Biology:Astyanax bimaculatus
Twospot astyanax | |
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Scientific classification ![]() | |
Domain: | Eukaryota |
Kingdom: | Animalia |
Phylum: | Chordata |
Class: | Actinopterygii |
Order: | Characiformes |
Family: | Characidae |
Genus: | Astyanax |
Species: | A. bimaculatus
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Binomial name | |
Astyanax bimaculatus Linnaeus, 1758
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Synonyms[1][2] | |
Astyanax bimaculatus borealis (Eigenmann, 1908) |
The twospot astyanax (Astyanax bimaculatus),[1][3] 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.
Its very earliest report was by prolific taxonomist Carl Linnaeus in 1758, in the 10th edition of Systema Naturae. Linnaeus designated it a member of genus Salmo, and since then it has also been considered a member of the genus Tetragonopterus before being placed in Astyanax. Currently, A. bimaculatus is at the center of a species complex, and specific species relationships are still being deciphered in modern ichthyological studies. As it stands, no monophyly can be guaranteed from A. bimaculatus.
Astyanax bimaculatus is omnivorous, eating plants, zooplankton, and various forms of detritus. It is also known to occasionally target other fish to eat their scales. In turn, A. bimaculatus is regularly preyed upon by Hoplias malabaricus, the trahira, as well as various heron species (genus Ardea). It is also host to a variety of parasites, most often flukes (Monogenea). Further, A. bimaculatus is a farmed fish for human use, such as consumption or bait.
Taxonomy
When first described by Carl Linnaeus in 1758, A. bimaculatus was given the name Salmo bimaculatus.[4][5] Throughout the 1800s, various species were named under the genus Tetragonopterus, all of which were later found to be synonymous with A. bimaculatus.[1][2] In 1912, A. bimaculatus was momentarily considered a species of genus Poecilurichthys.[6][7] The species Tetragonopterus caudomaculatus, today known as Bryconops caudomaculatus,[8] was once mistakenly identified as being a possible synonym or otherwise close relative.[9]
Astyanax bimaculatus is at the center of a species complex and species subgroup bearing its name. The subgroup in question is made up of at least 20 species, all of which are characterized by various morphological similarities.[10] These species include - but are not limited to - A. argyrimarginatus, A. clavitaeniatus, A. goyacensis, A. novae, A. rupununi, A. saltor, A. siapae, A. unitaeniatus, A. utiariti, A. validus, A. abramis, A. maculisquamis, A. borealis, and A. orbignyanus.[11] In past studies of species in this group, it has been simpler for researchers to ignore designations and consider all examined specimens to be examples of A. bimaculatus, delineating by region instead of name.[10]
Genetics
In terms of genetic information, A. bimaculatus is a notably variable species. Chromosomal study reveals a distinct - and complex - cytotype, or arrangement and number of chromosomes, for populations in different regions.[10][12] Genetic diversity in the species is not lowered by the presence of waterfalls or dams that separate different populations.[13] An interesting factor in the chromosomal makeup of A. bimaculatus, specifically populations in the Amazon region, is the presence of a B microchromosome, a particularly small type of chromosome present in some birds, reptiles, and fish;[12] little is known regarding the origin and evolution of B microchomosomes.[14]
In genetic studies, many animals are diploid, which means that chromosomes arrange themselves in pairs. When the variable "n" represents chromosome sets, then a diploid animal's chromosome number is represented by "2n". For A. bimaculatus, which is indeed diploid, this number is 2n=50.[15] (To compare, this number is 2n=46 in humans.) The chromosome number 2n=50 is shared by various other species in the A. bimaculatus complex, such as A. lacustris, A. altiparanae, A. asuncionensis, and A. jacuhiensis.[16]
Etymology
The genus name Astyanax originates in the Iliad, originating from the son of prince Hector, the Trojan warrior Astyanax. The specific reason for this allusion was not made clear in the nominal text, but the large, armor-like scales of type species Astyanax argentatus may be responsible. The specific name bimaculatus means "two-spotted", in reference to the distinct pair of markings - the humeral spot and the spot on the caudal peduncle.[17] These two spots also earn A. bimaculatus the common name "twospot astyanax".[18]
Description
Astyanax bimaculatus reaches a maximum total length of 17.5 cm (6.9 in), and a maximum weight of 91.60 g (3.23 oz).[1] The scales are large, and lack distinct radii originating from a single point in the center of each; the presence of such lines was a trait once ascribed to A. bimaculatus,[19] but has since been recognized as a trait of congener A. abramis instead.[20] There are 33 lateral-line scales, 26–27 dorsal-fin rays, and 26–30 anal-fin rays.[21][22] Before taxonomic revisions, the reported variation in the numbers of fin-rays and lateral-line scales was much greater, due to separate species all being grouped under a single name.[7][23]
