Morphological Variation of the Glans Penis of South American Octodontid and Abrocomid Rodents

González, Luis Carlos Contreras; Torres‐Mura, Juan C.; Spotorno, Ángel E.; Catzeflis, François

doi:10.2307/1382431

Cited by 27 publications

(33 citation statements)

References 10 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…We also observed a subtle concavity in the ventral region of the baculum as previously described by Contreras et al (1993) to Octodontidae rodents. Nevertheless, Reig et al (1966) described a clearly different baculum for C. minutus from Santo Antonio da Patrulha, south Brazil.…”

Section: Discussionsupporting

confidence: 85%

“…This genus has a huge cariotipic diversity, including species varying from 2n = 10 to 2n = 70, which reflects in a complex evolutionary history, with still conflicting phylogenetic relations among species (Vitullo et al, 1988;Lessa and Cook, 1998;Contreras and Bidau, 1999;Mascheretti et al, 2000;Giménez et al, 2002;Gavas andFreitas, 2003, 2004;Bidau, 2006). Although, some evidence suggests that increase in penis ornamentation and decrease in baculum size are related to solitary behaviour (Parag et al, 2006), studies in Ctenomys penis indicate intra-and inter-specific variations such as in the intromitent sac and even in the baculum (Altuna and Lessa, 1985;Lessa and Cook, 1989;Contreras et al, 1993).…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Penial morphology in three species of Brazilian Tuco-tucos, Ctenomys torquatus, C. minutus, and C. flamarioni (Rodentia: Ctenomyidae)

Rocha-Barbosa

et al. 2013

Braz. J. Biol.

View full text Add to dashboard Cite

The present study analyses the glans penis and baculum morphology of three Brazilian tuco-tucos, Ctenomys torquatus Lichtenstein, 1830, Ctenomys minutus Nehring, 1887 and Ctenomys flamarioni Travi, 1981, in order to identify possible variations and understand some more about this taxonomically complex group. We used fixed penis from 15 previously listed adult specimens. For a more detailed baculum analysis, the penis underwent dissection and diaphanisation, whereas to analyse the glans penis surface we used Scanning Electron Microscopy (SEM). Results showed striking differences in baculum morphology among the three species. While C. minutus have a particular V-shaped proximal baculum tip, C. flamarioni baculum is thin throughout the shaft with rounded proximal and distal tips. Ctenomys torquatus have a shorter and larger baculum, similar to what has previously been described for the species. Glans penis surface microstructure analyses also revealed inter-specific differences, with penial spines varying in shape, size and, especially density. Although C. torquatus has a relatively small penis, it has the largest penial spine density, which suggests a more complex penial ornamentation in this species.Keywords: Ctenomys, Glans penis, morphology, Baculum, scanning electron microscopy. Morfologia peniana de três espécies de tuco-tuco do Brasil -Ctenomys torquatus,C. minutus e C. flamarioni (Rodentia: Ctenomyidae) ResumoO presente estudo analisa a morfologia do glans penis e do baculum de três tuco-tucos do Brazil -Ctenomys torquatus Lichtenstein, 1830, Ctenomys minutus Nehring, 1887, e Ctenomys flamarioni Travi, 1981 -com a finalidade de identificar possíveis variações e elucidar mais sobre grupo taxonômico complexo. Foram usados pênis fixados de 15 indivíduos adultos das espécies listadas anteriormente. Para uma análise mais detalhada do baculum, o pênis foi submetido a dissecções e diafanização, enquanto que, para a análise da superfície do glans penis, foi usada a técnica de microscopia eletrônica de varredura (MEV). Os resultados exibiram significativas diferenças na morfologia do baculum entre as três espécies. Enquanto C. minutus apresenta um baculum com uma ponta em forma de V característica, o baculum de C. flamarioni é fino ao longo do osso, com as pontas proximal e distal arredondadas. Ctenomys torquatus apresenta um baculum mais curto e largo, similar ao descrito anteriormente para a espécie. Análises da microestrutura na superfície do glans penis revelaram diferenças interespecíficas, com os espinhos penianos variando em forma, tamanho e, especialmente, densidade. Apesar de C. torquatus ter um pênis relativamente pequeno, apresenta a maior densidade de espinhos penianos, o que sugere uma complexa ornamentação peniana nesta espécie.Palavras-chave: Ctenomys, Glans penis, morfologia, Baculum, microscopia eletrônica de varredura.

show abstract

Section: Discussionsupporting

confidence: 85%

Section: Introductionmentioning

confidence: 99%

Penial morphology in three species of Brazilian Tuco-tucos, Ctenomys torquatus, C. minutus, and C. flamarioni (Rodentia: Ctenomyidae)

Rocha-Barbosa

et al. 2013

Braz. J. Biol.

