Occurrence of intersexuality in " Lambaris" , Astyanax scabripinnis (Jenyns, 1842), small characids from the Brazilian streams

Sá, Maria de Fátima Pereira de; Fragoso-Moura, E. N.; Fenerich-Verani, Nelsy; Ferro, Dagmar Aparecida de Marco

doi:10.1590/s1516-89132008000200011

Cited by 8 publications

(4 citation statements)

References 32 publications

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“…Also, according to these authors, in gonochorists species it is difficult to determine whether or not intersexuality arises from insufficient treatment (dosage, duration, or timing) or because the particular species is unable to fully respond to exogenous hormone treatment. Sá et al (2008) observed intersexuality in wild species gonads of A. scabripinnis and although not proven, the authors suggested the possible action of toxic agents in the environment. The analysis of the A. altiparanae gonads showed the presence of oocytes at different development stages in the same gonad, confirming the asynchrony of this process for the species, as observed by Marcon (2008) for the A. bimaculatus species, and Drummond (1996), Miranda (1996), andPereira-Filho (2000) for other species of the genus Astyanax.…”

Section: Discussionmentioning

confidence: 86%

Effectiveness of estradiol valerate on sex reversion in Astyanax altiparanae (Characiformes, Characidae)

Fontanetti

Senhorini

et al. 2012

Braz. arch. biol. technol.

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The objective of this study was to evaluate the effectiveness of estradiol valerate in an attempt to feminize the male Astyanax altiparanae. One thousand newly-hatched larvae were randomly distributed in four incubators. During a period of 30 days, estradiol valerate was administered in different dosages (20, 40, and 80 mg/kg of diet); the control group did not receive hormone in the diet. After 161 days of hatching, biometry was performed on 50 fishes per treatment group, and the gonads were analyzed. The hormone treatments were effective in feminizing A. altiparanae, achieving 70-76% of the desired sex, while the control treatment had 44% females. The hormone did not affect the growth of fish

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Section: Discussionmentioning

confidence: 86%

Effectiveness of estradiol valerate on sex reversion in Astyanax altiparanae (Characiformes, Characidae)

Fontanetti

Senhorini

et al. 2012

Braz. arch. biol. technol.

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“…It was noticed as a time‐ and concentration‐response process that gradually proceeded from the appearance of few oocytes at the edges of the testis to the alteration of the entire histoarchitecture of the gonad, including not only the gametes but also the interstitial and duct cells, and probably eliciting an eventual reproductive disability for the adult male fish. The induction of intersex gonads by xenoestrogens has been well documented in different gonochoric European ( Rutilus rutilus , Gobio gobio , Platichthys flesus , Xiphias gladius ) and even South American ( Astyanax scabripinnis ) fish species . Within poeciliids, although some histological alterations were found after the exposure to EDCs , only intersex induction was previously reported in G. affinis , but exposed to the androgen 17β‐trenbolone .…”

Section: Discussionmentioning

confidence: 92%

Intersex and liver alterations induced by long‐term sublethal exposure to 17α‐ethinylestradiol in adult male Cnesterodon decemmaculatus (Pisces: Poeciliidae)

Young

López

Cristos

et al. 2016

Enviro Toxic and Chemistry

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The aim of the present study was to assess the responses of the gonopodium morphology and the gonadal and liver histology of adult male Cnesterodon decemmaculatus to sublethal long-term exposure concentrations of 17α-ethinylestradiol (EE2). Two experiments were conducted exposing the fish to waterborne concentrations of EE2 ranging from 20 ng/L to 200 ng/L for 8 wk, 12 wk, and 16 wk. Intersex gonads were observed after 8 wk and 16 wk in fish exposed to 200 ng EE2/L and 100 ng EE2/L, respectively. Oocytes' development from testis germ cells and replacement of the efferent duct periodic acid-Schiff-positive secretion surrounding spermatozeugmata by parenchymal tissue and duct structure alterations were the major observed changes in the gonads. In contrast, no response was observed in the gonopodium morphology. Liver histology was also altered, showing increasing steatosis, single-cell necrosis to generalized necrosis, and disruption of acinar organization from 100 ng EE2/L to 200 ng EE2/L. In summary, the present results showed that although EE2 was not able to alter the morphology of a developed gonopodium, it was capable of inducing development of testicular oocytes in adult male C. decemmaculatus at environmentally relevant concentrations. Thus, externally normal but intersex C. decemmaculatus males would be expected in the wastewater-receiving streams that the species inhabits. According to the literature, the present study would be the first indicating estrogen-induced intersex in adult male poeciliid. Environ Toxicol Chem 2017;36:1738-1745. © 2016 SETAC.

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“…Ver Michelson & Liu (2008) para definições e revisão da literatura. Uma situação registrada em riachos brasileiros é a de populações de uma espécie reconhecidamente bissexuada que apresenta intersexualidade, com células reprodutivas femininas nos testículos (Sá et al 2008). Sem amadurecimento posterior dessas células, o caso não é considerado hermafroditismo (Michelson & Liu 2008).…”

Section: Características Reprodutivas Geraisunclassified

“…Como causas possíveis, a literatura sugere contato com poluentes (e.g. industriais, agrícolas) ou efluentes urbanos contendo disruptores hormonais (Sá et al 2008), embora Lima (2021) (Nikolsky 1963). O padrão de fêmeas maiores que machos parece estar associado ao aumento da cavidade celômica.…”

Section: Características Reprodutivas Geraisunclassified

Reprodução De Peixes De Riacho: Estado Da Arte, Métodos E Perspectivas

Caramaschi

Brito

2021

Oecol. Aust.

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Stream fish reproduction is still poorly studied in natural environments, especially in the Neotropical region. In this chapter, we recollect some characteristics of fish reproduction and some questions to guide current research, as: Does sexual dimorphism occur in the species? Which is the mode of reproduction? When and where does the species reproduce? Which environmental factors trigger reproductive events? When does the reproductive life begin? Which is the fecundity? Most of these questions can be answered when we have many specimens available, captured at different periods of the year, measured, weighed and dissected following appropriate protocols. Obtained data represent life history traits that allow to categorize the species in reproductive styles related to parental care and to determine their accordance to models of reproductive strategy associated with the predictability of environmental conditions. We highlight some aspects to be considered in current and future field and lab procedures, such as the recognition of sexual dimorphisms, the importance of naturalistic observation and lab procedures. We draw attention to the advances in studies on reproductive modalities in fish groups well represented in streams, such as inseminating characiforms and viviparous cyprinodontiforms. Finally, we highlight gaps, urgencies, and current perspectives for studies on the reproduction of stream fish, with emphasis on the need for basic studies of species biology, on the importance for building theoretical references and for the conservation of stream habitats in all Brazilian biomes.

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Occurrence of intersexuality in " Lambaris" , Astyanax scabripinnis (Jenyns, 1842), small characids from the Brazilian streams

Abstract: During studies carried out with a small characid (Astyanax scabripinnis), from the Brazilian streams located in

Cited by 8 publications

References 32 publications

Effectiveness of estradiol valerate on sex reversion in Astyanax altiparanae (Characiformes, Characidae)

Effectiveness of estradiol valerate on sex reversion in Astyanax altiparanae (Characiformes, Characidae)

Intersex and liver alterations induced by long‐term sublethal exposure to 17α‐ethinylestradiol in adult male Cnesterodon decemmaculatus (Pisces: Poeciliidae)

Reprodução De Peixes De Riacho: Estado Da Arte, Métodos E Perspectivas

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