The back is dark-green, the sides a silver-yellow, and there is a clear silver lateral stripe. The base of the dorsal fin and the upper lobe of the caudal fin may be strongly red, pink, or yellow, with reduced coloration in the rest of the fin.[24] There is a strong black humeral spot, and another strong blotch of pigment at the base of the caudal fin that extends onto the middle caudal-fin rays; these two spots are shared amongst all members of the A. bimaculatus species complex, which is often considered one of the defining characteristics therein, even if a small handful of species do not conform, including A. elachylepis and A. varzeae.[25] Markings also characteristic of this complex include two brown vertical bars in the humeral region.[26]
Sexual dimorphism
Female specimens of A. bimaculatus are larger than males.[27] Bony hooks also develop on the anal and pelvic fins of sexually mature males during spawning season, then regress afterwards.[28]
Ecology
Diet
Astyanax bimaculatus is an omnivorous fish with a leaning towards plant matter. Roughly 60% of the diet is vegetal in nature, and 40% of animals; of these, dicots are the most prevalent in plants, and insects the most prevalent in animals.[29] However, when presented with a shortage of food, A. bimaculatus is remarkably capable of changing its dietary composition.[30] As a further demonstration of adaptability, A. bimaculatus has been recorded following around another fish species - namely Corydoras polystictus - to take advantage of the invertebrates, detritus, and algae that C. polystictus flushes out during its foraging activity.[31]
Because it mostly eats plant matter, it serves an important role in the food chain, transferring that energy up into the animals that prey upon it. This role also allows it to transmit disease to its predators.[32]
Distribution
Astyanax bimaculatus has an enormous distribution. The rivers and basins it can be found in include, but are not limited to: the Amazonas estuaries and the main channel, Apure, Araguaia, Atrato, Beni-Madre de Dios, Branco, Cauca-Magdalena-Sinu, Coppename, Suriname, Saramacca, Corentyne-Demerara, Essequibo, Guapore, Itapicuru-Mearim, lapura, middle-lower Madeira, Mamore, Maroni-Approuague, Oiapoque, Orinoco (upper and lower), Parnaiba, Purus, Putumayo, upper Tocantins, Ucayali, and upper Xingu.[33]
Though considered sedentary, A. bimaculatus (and members of its species complex) can undertake short-distance migrations if necessary.[34]
Habitat
Because of its remarkable range, A. bimaculatus is tolerant of a wide range of conditions. However, it remains entirely potamodromous (freshwater), and seems to have a preference for water with a pH of 5.5–7.5.[1] Nonetheless, it can stay alive for long periods of time in suboptimal conditions; one example, documented by zoologist William Beebe in 1942, was a wide variety of aquatic life stranded in a pond that had been reduced to a mud puddle in the severe dry season of Caripito, Venezuela. Of 32 A. bimaculatus individuals trapped therein, 12 remained alive in surroundings that should not have sustained them for as long as had already been endured.[24]
Sympatric species
The native range of A. bimaculatus ensures that it will overlap with a great deal of other aquatic species. Its relatively peaceful nature means that it can often coexist without incident, and its dietary flexibility means that ecological competition is unnecessary; if one food item is scarce, it can simply shift targets. As such, environments with high species diversity are not of issue for A. bimaculatus.[30]
One of the most comprehensive lists of species found alongside A. bimaculatus came as a result of William Beebe's discovery of a drying-up pond in Venezuela. Fascinated by the circumstances and by just how many animals had remained alive in such poor conditions, Beebe made an annotated list of all of the species he and his colleagues could identify. Fish species found therein with A. bimaculatus include, but are certainly not limited to: Ochmacanthus flabelliferus, Callichthys callichthys, Hoplosternum littorale, Farlowella acus, Copella arnoldi, Creagrutus beni, Erythrinus erythrinus, Gephyrocharax valencia, Hoplerythrinus unitaeniatus, Pristella maxillaris, and Serrasalmus eigenmanni. Also in the same location were Pipa pipa, the common Surinam toad, and Rhinoclemmys punctularia, the spot-legged wood turtle.[24]
Astyanax bimaculatus has further been collected at turbid-water sites that host Crenicichla britskii, Aphyocheirodon hemigrammus, Hemigrammus marginatus, Hyphessobrycon eques, Gymnocorymbus thayeri, Ctenobrycon hauxwellianus, and Pyrrhulina vittata.[35][36]
Parasites
Astyanax bimaculatus is a host to various parasites that colonize different parts of the body. Creptotrema dissimilis is a species of trematode (flatworm) that inhabits the intestines. Magnivitellinum simplex, another intestinal trematode, was first described from A. bimaculatus in Brazil.[37] Parasitic isopod Livoneca lazzari was also first described from A. bimaculatus, this time from the gill cavity.[38] The parasites most likely to infect A. bimaculatus come from Monogenea, a class of parasitic flatworms, and infections are more common during the rainy seasons.[39]
