scholarly journals Sexual dimorphism and sex identification in the South American culpeo fox, Pseudalopex culpaeus (Carnivora : Canidae)

2000 ◽  
Vol 27 (6) ◽  
pp. 669 ◽  
Author(s):  
Alejandro Travaini ◽  
Javier Juste ◽  
Andrés J. Novaro ◽  
Angel F. Capurro
Keyword(s):  
Sexual Dimorphism ◽  
South American ◽  
Correct Classification ◽  
Easy Method ◽  
Adult Age ◽  
Age Class ◽  
Skull Measurements ◽  
Discriminant Analyses ◽  
Pseudalopex Culpaeus ◽  
Discriminant Power

Sexual dimorphism is analysed in skulls of the culpeo fox, Pseudalopex culpaeus, through multivariate and univariate approaches. The species shows a moderate level of sexual dimorphism with most cranial variables being, on average, 5% larger in males. Equations are obtained for inferring the sex of skulls of juvenile, subadult and adult culpeo foxes. The equations are based on a reduced set of variables obtained from stepwise discriminant analyses by age class on skull measurements. The discriminant power of all functions is estimated on the basis of a jackknife reclassification procedure. Correct classification is higher than 85% for both sexes, and is similar to, or higher than, the values reported for other foxes. The use of the discriminant function pooling subadult and adult skulls is rec ommended because it shows a high percentage of correct classification without the necessity of ascribing a collected skull to the subadult or adult age class before sex estimation. The equations provide an easy method to estimate the sex ratio of wild populations of this furbearer species using the abundant carcasses discarded throughout north-western Patagonia as a result of the intense hunting of the species. The information on sex ratios will help in the study of population dynamics and when monitoring the harvest of culpeo foxes.

Sexual Dimorphism among the Kathmandu University Students Assessed by Anthropometric Studies

2018 ◽  
Vol 9 (05) ◽  
pp. 20469-20472
Author(s):  
Shakya R ◽  
Bhattacharya SC ◽  
Shrestha R
Keyword(s):  
Young Adults ◽  
Sexual Dimorphism ◽  
Young Adult ◽  
University Students ◽  
Plastic Surgery ◽  
Age Group ◽  
Adult Age ◽  
Clinically Normal ◽  
Crime Detection ◽  
Males And Females

Objectives: To observe the sexual dimorphism among the young adult age group ranging from 18-21 years, of Kathmandu University students by measuring craniofacial circumference and canthal distances. Rationale of the study: These data could be useful for establishing the craniofacial standards and adds an implementation on plastic surgery, crime detection as well as in the industrial field. Method: 300 clinically normal students of Kathmandu University aged between 18-21 years were examined for the study. Fronto-occipital circumference, outer and inner canthal distances were measured. All the parameters were compared between males and females. Result: The cranial circumference as well as the inner and outer canthal distance in males was found to be significantly higher as compared to the females. Conclusion: The results concluded that sexual dimorphism remarkably exists in young adults of Kathmandu University students.

scholarly journals Widespread Infection with Hemotropic Mycoplasmas in Free-Ranging Dogs and Wild Foxes Across Six Bioclimatic Regions of Chile

2021 ◽  
Vol 9 (5) ◽  
pp. 919
Author(s):  
Sophia Di Cataldo ◽  
Aitor Cevidanes ◽  
Claudia Ulloa-Contreras ◽  
Irene Sacristán ◽  
Diego Peñaloza-Madrid ◽  
...  
Keyword(s):  
Genetic Structure ◽  
Mixed Models ◽  
Rhipicephalus Sanguineus ◽  
Species Group ◽  
South American ◽  
Adult Age ◽  
Network Analyses ◽  
Male Sex ◽  
Free Ranging ◽  
Sequence Types

Blood samples of 626 rural dogs, 140 Andean foxes (Lycalopex culpaeus), and 83 South American grey foxes (L. griseus) from six bioregions of Chile spanning 3000 km were screened for Mycoplasma DNA by conventional PCR and sequencing. Risk factors of infection were inferred using Generalized Linear Mixed Models and genetic structure by network analyses. Overall, Mycoplasma haemocanis/Mycoplasma haemofelis (Mhc/Mhf) and Candidatus Mycoplasma haematoparvum (CMhp) observed prevalence was 23.8% and 12.8% in dogs, 20.1% and 7.2% in Andean foxes, and 26.5% and 8.4% in grey foxes, respectively. Both hemoplasmas were confirmed in all the bioregions, with higher prevalence in those where ticks from the Rhipicephalus sanguineus species group were absent. Candidatus M. haematominutum and a Mycoplasma sp. previously found in South American carnivores were detected in one fox each. Although the most prevalent Mhc/Mhf and CMhp sequence types were shared between dogs and foxes, network analysis revealed genetic structure of Mhc/Mhf between hosts in some regions. Male sex was associated with a higher risk of Mhc/Mhf and CMhp infection in dogs, and adult age with CMhp infection, suggesting that direct transmission is relevant. No risk factor was identified in foxes. Our study provides novel information about canine hemoplasmas with relevance in distribution, transmission routes, and cross-species transmission.

