Análise morfológica e morfométrica das gônadas de preguiça (Bradypus variegatus Schinz, 1825)

Barretto, M.L.M.; Amorim, Marleyne José Afonso Accioly Lins; Falcão, Marcus Vinícius de Castro

doi:10.1590/s0100-736x2013000900014

Cited by 2 publications

(5 citation statements)

References 9 publications

(12 reference statements)

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…In male giant anteaters, a notable feature is the intraabdominal position of the testes, a shared characteristic among all Xenarthrans. In anteaters ( Kaudern, 1914 ; Bartmann, Beyer & Wißdorf, 1991 ; Rossi et al, 2012 ) and sloths ( Grassé, 1955 ; Barretto, Amorim & Falcão, 2013 ), the testes are found caudomedially to the kidneys and joined to each other. In contrast, in armadillos, the testes occupy a more caudal and inguinal position, some authors mentioning the presence of a short peritoneal protrusion into the inguinal canal ( Rapp, 1852 ; Kaudern, 1914 ; Newfang, 1947 ).…”

Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

“…In contrast, Kleisner, Ivell & Flegr (2010) and Lovegrove (2014) suggest that abdominal testes represent the ancestral condition in (eutherian) mammals. However, the cited studies are either based on outdated phylogenetic data (Werdelin & Nilsonne, 1999) or assumptions concerning the location of testes in Xenarthrans that are either incorrect (testicular descent, Sharma et al, 2018) or imprecise, not considering the differences in the position of the testes in anteaters and sloths compared with armadillos (as described in: Kaudern, 1914;Rossi et al, 2012;Barretto, Amorim & Falcão, 2013). Some authors (Werdelin & Nilsonne, 1999;Rodrigues et al, 2008) suggest that the internal location of the testes in Xenarthrans is linked to their low body temperature (Aguilar & Superina, 2015: around 30 • C to 35 • C), which could ensure functional spermatogenesis despite the internal location of the gonads.…”

Section: Male Genital Organsmentioning

confidence: 99%

“…In females, only macroscopic characteristics of the genital organs have been mentioned so far ( Grassé, 1955 ; Schauerte & Osmann, 2012 ). There is a more detailed macroscopic and microscopic study on the reproductive morphology of the most closely related southern tamandua ( Tamandua tetradactyla ; Rossi et al, 2011 ; Rossi et al, 2012 ), and some literature on male and female armadillos ( Rapp, 1852 ; Owen, 1868 ; Newfang, 1947 ; Enders, 1960 ; Glover, 1963 ; Cardoso et al, 1985 ; Cetica, Aldana Marcos & Merani, 2005 ) and sloths ( Kaudern, 1914 ; Wislocki, 1928 ; Barretto, Amorim & Falcão, 2013 ; Favoretto et al, 2015 ). Some peculiar reproductive features have been portrayed in Xenarthrans, such as intraabdominal testes in males ( Kaudern, 1914 ; Rossi et al, 2012 ), a simple uterus, and absence of a cervix in female specimens ( Cetica, Aldana Marcos & Merani, 2005 ; Rossi et al, 2011 ), polyovular follicles in female armadillos of the family Chlamyphoridae ( Cetica, Aldana Marcos & Merani, 2005 ), and polyembryony with identical quadruplets in the nine-banded armadillo ( Dasypus novemcinctus ; McBee & Baker, 1982 ).…”

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Morphology of the genital organs of male and female giant anteaters (Myrmecophaga tridactyla)