View full text Add to dashboard Cite

show abstract

“…1b and 3). This stasis is at odds with many other groups of mammals, including primates, rodents, and artiodactyls (30)(31)(32)(33)(34), in which male reproductive structures apparently evolve quite rapidly. It has been hypothesized elsewhere (27) that sexual selection on male genitalia might have led to rapid diversification in the morphology of male reproductive organs in elephant shrews.…”

Section: Implications Of Molecular Data For the Evolution Of Elephantmentioning

confidence: 99%

“…We are not aware of any reported cases in mammals with such significant changes in overall morphology that coincide with little or no change in male reproductive structure. In fact, quite to the contrary, the literature regarding the evolution of male reproductive structures is rich with suggestions of rapid change in the morphology of the glans penis independent of overall body morphology, encompassing a wide range of mammalian groups (30)(31)(32)(33)(34).…”

Section: Implications Of Molecular Data For the Evolution Of Elephantmentioning

confidence: 99%

The Sahara as a vicariant agent, and the role of Miocene climatic events, in the diversification of the mammalian order Macroscelidea (elephant shrews)

Douady

Catzeflis

Raman

et al. 2003

Proc. Natl. Acad. Sci. U.S.A.

146

129

View full text Add to dashboard Cite

Although the Sahara is a major geographical feature of the African continent, its role in the diversification of animal species is not well understood. We present here a molecular phylogeny for members of the endemic African mammalian order Macroscelidea (elephant shrews) with molecular-clock calculations; this molecular phylogeny provides convincing evidence that the genus Elephantulus is diphyletic. Elephantulus rozeti, the only elephant shrew species that resides north of the Sahara, is the sister group of a species from a different genus (Petrodromus tetradactylus), which resides just south of the Sahara. The split between these taxa coincided with major Miocene climatic events, which triggered the cooling and aridification of midlatitude continental regions, and a shift in the Sahara from a tropical to an arid environment. Thus, the North African distribution of E. rozeti is not the result of dispersion from an eastern species of the genus, but instead the result of a vicariant event involving the formation of the Sahara. The splitting events involved with most Elephantulus species in our analysis appear to coincide with these climatic events. This coincidence suggests that the environmental consequences associated with this period played an important role in the radiation of this order of mammals. The strongly supported phylogeny provides compelling evidence for a complex history of mosaic evolution, including pronounced bradytelic morphological evolution in some lineages, accelerated morphological evolution in others, and a remarkably slow rate of evolution of the male reproductive structure.

show abstract

“…The glans penis of hystricognath rodents shows a characteristic intromittent sac (sacculus urethralis) which displays internal structures that have been described in most caviomorphs (Pocock 1922, Spotorno 1979, Contreras et al 1993. Detailed studies of penial variation in Ctenomys have been made in only two Uruguayan species (Altuna and Lessa 1985).…”

Section: Introductionmentioning

confidence: 99%

Evolutionary relationships of Ctenomys (Rodentia: Octodontidae) from Argentina, based on penis morphology

Balbontı́n¹,

Reig²,

Moreno³

1996

Acta Theriol.

View full text Add to dashboard Cite

Morphological Variation of the Glans Penis of South American Octodontid and Abrocomid Rodents

Cited by 27 publications

References 10 publications

Penial morphology in three species of Brazilian Tuco-tucos, Ctenomys torquatus, C. minutus, and C. flamarioni (Rodentia: Ctenomyidae)

Penial morphology in three species of Brazilian Tuco-tucos, Ctenomys torquatus, C. minutus, and C. flamarioni (Rodentia: Ctenomyidae)

The Sahara as a vicariant agent, and the role of Miocene climatic events, in the diversification of the mammalian order Macroscelidea (elephant shrews)

Evolutionary relationships of Ctenomys (Rodentia: Octodontidae) from Argentina, based on penis morphology

Contact Info

Product

Resources

About