Astyanax chaparae
| Astyanax chaparae | |
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| Illustration | |
Scientific classification 
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| Domain: | Eukaryota |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Actinopterygii |
| Order: | Characiformes |
| Family: | Characidae |
| Genus: | Astyanax |
| Species: | A. chaparae
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| Binomial name | |
| Astyanax chaparae Fowler, 1943
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Astyanax chaparae, sometimes called the Chapare tetra, is a small species of freshwater fish only found in Bolivia. It is endemic to its type locality, the Río Chapare, which is a tributary of the Mamoré located in the Cochabamba department. Little else is known of its diet, behavior, and ecology. Its conservation status is similarly unclear, as the IUCN ranks it a data deficient species.
Where other members of the genus Astyanax may sport maxillary teeth, A. chaparae lacks them, which can be used to tell it apart from other members of the genus; for instance, A. chaparae has been noted to resemble congener Astyanax multidens, which was remarked upon in its original description. Further research on its appearance, and its relationships to other members of the genus, is sparse.
Taxonomy[edit]
Astyanax chaparae was first described by American zoologist Henry Weed Fowler in 1943, as one of various nomenclatural acts performed based upon a zoological expedition to Bolivia.[2] (Former congener Knodus mizquae, basionym Astyanax mizquae, was also described from this expedition.)[3] A. chaparae has retained its original name, and has no known synonyms.[4]
The holotype is currently held by the Academy of Natural Sciences at Drexel University, under catalog number ANSP 69194.[5][6]
Etymology[edit]
The genus name "Astyanax" is an allusion to the Iliad, wherein Astyanax was a Trojan warrior. This is thought to lie in the large, shield-like scales of type species Astyanax argentatus, but the reasoning was not made clear in the original text. The species name "chaparae" lies in the type locality of the species - the Río Chapare in the Cochabamba department of Bolivia.[7]
Astyanax chaparae lacks a common name that is widely accepted,[8] but the name "Chapare tetra" has been suggested based on the type locality.[9]
Description[edit]
Astyanax chaparae reaches roughly 3.4 cm (1.3 in) SL (standard length, without the tail fin included). The body is moderately deep, and the eye is wider in diameter than the snout is long. The lateral line has 34 scales. There are 5 rays in the dorsal fin, 23 rays in the anal fin, 14 rays in the pectoral fin, and 6 rays in the ventral fin.[10] A. chaparae lacks maxillary teeth, which can be used to tell it apart from similar congeners (such as A. dolinae and A. multidens).[11] Sexual dimorphism is unknown.
In terms of coloration, A. chaparae is known to resemble A. multidens in life. It has a base silvery body, a bright-silver lateral stripe with a dark stripe above, and fins in some variation of reddish or yellowish. In alcohol, its scales turn a pale fawn color with a lighter belly, while the lateral stripe retains its silver color.[10]
Distribution and ecology[edit]
Astyanax chaparae was originally collected from the Río Chapare in Bolivia, which is a tributary of the Mamoré River;[10] it is endemic to the region.[5][12] It is known to occur at elevations between 200 and 220 m, and inhabits white-water locales with depths influenced by local rainfall.[1] Otherwise, little else is known of its ecology, such as biotope preferences, sympatric species, or diet.
The Rio Chapare, from whence A. chaparae was described, is a relatively narrow river (in comparison to others from the same region) with a meandering pattern. While it used to be responsible for a good deal of sediment deposition in the Mamoré, of which it is a tributary, changes in river dynamics have instead shifted its sediment load into other rivers, largely the Isiboro.[13]
Conservation status[edit]
Astyanax chaparae is listed as data deficient by the IUCN. Because it is known only from the Rio Chapare, no data exists for population trends, threats, or potential conservation buffers.[1]
The Rio Chapare, which is the type locality of A. chaparae, is occupied by an indigenous group - the Yuracare people - that use the riparian forest's resources in such a way to act as conservators rather than consumers, which offers something of a buffer for aquatic species like A. chaparae.[14]
References[edit]
- ^ a b c Carvajal, F.; Maldonado, M.; Sarmiento, J.; Van Damme, P. (2016). "Astyanax chaparae". IUCN Red List of Threatened Species. 2016: e.T49830550A53818523. doi:10.2305/IUCN.UK.2016-1.RLTS.T49830550A53818523.en. Retrieved 27 September 2023.
