Population structure of two Astyanax Baird &amp; Girard, 1854 (Teleostei, Characidae) species from upper Paraguaçu river

Santos, Alexandre Clístenes de Alcântara; Novaes, José Luís Costa

doi:10.1590/s1516-89132008000100013

Cited by 9 publications

(8 citation statements)

References 7 publications

(5 reference statements)

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…fasciatus allocates energy to intermittent reproduction, attaining reproductive success in environments that present specialist species and resources which are now limited because of a more advanced succession process in relation to Iraí reservoir. Our data corroborate the results obtained by Mazzoni et al (2005), Abilhoa & Agostinho (2007) and Santos & Novaes (2008), who also characterized long reproductive periods for other Astyanax species in natural environments containing specialist species.…”

Section: Discussionsupporting

confidence: 92%

See 1 more Smart Citation

Reproductive tactics used by the Lambari Astyanax aff. fasciatus in three water supply reservoirs in the same geographic region of the upper Iguaçu River

et al. 2010

View full text Add to dashboard Cite

The species Astyanax aff. fasciatus was investigated as regards differences in reproductive tactics in three reservoirs with different ages (Iraí, Piraquara and Passaúna) located in the same geographic region. The biological material was obtained through monthly collections carried out from july/2006 to june/2007. The average value of the gonadosomatic index (GSI) in Passaúna reservoir was significantly higher in relation to the values obtained in the other reservoirs. Spawning was total in Iraí reservoir and partial in the others. Allometric growth of the species was negative in Iraí reservoir and positive in the others. The highest condition factor value was estimated in Iraí reservoir, followed by Piraquara and Passaúna reservoirs, respectively. Females predominated in all of the reservoirs during the study period. The sex ratio per length class showed, for the three reservoirs, the predominance of males in the smaller length classes. These results verified that the species uses distinct reproductive tactics in the analyzed reservoirs and that these tactics seem to reflect the degree of stabilization of each environment.A espécie Astyanax aff. fasciatus foi investigada quanto a diferenças nas táticas reprodutivas em três reservatórios de diferentes idades (Iraí, Piraquara e Passaúna), localizados em uma mesma região geográfica. O material biológico foi obtido através de coletas mensais realizadas de julho/2006 a junho/2007. Evidenciou-se maior atividade reprodutiva nos períodos mais quentes do ano. O valor médio do IGS no reservatório do Passaúna apresentou-se significativamente maior em relação aos valores obtidos nos outros reservatórios. A desova foi caracterizada do tipo total no reservatório do Iraí e do tipo parcelada nos outros reservatórios. A espécie apresentou crescimento alométrico negativo no reservatório do Iraí e alométrico positivo nos reservatórios do Passaúna e Piraquara. O maior valor do fator de condição foi estimado no reservatório do Iraí, seguido pelos reservatórios do Piraquara e Passaúna, respectivamente. Durante o período de estudo as fêmeas predominaram sobre os machos em todos os reservatórios. A análise da proporção sexual por classe de comprimento evidenciou, para os três reservatórios, o predomínio de machos nas menores classes de comprimento. Através destes resultados constatou-se que a espécie utiliza táticas reprodutivas distintas para os reservatórios analisados e que estas táticas parecem refletir o grau de estabilização de cada ambiente.

show abstract

Section: Discussionsupporting

confidence: 92%

“…B in marginal lagoons of the upper Iguaçu River. Studies carried out by Abelha & Goulart (2008) and by Santos & Novaes (2008) for Astyanax altiparanae and Astyanax sp. B, respectively, recorded the prevalence of females (possibly a characteristic of the Astyanax group).…”

Section: Discussionmentioning

confidence: 99%

Reproductive tactics used by the Lambari Astyanax aff. fasciatus in three water supply reservoirs in the same geographic region of the upper Iguaçu River

et al. 2010

View full text Add to dashboard Cite

show abstract

“…The genus Astyanax is made up of smallsize species not exceeding 120mm in maximum length (Miller et al 2005). A. aeneus (size range 13-95mm) is a large-size species within this genus, like A. janeiroensis (25-115mm) (Mazzoni et al 2005), as opposed to smaller species from the Paraguaçu River, Brazil, with standard length ranges 13-42mm (Santos & Novaes 2008) and intermediate size species such as A. aurocaudatus from the Cauca River, Colombia (14-74mm) (Román-Valencia & Ruiz 2005).…”

Section: Discussionmentioning

confidence: 99%

“…Condition factor, K, reflects the physiological condition of fish and may be related, among other aspects, to food availability and individual size (Santos & Novaes 2008). The latter authors state that values in two Astyanax species were higher during the wet season, which may be related to a greater supply of allochthonous food during this period.…”

Section: Discussionmentioning

confidence: 99%

Reproductive traits and population structure of <i>Astyanax aeneus</i> (Characiformes: Characidae) from a subtropical river in Mexico

