A. rupununi and A. bimaculatus in the Río Takutu. Other sympatric species include members of the genera Hemigrammus, Hyphessobrycon , Jupiaba , and Moenkhausia , as well as the tetra Iguanodectes spilurus . [14]

Conservation status

Astyanax clavitaeniatus has not been evaluated by the IUCN. [8] However, the Chico Mendes Institute for Biodiversity Conservation considers it a species of least concern ("pouco preocupante"). [15] Various similar species of Astyanax, including multiple in the A. bimaculatus complex, are remarkably hardy and adaptable species, which likely remains the case for A. clavitaeniatus. [16]

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<i>Astyanax</i> (fish) Genus of fishes

Astyanax is a genus of freshwater fish in the family Characidae of the order Characiformes. Some of these fish, like many of their relatives, are kept as aquarium pets and known collectively as tetras. With around 150 described species and new ones being described yearly, this genus is among the largest of the entire order; Hyphessobrycon also has more than 145 species and which one is larger at any one time depends on whether more species have been recently described in one or the other. The blind and colorless cave tetra of Mexico is a famous member of the genus, but its taxonomic position is disputed: Some recognize it as part of the Mexican tetra and this is supported by phylogenetic evidence, but others recognize the cave form as a separate species, A. jordani.

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<i>Deuterodon pelecus</i> Species of fish

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<i>Carlastyanax</i> Genus of fishes

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Bryconops munduruku is a small freshwater fish of the family Iguanodectidae that lives in the rivers of South America. Its adipose fin is black, with a clear base, and it has two humeral spots, which is a feature it shares with few congeners. Its fins are a variety of yellow, red, black, and clear, and mature males have hooks on select fin-rays.

<i>Astyanax abramis</i> Species of fish

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<i>Astyanax altiparanae</i> Species of fish

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<i>Astyanax angustifrons</i> Species of fish

Astyanax angustifrons, sometimes referred to as the Campeche tetra, is a small freshwater fish from the rivers of Central and South America. It has a healthy distribution across southern Mexico and northern Guatemala, and is relatively common within its native range. Details regarding its diet and behavior are sparse, but it lives in areas with plentiful riparian vegetation, and most other members of the genus are omnivorous. Its habitat includes places affected by pollution and human activity; nonetheless, it is not endangered.

<i>Astyanax aramburui</i> Species of fish

Astyanax aramburui is a small freshwater fish from the rivers of South America, restricted to a relatively small region within the Paraná and Uruguay river basins of Argentina. It was named after the scientist who established a professional presence for ichthyology in the country, Raúl Arámburu. Considered a near-threatened species by the IUCN, its range includes creeks in a sub-basin affected by various forms of pollution.

<i>Astyanax argyrimarginatus</i> Species of fish

Astyanax argyrimarginatus is a small species of freshwater fish native to various river basins in Brazil. Originally thought to be restricted to the Tocantins-Araguaia river system, a study in 2012 expanded its range to include the Rio Xingu, as well. Specific biotope preferences are unknown, but it is mostly collected from clearwater streams in fairly good health. Its relative abundance and presence in some protected locales means that it is not endangered.

<i>Astyanax asuncionensis</i> Species of fish

Astyanax asuncionensis is a small species of freshwater fish described in 1972 from Asunción, the capital of Paraguay in South America. Its specific epithet is in reference to this. Currently, its range is known to encompass areas of not just Paraguay but also Argentina and Brazil. It is an adaptable, omnivorous species that easily lives in sympatry with various congeners.

<i>Astyanax bagual</i> Species of fish

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.

<i>Astyanax bimaculatus</i> Species of fish

The twospot astyanax, also called the two-spot tetra, is a small species of freshwater fish native to South America. It is a middlingly common tetra in the aquarium industry, with hobbyist reports of its sale and presence, and it is also a well-studied member of the genus Astyanax in wild settings. Amateur aquarists report peaceful schooling behavior in captivity, though fish in wild schools may turn on one another if presented with the threat of a predatory species.