Sexual dimorphism and paleoecology in Teleoceras, a North American Miocene rhinoceros

Paleobiology ◽  
2000 ◽  
Vol 26 (4) ◽  
pp. 689-706 ◽  
Author(s):  
Alfred J. Mead
Keyword(s):  
Sexual Dimorphism ◽  
Behavioral Ecology ◽  
Age Classes ◽  
Cross Sectional ◽  
Femur Length ◽  
Mean Values ◽  
Adult Age ◽  
Rhinoceros Unicornis ◽  
Hippopotamus Amphibius ◽  
Herd Structure

Sexual dimorphism is documented in 35 articulated adult skeletons, 24 females, and 11 males, of the Miocene rhinoceros Teleoceras major from Ashfall Fossil Beds, Nebraska. Morphometric analysis of 51 cranial, mandibular, forelimb, and hindlimb characters reveals larger male mean values in 50 of the 51 measurements, of which 23 are significantly different (p ≤ 0.01). The most clearly dimorphic feature is the i2 diameter. The dimorphism evident in additional mandibular and cranial characters is conservative when compared with the dimorphism present in the fore- and hindlimbs. Non-overlapping male and female ranges are recorded for humerus length, radius length, radius proximal width, and femur length, with corresponding dimorphism ratios (DR = male ÷ female) of 1.11, 1.12, 1.11, and 1.10. Maximum male longbone lengths exceed minimum female lengths by an average of 24% (20–29%). Developmental maturity is apparently asynchronous in T. major, with fusion of longbone epiphyses delayed a minimum of two relative adult age classes in males. Significant sexual dimorphism is evident in the radius (DR = 1.34) and femur (DR = 1.19) cross-sectional areas. Estimates of body mass suggest a DR value between 1.13 and 1.23. The cranial, mandibular, and body-size dimorphism in T. major approaches that seen in the extant rhinoceroses Ceratotherium simum and Rhinoceros unicornis. However, the apparent herd structure and breeding-age sex ratio for the Ashfall herd suggests a behavioral ecology for T. major different from that of extant rhinoceroses. Teleoceras was likely a herding polygynous species ecologically more similar to extant Hippopotamus amphibius of Africa.

Differentiation Parameters of Ribera del Duero Wines from Other Spanish Denominations of Origin

2001 ◽  
Vol 7 (3) ◽  
pp. 237-244 ◽  
Author(s):  
S. Pérez-Magariño ◽  
M. L. Gonzlez-San Jos
Keyword(s):  
Phenolic Compounds ◽  
Geographic Origin ◽  
Correct Classification ◽  
Discriminating Power ◽  
Discriminant Analyses ◽  
Discriminant Models

Commercial wines (247 samples) from different Spanish Denomination of Origin (D.O.) and from three consecutive vintages were analyzed. Stepwise discriminant analyses (SDA) were applied to the differentiation and classification of young red and rose wines by geographic origin. Good discriminant models with a small number of variables were obtained. These models gave high percentages of correct classification and prediction for both red (84.6% and 76.7%) and rose wines (87.7% and 82.6%). The variables with greater discriminating power were the phenolic compounds and the chromatic parameters. The discriminant models obtained to differentiate wines from D.O. “Ribera del Duero” were adequate with percentages of classification and prediction around 98%. So, these wines have some characteristics that differentiate them from the wines from other D.O.