Trujillo-Jiménez

Sedeño‐Díaz²,

Camargo

et al. 2013

RBT

View full text Add to dashboard Cite

Rasgos reproductivos y estructura de la población de Astyanax aeneus (Characiformes: Characidae) de un río subtropical en México. Champotón River is an unknown area within the Mesoamerican hotspot in Southestern México. Reproductive traits and population structure of Astyanax aeneus were analyzed along an environmental gradient of the upper, middle and lower sections of the river, where diverse environmental factors were recorded. For this, nets were cast for 1h at each site and A. aeneus were collected from all sections with sweep nets (5 and 10m long by 5m deep, 0.03m mesh size) and a casting net (0.05m mesh size). At each study site and campaign, a total of 80 specimens (in average) were collected and were fixed in 10% formaldehyde for further analysis. Population structure by size was analyzed for each study site, based on the relative frequencies by standard length classes. The length-weight relationship was determined, and the identification of gonadal developmental stages, reproductive period, size at first sexual maturity, relative fecundity, sex ratio and somatic indexes (gonadosomatic, hepatosomatic and Fulton's condition factor) were also assessed. Seven size classes were found in the upper and middle sections, and nine downstream, with seasonal and spatial pattern in size-class frequency distribution. Size at first maturity was 45.7mm for females and 40.8mm for males. The maximum relative fecundity was recorded at the downstream site and was positively correlated with body weight and standard length. Sex ratio (1.8:1 males: females) differed significantly from expected values (1:1). Gonadosomatic index scores indicated that the reproductive period of this species in the Champotón River was from April to July, during the warm and wet season. Hepatosomatic index was negatively correlated with the Gonadosomatic index, evidencing transfer of energy from the liver towards gamete production. This strategy enabled A. aeneus to maintain robustness during the study period with tiny changes in condition factor. A. aeneus in the Champotón River, as opposed to South American river congeneric species of similar size, shows early sexual maturity, a short reproductive period with high gonadosomatic index values, and high fecundity, a trade-off for the short reproductive period. Spatio-temporal segregation was evident: breeders congregate downstream, while juveniles prefer the upper reaches. This pattern allows A. aenus to be successful in a river with high frequency of hurricanes. Rev. Biol. Trop. 61 (2): 769-786. Epub 2013 June 01.

show abstract

“…3. Divergence in these coefficients between undescribed species may supply relevant information for their future discrimination (SANTOS & NOVAES 2008). SANTOS et al (2004) indicated that the parameters of this relationship may differ not only between species but also between stocks of the same species, considering that the growth coefficient depends on genetic, nutritional and environmental differences (LE CREN 1951, BAGENAL & TESH 1978.…”

Section: Discussionmentioning

confidence: 99%

Species of the Hoplias aff malabaricus complex (Characiformes: Erythrinidae): An investigation of coexistence in a Neotropical floodplain

Hauser¹,

Benedito²

2012

Zoologia (Curitiba)

View full text Add to dashboard Cite

This study assessed the coexistence of three species of thraira present in the Upper Paraná River floodplain, using population structure as an investigation tool. The species were designated as: Hoplias sp. 1, introduced after the construction of the Itaipu reservoir, and Hoplias sp. 2 and Hoplias sp. 3, native species that have been identified as Hoplias aff. malabaricus. We tested the hypothesis that those species in fact differ from each other in respect of population abundance, sex ratio, relative frequency of adults and juveniles, length structure and weight-length relationship. Additionally, possible effects of the flood pulse on the first four of these parameters were investigated. Samples were collected quarterly from March 2006 to December 2007 from nine collection sites on the floodplain. Hoplias sp. 1 presented a greater balance of sex ratio and length structures over the seasons, as well as a higher allometric coefficient. The population attributes of Hoplias sp. 2 and Hoplias sp. 3 showed a high responsiveness to hydrological seasonality, indicating that these species exploit available resources in a conspicuous flood period with greater efficiency. These differences, beyond reflecting possible mechanisms that allow closely related species to coexist, indicate the importance of understanding the life strategies adopted by each species which, as part of a complex system, are considered key elements of the aquatic community structure in the region, providing important information for habitat management and biodiversity conservation

show abstract

Population structure of two Astyanax Baird & Girard, 1854 (Teleostei, Characidae) species from upper Paraguaçu river

Abstract: ABSTRACT

Cited by 9 publications

References 7 publications

Reproductive tactics used by the Lambari Astyanax aff. fasciatus in three water supply reservoirs in the same geographic region of the upper Iguaçu River

Reproductive tactics used by the Lambari Astyanax aff. fasciatus in three water supply reservoirs in the same geographic region of the upper Iguaçu River

Reproductive traits and population structure of <i>Astyanax aeneus</i> (Characiformes: Characidae) from a subtropical river in Mexico

Species of the Hoplias aff malabaricus complex (Characiformes: Erythrinidae): An investigation of coexistence in a Neotropical floodplain

Contact Info

Product

Resources

About