Fromme

Yogui

Alves

et al. 2021

PeerJ

View full text Add to dashboard Cite

Background The giant anteater belongs to the supraorder Xenarthra which occupies a systematically isolated position among placental mammals. The species is categorized as Vulnerable by the International Union for Conservation of Nature, and understanding its reproductive characteristics is critical for future conservation efforts. Methods Gross and microscopic anatomy of the genital organs of 23 male and 21 female adult and young roadkill giant anteaters in Brazil were studied. Results Male giant anteaters presented a short conical penis, intraabdominal testes, and prostate, vesicular and bulbourethral glands. A tubular remnant of the partially fused Müllerian ducts extended from the seminal colliculus through the prostate gland, continued cranially in the genital fold, bifurcated, and attached with one elongation each to the left and right epididymal corpus. The structure presented a total length of up to 10 cm and contained a yellowish liquid in its lumen. Histologically, the caudal section of this structure resembled the female vagina, the middle portion corresponded to the uterus, and the extensions showed characteristics of uterine tubes. In adult female giant anteaters, ovoid ovaries with occasional seminiferous cord-like structures were observed. The animals possessed a simple uterus, which was directly continuous with the vaginal canal. The caudal portion of the vagina had two lumina, separated by a longitudinal septum and opening into two apertures into the vaginal vestibule, cranial to the urethral opening. In the urethral and the lateral vestibular wall, glandular structures with characteristics of male prostate and bulbourethral glands, respectively, were found. The vestibule opened through a vertical vulvar cleft to the exterior. A pair of well-differentiated Wolffian ducts with a central lumen originated ventrally at the vaginal opening into the vestibule and passed in a cranial direction through the ventral vaginal and uterine wall. Each duct extended highly coiled along the ipsilateral uterine tube until the lateral pole of the ovaries where it merged with the rete ovarii. Discussion The reproductive morphology of giant anteaters reveals characteristics shared with other Xenarthrans: intraabdominal testes, a simple uterus, and a double caudal vagina. The persistence of well-differentiated genital ducts of the opposite sex in both males and females, however, singles them out among other species. These structures are the results of an aberration during fetal sexual differentiation and possess secretory functions. The possibility of a pathological degeneration of these organs should be considered in reproductive medicine of the species. Conclusion Knowledge of the unique reproductive characteristics of the giant anteater is essential for future reproductive management of the species. Additionally, further research on the peculiarities of the persisting genital duct structures might help to understand sexual differentiation in placental mammals in general.

show abstract

Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

Section: Male Genital Organsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Morphology of the genital organs of male and female giant anteaters (Myrmecophaga tridactyla)

Fromme

Yogui

Alves

et al. 2021

PeerJ

View full text Add to dashboard Cite

show abstract

“…Quanto aos ramos cranial e caudal das veias renais, tanto direita quanto esquerda, nota-se que seguem o mesmo percurso e desembocam no respectivo ramo da veia cava caudal. Superior aos rins, estes ramos encontram-se e formam apenas uma veia cava caudal, a qual segue em direção ao átrio direito do coração, informação que confirma os achados para a própria espécie (Barretto et al, 2013).…”

Section: Discussionunclassified

Contribuição ao estudo da anatomia macroscópica dos rins e das estruturas vasculares sanguíneas no hilo renal do bicho-preguiça (Bradypus variegatus)

et al. 2019

View full text Add to dashboard Cite

Devido à ação antrópica sob o habitat natural do Bradypus variegatus, esta espécie encontra-se em risco de extinção. Um dos principais pontos para a conservação de espécies em extinção é conhecer sua anatomia e fisiologia. Porém, para o B. variegatus, com hábito exclusivamente herbívoro, onde se alimentam de folhas, flores, brotos, talos verdes e frutos, estas sendo sua principal fonte de ingestão hídrica, falta literatura sobre o funcionamento e aspectos anatômicos de seus rins. Logo, realizou-se um estudo da anatomia macroscópica dos rins e de suas estruturas vasculares, que atravessam o hilo renal. O objetivo é avaliar se sua estrutura possui diferenças anatômicas que justifiquem o baixo consumo de água. Oito pares de rins provenientes de bichos-preguiça adultos, pertencentes ao acervo do Departamento de Morfologia e Fisiologia Animal (DMFA) da UFRPE, foram utilizados para o estudo. Os rins foram retirados, dissecados, identificados e avaliados macroscopicamente. Os rins em B. variegatus apresentam forma elíptica, semelhante a um grão de feijão. Possui uma margem côncava e lisa, enquanto a outra é convexa, aonde se faz presente o hilo renal, com a presença das estruturas vasculares. Não foram observadas divisões em lobos, sendo classificado como órgão unilobado liso.

show abstract

Análise morfológica e morfométrica das gônadas de preguiça (Bradypus variegatus Schinz, 1825)

Cited by 2 publications

References 9 publications

Morphology of the genital organs of male and female giant anteaters (Myrmecophaga tridactyla)

Morphology of the genital organs of male and female giant anteaters (Myrmecophaga tridactyla)

Contribuição ao estudo da anatomia macroscópica dos rins e das estruturas vasculares sanguíneas no hilo renal do bicho-preguiça (Bradypus variegatus)

Contact Info

Product

Resources

About