Eukaryotic microparasites of the genus Myxobolus have been found inhabiting the gill filaments of A. bimaculatus, but the disease it causes is asymptomatic for A. bimaculatus.[40]
Biology
Astyanax bimaculatus can reach up to 18 years of age.[1]
Reproduction
Astyanax bimaculatus is capable of year-round reproduction, though they are less likely to be in an active reproductive or maturation state during May, June, and July. In times of scarcity, energy resources can be diverted from the bodily fat or from the liver to the gonads of female specimens; males do not use the same strategy.[41] Males also demonstrate reproductive morphology considered to be more "primitive" in phylogeny, including how the sperm cells are formed and carried.[42] The peak of the spawning period, while it may depend on location, has been recorded in January and February.[43]
Female specimens exposed to a chemical signal called "conspecific alarm substance", released by other A. bimaculatus in stressful situations like a predator attack, ovulate earlier than those not exposed - but they only ovulate once, and the generated zygotes may not develop.[44] In normal spawning conditions, larger females can lay larger numbers of eggs, simply because they have more space to carry them.[43] The eggs of A. bimaculatus are weakly adhesive, and are laid in environments of low current.[45]
Spawning has been achieved in captivity.[46]
Role as bioindicator
Wastewater, animal pollutants, and pesticides can all have a negative impact on a given aquatic environment. Specifically, these factors may be genotoxic, which means that they can damage cell "building blocks" and lead to harmful mutations (such as cancer). A. bimaculatus can be used as a biological indicator (bioindicator) of pollutants that may be genotoxic, based upon the formation of micronuclei in the red blood cells.[47] The presence of a micronucleus results from a chromosome (or chromosome fragment) that is not carried into one of the nuclei that forms during cell division, essentially being "left behind"; this is a sign of genotoxicity.
Enzymes from kidney, gill and brain tissues of A. bimaculatus can also be tested to measure environmental impact. The enzymes that are higher or lower depend on factors from the surrounding environment, such as low oxygen, so measurements therein can indicate changes in water parameters and various pollutants.[48]
Behavior
Astyanax bimaculatus is generally non-competitive and will make changes in its own behavior so that its niche is not interfered with by sympatric species; this includes environment usage and components of dietary intake.[49] Generally, it swims in schools, which increases survival for many animal species that live in groups. Laboratory testing has introduced a caveat to this, however. It displays conspecific aggression when faced with the threat of an active, chasing predator. Because predators are known to target the weakest or most isolated of a group, purposefully wounding a group member gives the predator in question an easy target, which increases the survival chances of the others.[50]
Presence and behavior in aquaria
Astyanax bimaculatus is kept in captivity both by hobbyists and by scientists. In hobbyist circles, A. bimaculatus is a species known to need ample swimming space, and should not be paired with more retiring fish given its "rambunctious" habits.[51] Generally, however, it is non-aggressive.[52]
Researchers have experimented with using lactic acid bacteria from the intestinal tract of A. bimaculatus as a probiotic supplement for captive fish. Preliminary laboratory results are promising.[53] In turn, turmeric (Curcuma longa) has been shown to have positive histological effects on A. bimaculatus, resulting in decreased parasite activity.[54] Various anesthetics have been tested for efficacy on A. bimaculatus, which can help reduce stress levels during aquacultural procedures in captivity. An organic compound called 2‐phenoxyethanol, as well as the essential oils of tea trees (Melaleuca alternifolia) and African basil (Ocimum gratissimum), have all proven effective on captive specimens; such results can be used to inform similar tests on other captive fish to ensure welfare.[55]
Conservation status
Astyanax bimaculatus has not been evaluated by the IUCN.[1] Nonetheless, there is almost no risk of it becoming endangered, as it is remarkably widespread and incredibly adaptable. The construction of hydroelectric dams in its native range, for example, has not depressed population numbers; in one study, populations from above and below a dam simply developed different morphological properties to cope with the changes in flow, environment, and food availability.[56] Changes in accessible dietary components also do not impede A. bimaculatus populations, as they are prepared to take advantage of whatever food sources may be nearby, given opportunistic feeding habits.[30]
References
- ↑ 1.0 1.1 1.2 1.3 1.4 1.5 1.6 Froese, Rainer and Pauly, Daniel, eds. (2023). "Astyanax bimaculatus" in FishBase. May 2023 version.