<i>Astyanax biotae</i> Species of fish

Astyanax biotae is a small species of freshwater fish native to various localities in Brazil. It primarily eats invertebrates, like copepods and aquatic fly larvae, and its diet also includes seeds, fruits, and filamentous algae. Its scales are largely silver, with a touch of yellow-brown on the back and a hint of blue on the sides. Like many species of Astyanax, it has a humeral spot, which is a blotch of pigmentation in the area above or around the pectoral fin.

<i>Astyanax bourgeti</i> Species of fish

Astyanax bourgeti is a small species of freshwater fish native to the upper Amazon river in Brazil. Originally described in 1908, it is not a particularly well-studied member of the genus Astyanax, but there is enough information available to establish a native range, an appearance, and potential relationships to congeners; for example, A. bourgeti is a known member of the subgenus Poecilurichthys, and has been considered such for most of its existence. Biotope preferences, sympatry, diet, and behavior are all unknown.

<i>Astyanax brachypterygium</i> Species of fish

Astyanax brachypterygium is a small species of freshwater fish endemic to a collection of high-elevation streams in Brazil. It was named in 2001 alongside congener Astyanax cremnobates, to which it bears a strong resemblance; physical details help to differentiate between the two. Its scales are a greenish-brown on the back and silver on the belly, with reddish fins and a dark humeral spot. One of its defining features is a notably short anal-fin base, which has 13 to 15 rays.

<i>Astyanax brevirhinus</i> Species of fish

Astyanax brevirhinus is a small species of freshwater fish known only from a river basin in northeastern Brazil. It is somewhat understudied and lacks a conservation status, but it is present in a region that is the subject of an ecological restoration project - the Jequitinhonha River. Specifics of diet and behavior are unknown, though shoaling activity has been observed in laboratory conditions.

Astyanax apiaka is a small freshwater fish endemic to the Apiacá river in Mato Grosso, Brazil. Its discovery is recent, as of 2023, which results in little published research of its natural behaviors or preferred biotopes. However, descriptions of its appearance and general environment have been solidified, as well as some baseline information regarding its diet. It lacks a conservation status from the IUCN.

<i>Deuterodon oyakawai</i> Species of fish

Deuterodon oyakawai is a small species of characin endemic to a large river basin along the Atlantic coast in southeast Brazil. It was originally one of three members of the genus Probolodus, but Probolodus is now considered obsolete, synonymized with Deuterodon. Much like other members of Deuterodon, and like some species in related genera, D. oyakawai is a small, silvery fish with fins in some combination of red and clear. It has a defined humeral spot that can be used for identification.