- ^ "Astyanax chaparae (Fowler, Henry Weed, 1943)". treatment.plazi.org. Plazi TreatmentBank. Retrieved 27 September 2023.
- ^ "Citation for Zoological results of the second Bolivian expedition for the Academy of Natural Sciences of Philadelphia". www.zoobank.org. International Commission on Zoological Nomenclature. Retrieved 27 September 2023.
- ^ Bailly, Nicolas (18 October 2017). "Astyanax chaparae (Fowler, 1943)". WoRMS. World Register of Marine Species. Retrieved 27 September 2023.
- ^ a b Reis, Roberto E.; Kullander, Sven O.; Ferraris Jr., Carl J. (2003). Check List of the Freshwater Fishes of South and Central America. Porto Alegre: Edipucrs. p. 108. ISBN 85-7430-361-5. Retrieved 27 September 2023.
- ^ Luckenbill, Kyle R.; Labadie, Amanda L. (2010). "Digital Imaging of the Primary Type Fish Specimens – Astyanax chaparae". clade.ansp.org. Academy of Natural Sciences, Philadelphia. Retrieved 28 September 2023.
- ^ Scharpf, Christopher; Lazara, Kenneth J. (29 December 2022). "Order CHARACIFORMES: Family CHARACIDAE: Subfamily STETHAPRIONINAE (a-g)". The ETYFish Project. Retrieved 27 September 2023.
- ^ "Astyanax chaparae Fowler 1943". Encyclopedia of Life. National Museum of Natural History. Retrieved 27 September 2023.
- ^ Richardson, Matthew (9 March 2023). Threatened and Recently Extinct Vertebrates of the World: A Biogeographic Approach. Cambridge University Press. ISBN 9781108852586. Retrieved 28 September 2023.
- ^ a b c Fowler, Henry Weed (1 April 1943). "Zoological results of the second Bolivian expedition for the Academy of Natural Sciences of Philadelphia, 1936-1937. Part II.--Additional new fishes". Notulae Naturae (120): 3. ISBN 9781604831207. Retrieved 28 September 2023.
- ^ da Graça, W. J.; Oliveira, C. A. M.; Lima, F. C. T.; da Silva, H. P.; Fernandes, I. M. (October 2017). "A new species of Astyanax (Characiformes: Characidae) from Dolina Água Milagrosa, Rio Paraguai basin, Mato Grosso, Brazil: a new astyanax from rio paraguai basin". Journal of Fish Biology. 91 (4): 1123–1138. doi:10.1111/jfb.13405. PMID 28868674.
- ^ Dagosta, Fernando C.P.; Pinna, Mário De (13 June 2019). "The Fishes of the Amazon: Distribution and Biogeographical Patterns, with a Comprehensive List of Species". Bulletin of the American Museum of Natural History. 2019 (431): 72. doi:10.1206/0003-0090.431.1.1. S2CID 196645665.
- ^ Lombardo, Umberto (10 May 2016). "Alluvial plain dynamics in the southern Amazonian foreland basin". Earth System Dynamics. 7 (2): 453–467. doi:10.5194/esd-7-453-2016.
- ^ Becker, C. Dustin; León, Rosario (10 June 1998). Indigenous Forest Management in the Bolivian Amazon: Lessons from the Yuracare People. Crossing Boundaries, the Seventh Biennial Conference of the International Association for the Study of Common Property. Vancouver, BC, Canada. hdl:10535/847. Retrieved 27 September 2023.