- ↑ 2.0 2.1 Bailly, Nicolas (2017). "Astyanax bimaculatus (Linnaeus, 1758)". WoRMS. World Register of Marine Species. http://www.marinespecies.org/aphia.php?p=taxdetails&id=1023047.
- ↑ "Astyanax bimaculatus (Linnaeus, 1758)". Species 2000: Naturalis, Leiden, the Netherlands. https://www.catalogueoflife.org/data/taxon/J5QG.
- ↑ Linné, Carl von; Salvius, Lars (1758). Caroli Linnaei... Systema naturae per regna tria naturae: secundum classes, ordines, genera, species, cum characteribus, differentiis, synonymis, locis. Holmiae: Impensis Direct. Laurentii Salvii. pp. 311–312. doi:10.5962/bhl.title.542. https://www.biodiversitylibrary.org/bibliography/542.
- ↑ "Salmo bimaculatus". Species. GBIF. http://www.gbif.org/species/2353036.
- ↑ Eigenmann, Carl H. (1912). The freshwater fishes of British Guiana, including a study of the ecological grouping of species and the relation of the fauna of the plateau to that of the lowlands. Pittsburgh: Carnegie Institute. pp. 359–361. doi:10.5962/bhl.title.4686. http://www.biodiversitylibrary.org/bibliography/4686.
- ↑ 7.0 7.1 Fowler, Henry W. (1915). "Cold-blooded vertebrates from Florida, the West Indies, Costa Rica, and eastern Brazil". Proceedings of the Academy of Natural Sciences of Philadelphia 67: 263. https://www.biodiversitylibrary.org/page/1708669. Retrieved 30 May 2023.
- ↑ "Bryconops caudomaculatus". Species. GBIF. http://www.gbif.org/species/2354277.
- ↑ Fowler, Henry w. (1906). "Further Knowledge of some Heterognathous Fishes; Part II". Proceedings of the Academy of Natural Sciences of Philadelphia 58: 432–433. https://www.biodiversitylibrary.org/page/6390572. Retrieved 30 May 2023.
- ↑ 10.0 10.1 10.2 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)" (in en). Reviews in Fish Biology and Fisheries 22 (2): 519–526. doi:10.1007/s11160-011-9246-2. ISSN 0960-3166. http://link.springer.com/10.1007/s11160-011-9246-2.
- ↑ "Astyanax lacustris Lutken 1875 - Plazi TreatmentBank" (in en). https://treatment.plazi.org/id/BA6B87DF-FF97-0E73-FF56-F8DCA7CBFE80.
- ↑ 12.0 12.1 Corrêa de Sousa, Rodrigo Petry; dos Santos, Jaymeson Lielson Anjos; Silva‐Oliveira, Gláucia Caroline; Furo, Ivanete de Oliveira; de Oliveira, Edivaldo Herculano Corrêa; Vallinoto, Marcelo (February 2023). "Characterization of a new cytotype and ocurrence [sic of a B microchromosome in two spot astyanax, Astyanax bimaculatus Linnaeus, 1758 (Characiformes: Characidae)"] (in en). Journal of Fish Biology 102 (2): 520–524. doi:10.1111/jfb.15265. ISSN 0022-1112. PMID 36321966. https://onlinelibrary.wiley.com/doi/10.1111/jfb.15265.
- ↑ Paiva, Samuel Rezende; Dergam, Jorge Abdala; Machado, Flávia (May 2006). "Determining Management Units in Southeastern Brazil: The Case of Astyanax bimaculatus (Linnaeus, 1758) (Teleostei: Ostariophysi: Characidae)" (in en). Hydrobiologia 560 (1): 393–404. doi:10.1007/s10750-005-9415-1. ISSN 0018-8158. http://link.springer.com/10.1007/s10750-005-9415-1.
- ↑ Sampaio, Tatiane R.; Gouveia, Juceli G.; da Silva, Carlos R.M.; Dias, Ana L.; da Rosa, Renata (2015). "Molecular Analysis of the B Microchromosome in Steindachnerina insculpta (Characiformes: Curimatidae) by Microdissection" (in en). Cytogenetic and Genome Research 146 (1): 51–57. doi:10.1159/000381932. ISSN 1424-8581. PMID 25999244. https://www.karger.com/Article/FullText/381932.
- ↑ Fava, Lucioni (28 March 2008). Variação cariotípica de Astyanax bimaculatus (Linnaeus, 1758) (Pisces: Characidae) nas bacias costeiras do Brasil (Master's thesis) (in português). Universidade Federal de Viçosa. S2CID 201212813.
