Using sperm morphometry and multivariate analysis to differentiate species of gray Mazama

Abstract

There is genetic evidence that the two species of Brazilian gray Mazama, Mazama gouazoubira and Mazama nemorivaga, belong to different genera. This study identified significant differences that separated them into distinct groups, based on characteristics of the spermatozoa and ejaculate of both species. The characteristics that most clearly differentiated between the species were ejaculate colour, white for M. gouazoubira and reddish for M. nemorivaga, and sperm head dimensions. Multivariate analysis of sperm head dimension and format data accurately discriminated three groups for species with total percentage of misclassified of 0.71. The individual analysis, by animal, and the multivariate analysis have also discriminated correctly all five animals (total percentage of misclassified of 13.95%), and the canonical plot has shown three different clusters: Cluster 1, including individuals of M. nemorivaga; Cluster 2, including two individuals of M. gouazoubira; and Cluster 3, including a single individual of M. gouazoubira. The results obtained in this work corroborate the hypothesis of the formation of new genera and species for gray Mazama. Moreover, the easily applied method described herein can be used as an auxiliary tool to identify sibling species of other taxonomic groups.

Characterization of seminal parameters, sperm morphometry, micromorphology, and ultrastructure in gray brocket deer (Mazama gouazoubira, Fischer, 1814)

“…Literature on semen analysis in gray brocket deer is scarce (Cursino & Duarte, 2016; Duarte & Garcia, 1995; Rola et al, 2012). Thus, this study advances current knowledge on certain aspects of the male reproductive biology of this species.…”

“…Therefore, eight samples ( n = 8 ejaculates) were collected in total at 2.5 to 8 month intervals. Before all procedures, all animals were sedated using 5 to 10 mg/kg ketamine hydrochloride (Cetamin, Syntec, Brazil) and 0.5 to 1.5 mg/kg xylazine hydrochloride (Xilazina 10%, Venco, Brazil), both of which were administrated IM (Cursino & Duarte, 2016; Duarte & Garcia, 1995).…”

“…Yet, few studies have investigated fresh semen characteristics, or sperm morphometrics in M. gouazoubira . Existing studies have assessed testicular biometry and histology (Costa et al, 2011), semen collection (Rola, Zanetti, & Duarte, 2012), sperm analysis (Barrozo, Toniollo, Duarte, Pinho, & Oliveira, 2001; Cursino & Duarte, 2016) and artificial insemination techniques (Duarte & Garcia, 1995). Sperm morphometry has only been described to differentiate from other Mazama sp.…”

Natural Habitat, Housing, and Restraint of Six Selected Neotropical Animals in Trinidad and Tobago with the Potential for Domestication

“…Authors placed their weight against or on the animals as a form of restraint [124,125]. A number of different chemical restraint methods were implemented: Telazol ® at a dose rate of 4 mg/kg with 80 mg being the total dose given [114]; a combination of ketamine (dose rate of 5 mg/kg), xylazine (dose rate of 0.3 mg/kg), and midazolam (dose rate of 0.5 mg/kg) intravenously, with isoflurane for maintenance for M. gouazoubira [124]; ketamine hydrochloride at a dose [126]; ketamine (dose rate of 5 mg/kg), xylazine (dose rate of 0.3 mg/kg), and diazepam (dose rate of 1 mg/kg) used intravenously and maintained using isoflurane for M. gouazoubira [125]; a continuous infusion of ketamine chloride at a dose rate of 10 mg/kg intravenously and xylazine hydrochloride at 1 mg/kg intramuscularly [127]; and Zoletil 50 ®…”

Weak premating isolation between two parapatric brocket deer species

“…Evolutionary divergence time between both species was estimated as high as 5 Mya (Duarte et al, 2008; see also Escobedo-Morales et al, 2016;Heckeberg et al, 2016). Their phenotypes are very similar, probably as a consequence of their evolutionary convergence during the adaptation to tropical forests in South America (Duarte et al, 2008), although they have developed neat differences in sperm features (Cursino and Duarte, 2016). Hybrids are not known in the wild but two of them were produced in captivity and proved to be viable until maturity but infertile (Martins, 2015).…”