Semen parameters and electron microscope observations of spermatozoa of the red wolf, Canis rufus

Abstract

Semen parameters were evaluated on ejaculates of a captive population of red wolves (Canis rufus) sampled over two consecutive mating seasons. A total of 31 samples from 15 animals yielded mean sperm motility of 69.6 +/- 19.4%, mean sperm density of 131 +/- 124 x 10(6) ml-1, mean total number of spermatozoa of 470 +/- 465 x 10(6) and mean percentage morphologically abnormal spermatozoa of 35 +/- 11.8%. Restricting the data to animals sampled three times or more or limiting the samples to proven breeders resulted in statistically non-significant differences in these numbers (P < 0.05). When compared with data from other canines the seminal parameters of red wolves are at the lower extremes of the range. In particular the proportion of morphologically abnormal spermatozoa (35%) is approximately twice that seen in other canine species. Light microscopic analysis of abnormal forms revealed that almost half (45%) were bent defects, another 40% were secondary defects (coiled, detached and immature) and 15% were primary defects. Electron microscopy confirmed the presence of substantial numbers of morphologically abnormal forms including double-headed and double-flagellar cells, bent or kinked forms especially in the neck region, acrosomal abnormalities and bizarre spermatids. Approximately one-third of the samples also showed the presence of white blood cells, in some cases demonstrating sperm phagocytosis (spermophagy). These results are consistent with the concept of declining sperm parameters associated with restricted gene pools in numerically limited populations. However, alternative explanations are also explored.

Assessment of chosen semen characteristics of two colour morphs of the Arctic fox Alopex lagopus L.

“…High species diversity is associated with the diversity of ejaculate parameters. The parameters of ejaculates from the blue Arctic foxes obtained in our study correspond with data reported by other authors for different breeds of dogs (Klimowicz, Niżański, Savić, Zbyryt, & Dubiel, 2005;Silva, Cardoso, Uchoa, & Silva, 2003) and for the red wolf (Canis rufus; Lockyear, MacDonald, Waddell, & Goodrowe, 2016;Koehler, Platz, Waddell, Jones, & Behrns, 1998). In turn, sperm concentration in ejaculates from white Arctic foxes was comparable to that reported by Yang et al (2016) for silver foxes (Vulpes fulvus) -45.27 × 10 6 /ml.…”

Reproductive features of the eastern mole (Scalopus aquaticus) and star-nose mole (Condylura cristata)

“…However, a barbed perforatorium is present in other Insectívora, including hedgehogs (J. M. Bedford and O. B. Mock, unpublished), a golden mole (J. M. Bedford and R. T. F. Bernard, unpublished), as well as elephant shrews (Woodall, 1991) and some megabats (Rouse and Robson, 1986;Cummins et al, 1988). Finally, sections of dog spermatozoa often show the interrupted form of the perforatorium observed in the present study (J. M. Bedford, unpublished), and the study of Koehler et al (1998) indicates that this may also be true for wolf spermatozoa.…”

CARACTERIZAÇÃO MORFOMÉTRICA E MORFOLÓGICA DE CÉLULA ESPERMÁTICA DE CAPIVARA (Hydrochoerus hydrochaeris)

“…Outra classificação aceita atualmente pelo Colégio Brasileiro de Reprodução Animal, separa os defeitos espermáticos em defeitos de cabeça (inclusive os de acrossoma) e defeitos de cauda, sendo que esta se subdivide em defeitos de peça intermediária, defeitos de peça principal e outros defeitos associados à cauda (CBRA, 1998). KOEHLER et al (1998) avaliaram padrões espermáticos de Canis rufus e estabeleceram comparações qualitativas entre as alterações morfológicas observadas em microscopia óptica e em microscopia eletrônica de transmissão. Além disso observaram que as formas imaturas, a bicefalia e a cauda dobrada eram visíveis e correlacionadas positivamente nas duas avaliações.…”