- ↑ Gavazzoni, Mariane; Paiz, Leonardo M.; Oliveira, Carlos A. M.; Pavanelli, Carla S.; Graça, Weferson J.; Margarido, Vladimir P. (August 2018). "Morphologically Cryptic Species of the Astyanax bimaculatus "Caudal Peduncle Spot" Subgroup Diagnosed Through Cytogenetic Characters" (in en). Zebrafish 15 (4): 382–388. doi:10.1089/zeb.2018.1574. ISSN 1545-8547. PMID 29634423. http://www.liebertpub.com/doi/10.1089/zeb.2018.1574.
- ↑ Scharpf, Christopher; Lazara, Kenneth J. (29 December 2022). "Order CHARACIFORMES: Family CHARACIDAE: Subfamily STETHAPRIONINAE (a-g)". https://etyfish.org/characiformes4/.
- ↑ "Astyanax bimaculatus". Integrated Taxonomic Information System. https://www.itis.gov/servlet/SingleRpt/SingleRpt?search_topic=TSN&search_value=162854.
- ↑ Cockerell, Theodore D. A. (1915). "Scales of Panama fishes". Proceedings of the Biological Society of Washington 28: 155. https://www.biodiversitylibrary.org/page/3338632. Retrieved 30 May 2023.
- ↑ De Lucena, Carlos Alberto S.; Soares, Helena Gouvea (2016-12-31). "Astyanax abramis Jenyns 1842". Zootaxa. doi:10.5281/ZENODO.5618674. https://zenodo.org/record/5618674.
- ↑ Schmitter-Soto, Juan J. (2017-06-26). "A revision of Astyanax (Characiformes: Characidae) in Central and North America, with the description of nine new species" (in en). Journal of Natural History 51 (23–24): 1331–1424. doi:10.1080/00222933.2017.1324050. ISSN 0022-2933. https://www.tandfonline.com/doi/full/10.1080/00222933.2017.1324050.
- ↑ Pamponet, Vanessa de Carvalho Cayres; Carneiro, Paulo Luiz Souza; Affonso, Paulo Roberto Antunes de Mello; Miranda, Viviam Souto; Silva Júnior, Juvenal Cordeiro; Oliveira, Claudine Gonçalves de; Gaiotto, Fernanda Amato (December 2008). "A multi-approach analysis of the genetic diversity in populations of Astyanax aff. bimaculatus Linnaeus, 1758 (Teleostei: Characidae) from Northeastern Brazil". Neotropical Ichthyology 6 (4): 621–630. doi:10.1590/S1679-62252008000400010. ISSN 1679-6225. http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1679-62252008000400010&lng=en&tlng=en.
- ↑ Eigenmann, Carl H. (July 1907). "On further collections of fishes from Paraguay". Annals of the Carnegie Museum 4 (2): 110–157. doi:10.5962/p.264300. ISSN 0097-4463. https://www.biodiversitylibrary.org/part/264300.
- ↑ 24.0 24.1 24.2 Beebe, William (1945-09-14). "Vertebrate fauna of a tropical dry season mud-hole". Zoologica 30 (8): 81–88. doi:10.5962/p.210845. ISSN 0044-507X. https://www.biodiversitylibrary.org/part/210845.
- ↑ Rossini, Bruno César; Oliveira, Carlos Alexandre Miranda; Melo, Filipe Augusto Gonçalves de; Bertaco, Vinicius de Araújo; Astarloa, Juan M. Díaz de; Rosso, Juan J.; Foresti, Fausto; Oliveira, Claudio (2016-12-19). Rétaux, Sylvie. ed. "Highlighting Astyanax Species Diversity through DNA Barcoding" (in en). PLOS ONE 11 (12): e0167203. doi:10.1371/journal.pone.0167203. ISSN 1932-6203. PMID 27992537. Bibcode: 2016PLoSO..1167203R.
- ↑ Deprá, I.C.; Gomes, V.N.; Deprá, G.C.; Oliveira, I.J.; Prioli, S.M.A.P.; Prioli, A.J. (2014). "Molecular study of Astyanax altiparanae (Osteichthyes, Characidae) as a probable species complex". Genetics and Molecular Research 13 (3): 6015–6026. doi:10.4238/2014.August.7.16. PMID 25117359. http://www.funpecrp.com.br/gmr/year2014/vol13-3/pdf/gmr5038.pdf.