References

  1. ↑ "Citation for Garutti, V. 2003. Revalidação de Astyanax rupununi Fowler, 1914 (Teleostei, Characidae) e descrição de duas espécies novas para o gênero". www.zoobank.org. International Commission on Zoological Nomenclature. Retrieved 29 September 2023.
  2. 1 2 3 4 5 Garutti, Valdener (2003). "Revalidação de Astyanax rupununi Fowler, 1914 (Teleostei, Characidae) e descrição de duas espécies novas para o gênero". Papéis Avulsos de Zoologia. 43 (1). doi: 10.1590/S0031-10492003000100001 . hdl: 11449/22348 .
  3. 1 2 Peres, Wellington Adriano Moreira; Bertollo, Luiz Antonio Carlos; Buckup, Paulo Andreas; Blanco, Daniel Rodrigues; Kantek, Daniel Luis Zanella; Moreira-Filho, Orlando (June 2012). "Invasion, dispersion and hybridization of fish associated to river transposition: karyotypic evidence in Astyanax "bimaculatus group" (Characiformes: Characidae)". Reviews in Fish Biology and Fisheries. 22 (2): 519–526. doi:10.1007/s11160-011-9246-2. S2CID   254979343.
  4. ↑ Dagosta, Fernando C. P.; Marinho, Manoela M. F. (2022). "New small-sized species of Astyanax (Characiformes: Characidae) from the upper rio Paraguai basin, Brazil, with discussion on its generic allocation". Neotropical Ichthyology. 20 (1). doi: 10.1590/1982-0224-2021-0127 . S2CID   247654552.
  5. ↑ Bailly, Nicholas (2017). "Astyanax clavitaeniatus (Garutti, 2003)". WoRMS. World Register of Marine Species . Retrieved 29 Sep 2023.
  6. ↑ "Astyanax clavitaeniatus Garutti, 2003". Encyclopedia of Life . National Museum of Natural History . Retrieved 29 September 2023.
  7. ↑ Scharpf, Christopher; Lazara, Kenneth J. (29 December 2022). "Order CHARACIFORMES: Family CHARACIDAE: Subfamily STETHAPRIONINAE (a-g)". The ETYFish Project. Retrieved 27 September 2023.
  8. 1 2 3 Froese, Rainer; Pauly, Daniel (eds.) (2023). "Astyanax clavitaeniatus" in FishBase . October 2023 version.
  9. ↑ Serra, Wilson (2012). Revisión sistemática del grupo de especies "Astyanax bimaculatus" (Ostariophysi: Characiformes) presentes en Uruguay (Graduate thesis). Universidad de la República, Facultad de Ciencias. Retrieved 1 October 2023.
  10. ↑ Bertaco, Vinicius A.; Garutti, Valdener (March 2007). "New Astyanax from the upper rio Tapajós drainage, Central Brazil (Characiformes: Characidae)". Neotropical Ichthyology. 5 (1): 25–30. doi: 10.1590/S1679-62252007000100003 .
  11. ↑ Camelier, P.; Zanata, A. M. (February 2014). "A new species of Astyanax Baird & Girard (Characiformes: Characidae) from the Rio Paraguaçu basin, Chapada Diamantina, Bahia, Brazil, with comments on bony hooks on all fins". Journal of Fish Biology. 84 (2): 475–490. doi:10.1111/jfb.12295. PMID   24446730.
  12. ↑ Bertaco, Vinícius A.; Vigo, Anelise C. (June 2015). "A new species of Astyanax Baird & Girard (Ostariophysi: Characidae) from the rio Taquari-Antas basin, southern Brazil". Neotropical Ichthyology. 13 (2): 265–272. doi:10.1590/1982-0224-20140145.
  13. ↑ Riuz-C, Raquel I.; Román-Valencia, César; Taphorn, Donald C.; Buckup, Paulo A.; Ortega, Hernán (8 February 2018). "Revision of the Astyanax orthodus species-group (Teleostei: Characidae) with descriptions of three new species". European Journal of Taxonomy (402). doi: 10.5852/ejt.2018.402 .
  14. ↑ de Souza, Lesley S.; Armbruster, Jonathan W.; Werneke, David C. (March 2012). "The influence of the Rupununi portal on distribution of freshwater fish in the Rupununi district, Guyana". Cybium, International Journal of Ichthyology. 36 (1): 34. doi:10.26028/cybium/2012-361-004 . Retrieved 2 October 2023.
  15. ↑ "Astyanax clavitaeniatus Garutti, 2003". ala-bie.sibbr.gov.br. Brazilian Biodiversity Information System. Retrieved 2 October 2023.
  16. ↑ Lobón-Cerviá, Javier; Bennemann, Sirlei (29 September 2000). "Temporal trophic shifts and feeding diversity in two sympatric, neotropical, omnivorous fishes: Astyanax bimaculatus and Pimelodus maculatus in Rio Tibagi (Paraná, Southern Brazil)". Fundamental and Applied Limnology. 149 (2): 285–306. doi:10.1127/archiv-hydrobiol/149/2000/285.
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