Parasites as biological tags of fish stocks: a meta-analysis of their discriminatory power

Parasitology ◽  
2013 ◽  
Vol 142 (1) ◽  
pp. 145-155 ◽  
Author(s):  
ROBERT POULIN ◽  
TSUKUSHI KAMIYA
Keyword(s):  
Marine Fish ◽  
Meta Analysis ◽  
Discriminatory Power ◽  
Correct Classification ◽  
Fish Stocks ◽  
Clear Cut ◽  
Stock Discrimination ◽  
High Discriminatory Power ◽  
Discriminant Analyses ◽  
Biological Tags

SUMMARYThe use of parasites as biological tags to discriminate among marine fish stocks has become a widely accepted method in fisheries management. Here, we first link this approach to its unstated ecological foundation, the decay in the similarity of the species composition of assemblages as a function of increasing distance between them, a phenomenon almost universal in nature. We explain how distance decay of similarity can influence the use of parasites as biological tags. Then, we perform a meta-analysis of 61 uses of parasites as tags of marine fish populations in multivariate discriminant analyses, obtained from 29 articles. Our main finding is that across all studies, the observed overall probability of correct classification of fish based on parasite data was about 71%. This corresponds to a two-fold improvement over the rate of correct classification expected by chance alone, and the average effect size (Zr = 0·463) computed from the original values was also indicative of a medium-to-large effect. However, none of the moderator variables included in the meta-analysis had a significant effect on the proportion of correct classification; these moderators included the total number of fish sampled, the number of parasite species used in the discriminant analysis, the number of localities from which fish were sampled, the minimum and maximum distance between any pair of sampling localities, etc. Therefore, there are no clear-cut situations in which the use of parasites as tags is more useful than others. Finally, we provide recommendations for the future usage of parasites as tags for stock discrimination, to ensure that future applications of the method achieve statistical rigour and a high discriminatory power.

scholarly journals Taxonomy, allometry, sexual dimorphism, and conservation of the trans-Andean water-snake Helicops danieli Amaral 1937 (Serpentes: Dipsadidae: Hydropsini).

2021 ◽  
Author(s):  
Nathalie Kaladinsky Citeli ◽  
Julia Klaczko ◽  
Anderson Kennedy Soares De-Lima ◽  
Mariana de-Carvalho ◽  
Pedro M.S. Nunes ◽  
...  
Keyword(s):  
Sexual Dimorphism ◽  
Intraspecific Variation ◽  
Conservation Status ◽  
Tail Length ◽  
South American ◽  
Color Changes ◽  
Morphological Aspects ◽  
Water Snake ◽  
Morphological Diagnosis ◽  
Water Snakes

The extensive lack of knowledge on the morphological aspects of South American water-snakes, includes a poor understanding of phenotypic parameters, intraspecific variation, and conservation of the trans-Andean Helicops species, Helicops danieli Amaral, 1937. For the first time, we provide a multidisciplinary view using key features (e.g., morphology and niche modeling) to improve the taxonomic recognition of this species, as well as describing ontogenetic color changes, allometry, sexual dimorphism, and the conservation status of this poorly studied snake. First, we emended the morphological diagnosis of H. danieli with 23 characters and detected that juvenile tail length is positively related to allometric growth, and that juveniles differ from adults through the presence of the white nuchal collar. Females are larger than males for snout-vent length, whereas males showed proportionally longer tails and smaller head length growth. Suitable areas for H. danieli are restricted to the trans-Andean regions from the Magdalena drainage to the Caribbean coast, which also showed high values of anthropic impacts. Our multidisciplinary approach provided new insights into this South American water snake’s morphology, intraspecific variation, and distribution.

scholarly journals Sexual dimorphism in the South American water snake Helicops polylepis (Serpentes: Dipsadidae)

2021 ◽  
Vol 20 (1) ◽  
pp. 15-25
Author(s):  
Isla Carol Marialva Camargo ◽  
Jackeline Cristina Palma Veras ◽  
Síria Ribeiro ◽  
Ricardo A. Kawashita-Ribeiro ◽  
Rafael de Fraga ◽  
...  
Keyword(s):  
Sexual Selection ◽  
Sexual Dimorphism ◽  
Prey Availability ◽  
Morphological Characters ◽  
Offspring Size ◽  
Female Size ◽  
South American ◽  
The South ◽  
Water Snake ◽  
Fecundity Selection

Sexual selection, fecundity selection and ecological divergence have been the main explanations proposed for the origin and maintenance of sexual dimorphism. In this study we provide evidence of sexual dimorphism in the South American aquatic snake Helicops polylepis, which is mainly determined by body and head sizes. Males have longer tails and more subcaudal scales, and females have larger body and head and more ventral scales. The sexual dimorphism observed in different morphological characters of H. polylepis occurs in other species of xenodontine snakes and is interpreted as a consequence of sexual selection pressures. Data on growth rates associated with prey availability and female size-related offspring size are necessary to refine our analyzes and test specific hypotheses about the ecological and evolutionary bases of sexual dimorphism in H. polylepis.

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