- ↑ Trujillo Jiménez, Patricia; Sedeño Díaz, Jacinto Elias; Camargo, Julio A.; López López, Eugenia (2013-07-24). "Reproductive traits and population structure of <i>Astyanax aeneus</i> (Characiformes: Characidae) from a subtropical river in Mexico". Revista de Biología Tropical 61 (2): 769–786. doi:10.15517/rbt.v61i2.11221. ISSN 2215-2075. PMID 23885588. http://dx.doi.org/10.15517/rbt.v61i2.11221.
- ↑ Schönhofen Longoni, L.; Giora, J.; Bernhardt Fialho, C. (January 2018). "Development of secondary sexual characters and their relationship to ontogeny and seasonal reproductive period in Hyphessobrycon igneus (Ostariophysi: Characiformes): dimorphism, ontogeny and reproduction in hyphessobrycon igneus" (in en). Journal of Fish Biology 92 (1): 131–149. doi:10.1111/jfb.13499. PMID 29139128. https://onlinelibrary.wiley.com/doi/10.1111/jfb.13499.
- ↑ de Fatima Andrian, Izabel; Baleroni Rodrigues Silva, Heloísa; Peretti, Danielle (2008). "Dieta de Astyanax bimaculatus (Linnaeus, 1758) (Characiformes, Characidae), da área de influência do reservatório de Corumbá, Estado de Goiás, Brasil". Acta Scientiarum 23 (2): 435–440.
- ↑ 30.0 30.1 30.2 Lobón-Cerviá, Javier; Bennemann, Sirlei (2000-09-29). "Temporal trophic shifts and feeding diversity in two sympatric, neotropical, omnivorous fishes: Astyanax bimaculatus and Pimelodus maculatus in Rio Tibagi (Paraná, Southern Brazil)" (in en). Fundamental and Applied Limnology 149 (2): 285–306. doi:10.1127/archiv-hydrobiol/149/2000/285. ISSN 1863-9135. http://www.schweizerbart.de/papers/fal/detail/149/86026/Temporal_trophic_shifts_and_feeding_diversity_in_t?af=crossref.
- ↑ Leitão, Rafael P.; Caramaschi, Érica P.; Zuanon, Jansen (September 2007). "Following food clouds: feeding association between a minute loricariid and a characidiin species in an Atlantic Forest stream, Southeastern Brazil". Neotropical Ichthyology 5 (3): 307–310. doi:10.1590/S1679-62252007000300011. ISSN 1679-6225. http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1679-62252007000300011&lng=en&tlng=en.
- ↑ Pearse, A. S. (1920). The fishes of Lake Valencia, Venezuela, by A. S. Pearse.. Madison: [s.n.]. doi:10.5962/bhl.title.18320. http://www.biodiversitylibrary.org/bibliography/18320.
- ↑ Dagosta, Fernando C.P.; Pinna, Mário De (2019-06-13). "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): 1. doi:10.1206/0003-0090.431.1.1. ISSN 0003-0090. https://bioone.org/journals/bulletin-of-the-american-museum-of-natural-history/volume-2019/issue-431/0003-0090.431.1.1/The-Fishes-of-the-Amazon--Distribution-and-Biogeographical-Patterns/10.1206/0003-0090.431.1.1.full.
- ↑ Cunha, Marina S.; Fregonezi, Aline R.; Fava, Lucioni; Hilsdorf, Alexandre W. S.; Campos, Lucio A. O.; Dergam, Jorge A. (February 2019). "Phylogeography and Historical Biogeography of the Astyanax bimaculatus Species Complex (Teleostei: Characidae) in Coastal Southeastern South America" (in en). Zebrafish 16 (1): 115–127. doi:10.1089/zeb.2018.1668. ISSN 1545-8547. PMID 30457941. https://www.liebertpub.com/doi/10.1089/zeb.2018.1668.
- ↑ Kullander, Sven O. (1982). "Cichlid fishes from the La Plata basin. Part III. The Crenicichla lepidota species group (Teleostei: Cichlidae)". Revue suisse de Zoologie 89: 627–661. doi:10.5962/bhl.part.82465. ISSN 0035-418X. http://www.biodiversitylibrary.org/part/82465.
- ↑ Kullander, Sven O. (1976). "Apistogramma luelingi sp. nov., a new Cichlid Fish from Bolivia (Teleostei: Cichlidae)". Bonner zoologische Beiträge 27–28: 263. https://www.biodiversitylibrary.org/page/44714413. Retrieved 30 May 2023.
- ↑ Ostrowski de Núñez, M.; Arredondo, N.J.; Gil de Pertierra, A.A. (2017-03-22). "Adult Trematodes (Platyhelminthes) Of Freshwater Fishes From Argentina: A Checklist". Revue suisse de Zoologie 124. doi:10.5281/ZENODO.322669. https://zenodo.org/record/322669.
- ↑ Pearse, A. S. (1921). "Crustacea from Lake Valencia, Venezuela" (in en). Proceedings of the United States National Museum 59 (2381): 459–462. doi:10.5479/si.00963801.59-2381.459. https://repository.si.edu/handle/10088/15161.
- ↑ Antunes, Dhenes Ferreira; Anderson Fernandes Silva, Bruno; Yamada, Fabio Hideki (October 2022). "Effect of parasitism on the relative condition factor of Astyanax bimaculatus (Characiformes: Characidae) a freshwater fish from Caatinga domain, Brazil". International Journal of Aquatic Biology 10 (5). https://ij-aquaticbiology.com/index.php/ijab/article/view/1560. Retrieved 30 May 2023.
- ↑ Silva, Marcelo Francisco da; Sousa-Henrique, Dalila de Deus; Messias-Luz, Nirvana; Borralho, Larissa dos Santos; Oliveira, Jorge Diniz de; Sindeaux-Neto, José Ledamir; Matos, Edilson Rodrigues (December 2019). "Myxobolus sp. (Myxozoa; Myxosporea) causing asymptomatic parasitic gill disease in Astyanax aff. bimaculatus (Characiformes; Characidae) in the Tocantins river basin, amazon region, Brazil". Revista Brasileira de Parasitologia Veterinária 28 (4): 739–743. doi:10.1590/s1984-29612019041. ISSN 1984-2961. PMID 31390431. http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1984-29612019000400739&tlng=en.
- ↑ Pellucci Barreto, Bianca (1998). "Biologia reprodutiva do lambarí Astyanax bimaculatus (Pisces, Characidae) no rio do Carmo, bacia do rio Grande, São Paulo". BIOS 6 (6): 121–130.
- ↑ Cordeiro, Jhennifer Gomes; Rodrigues, Jeane; Rodrigues, Maira da Silva; Bertolini, Rafaela Manchin; Nóbrega, Rafael Henrique; Yasui, George Shigueki; Maximino, Caio; Siqueira-Silva, Diógenes Henrique de (February 2020). "Reproductive cycle of the tetra Astyanax bimaculatus (Characiformes: Characidae) collected in Amazonian streams" (in en). Zygote 28 (1): 37–44. doi:10.1017/S0967199419000601. ISSN 0967-1994. PMID 31603066. https://www.cambridge.org/core/product/identifier/S0967199419000601/type/journal_article.
- ↑ 43.0 43.1 Araújo, Francisco G.; Nascimento, Aparecida A.; Gomes, Iracema D.; Sales, Armando; de Oliveira, Beatriz A. Chagas (2019-10-30). "Gonadal development and reproductive period of the characin Astyanax aff. bimaculatus (Characiformes: Characidae) in a tropical reservoir in southeastern Brazil". Zoologia 36: 1–14. doi:10.3897/zoologia.36.e30610. ISSN 1984-4689. https://zoologia.pensoft.net/article/30610/.
- ↑ Rodrigues, Jeane; Rosa-Silva, Maria; Tercya, Hadda; Jesus, Paulo; Miranda, Saynara; Oliveira, Hingrid; Lima, Bianca; Santos, Ludmylla et al. (June 2023). "Oogenesis and in vitro reproduction of the twospot astyanax Astyanax bimaculatus (Linnaeus, 1758) exposed to conspecific alarm substance" (in en). Animal Reproduction Science 253: 107252. doi:10.1016/j.anireprosci.2023.107252. PMID 37209522. https://linkinghub.elsevier.com/retrieve/pii/S0378432023000660.
- ↑ Weber, André Alberto; Arantes, Fábio Pereira; Sato, Yoshimi; Rizzo, Elizete; Bazzoli, Nilo (May 2013). "Oocyte adhesiveness and embryonic development of Astyanax bimaculatus (Linnaeus, 1758) (Pisces: Characidae)" (in en). Zygote 21 (2): 198–202. doi:10.1017/S096719941200007X. ISSN 0967-1994. PMID 22717095. https://www.cambridge.org/core/product/identifier/S096719941200007X/type/journal_article.
- ↑ Marcon, Lucas; Freitas, Vivian Rocha; Bazzoli, Nilo; Rizzo, Elizete; Benjamin, Laércio dos Anjos (2019). "Growth hormone on ovarian morphology of lambaris (Astyanax bimaculatus) after induced spawning". Ciência Rural 49 (8). doi:10.1590/0103-8478cr20180478. ISSN 1678-4596. http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-84782019000800651&tlng=en.
- ↑ Bogoni, Juliano André; Armiliato, Neide; Araldi-Favassa, Celi Teresinha; Techio, Vânia Helena (April 2014). "Genotoxicity in Astyanax bimaculatus (Twospot Astyanax) Exposed to the Waters of Engano River (Brazil) as Determined by Micronucleus Tests in Erythrocytes" (in en). Archives of Environmental Contamination and Toxicology 66 (3): 441–449. doi:10.1007/s00244-013-9990-5. ISSN 0090-4341. PMID 24435477. http://link.springer.com/10.1007/s00244-013-9990-5.
- ↑ Batista, Maria Tereza Oliveira; Almeida, Marilia Elias de; Vani, Gannabathula Sree; Oliveira, Mariana Feijó de; Rodrigues, Edson; Suda, Cecilia Nahomi Kawagoe (2019-12-26). "Enzymes from kidney, gill and brain tissues of Astyanax bimaculatus (lambari) as biomarkers of environmental impact in the Una River basin". Ambiente e Agua 14 (7): 1. doi:10.4136/ambi-agua.2314. ISSN 1980-993X. http://www.ambi-agua.net/seer/index.php/ambi-agua/article/view/2204.
- ↑ Arcifa, Marlene Sofia; Northcote, Thomas Gordon; Froehlich, Otávio (May 1991). "Interactive ecology of two cohabiting characin fishes ( Astyanax fasciatus and Astyanax bimaculatus ) in an eutrophic Brazilian reservoir" (in en). Journal of Tropical Ecology 7 (2): 257–268. doi:10.1017/S0266467400005423. ISSN 0266-4674. https://www.cambridge.org/core/product/identifier/S0266467400005423/type/journal_article.
- ↑ Goulart, Vinícius D.L. R.; Young, Robert J. (August 2013). "Selfish behaviour as an antipredator response in schooling fish?" (in en). Animal Behaviour 86 (2): 443–450. doi:10.1016/j.anbehav.2013.05.041. https://linkinghub.elsevier.com/retrieve/pii/S0003347213002601.
- ↑ "Astyanax bimaculatus – Two Spot Astyanax — Seriously Fish". https://www.seriouslyfish.com/species/astyanax-bimaculatus/.
- ↑ "Keeping and breeding Astyanax bimaculatus" (in en-US). https://www.aquaticcommunity.com/tetrafish/astyanaxbimaculatus.php.
- ↑ Jatobá, A.; Moraes, A.V.; Steckert, L.D.; Jesus, G.F.A. (November 2017). "Selection of autochtone probiotic for Astyanax bimaculatus". Arquivo Brasileiro de Medicina Veterinária e Zootecnia 69 (6): 1645–1652. doi:10.1590/1678-4162-9158. ISSN 1678-4162. http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0102-09352017000601645&lng=en&tlng=en.
- ↑ de Moraes França Ferreira, Pollyanna; Martins, Maria Tatiana Soares; Caldas, Débora Werneck; Gomes, Juliana Rodrigues; de Oliveira, Jerusa Maria; Salaro, Ana Lucia; Rocha, Juliana Silva; Zuanon, Jener Alexandre Sampaio (June 2017). "Curcuma longa as additive in the diet for Astyanax aff. bimaculatus" (in en). Fish Physiology and Biochemistry 43 (3): 691–702. doi:10.1007/s10695-016-0325-0. ISSN 0920-1742. PMID 28083736. http://link.springer.com/10.1007/s10695-016-0325-0.
- ↑ Silva, Eduardo; Aldegunde, Manuel; Silva, Deivisson Ferreira; Lopes, Carlize; Bertoldi, Fabiano Cleber; Weber, Robilson Antônio (February 2020). "Assessment of induction and recovery times of anaesthesia in Astyanax bimaculatus using 2‐phenoxyethanol and the essential oils of Melaleuca alternifolia and Ocimum gratissimum" (in en). Aquaculture Research 51 (2): 577–583. doi:10.1111/are.14404. ISSN 1355-557X. https://onlinelibrary.wiley.com/doi/10.1111/are.14404.
- ↑ Santos, Alex Braz Iacone; Araújo, Francisco Gerson (January 2015). "Evidence of morphological differences between Astyanax bimaculatus (Actinopterygii: Characidae) from reaches above and below dams on a tropical river" (in en). Environmental Biology of Fishes 98 (1): 183–191. doi:10.1007/s10641-014-0248-5. ISSN 0378-1909. http://link.springer.com/10.1007/s10641-014-0248-5.
Wikidata ☰ Q6398503 entry
![]() | Original source: https://en.wikipedia.org/wiki/Astyanax bimaculatus.
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