Ita de Oliveira e Silva

Natural and Anthropogenic Hybridization in Two Species of Eastern Brazilian Marmosets (Callithrix jacchus and C. penicillata).

Animal hybridization is well documented, but evolutionary outcomes and conservation priorities often differ for natural and anthropogenic hybrids. Among primates, an order with many endangered species, the two contexts can be hard to disentangle from one another, which carries important conservation implications. Callithrix marmosets give us a unique glimpse of genetic hybridization effects under distinct natural and human-induced contexts. Here, we use a 44 autosomal microsatellite marker panel to examine genome-wide admixture levels and introgression at a natural C. jacchus and C. penicillata species border along the São Francisco River in NE Brazil and in an area of Rio de Janeiro state where humans introduced these species exotically. Additionally, we describe for the first time autosomal genetic diversity in wild C. penicillata and expand previous C. jacchus genetic data. We characterize admixture within the natural zone as bimodal where hybrid ancestry is biased toward one parental species or the other. We also show evidence that São Francisco River islands are gateways for bidirectional gene flow across the species border. In the anthropogenic zone, marmosets essentially form a hybrid swarm with intermediate levels of admixture, likely from the absence of strong physical barriers to interspecific breeding. Our data show that while hybridization can occur naturally, the presence of physical, even if leaky, barriers to hybridization is important for maintaining species genetic integrity. Thus, we suggest further study of hybridization under different contexts to set well informed conservation guidelines for hybrid populations that often fit somewhere between “natural” and “man-made.”

Hybridization effects and genetic diversity of the common and black-tufted marmoset (Callithrix jacchus and Callithrix penicillata) mitochondrial control region

Hybridization is continually documented in primates, but effects of natural and anthropogenic hybridization on biodiversity are still unclear and differentiating between these contexts remains challenging in regards to primate evolution and conservation. Here, we examine hybridization effects on the mitochondrial DNA (mtDNA) control region of Callithrix marmosets, which provide a unique glimpse into interspecific mating under distinct anthropogenic and natural conditions. DNA was sampled from 40 marmosets along a 50-km transect from a previously uncharacterized hybrid zone in NE Brazil between the ranges of Callithrix jacchus and Callithrix penicillata. DNA was also collected from 46 marmosets along a 30-km transect in a hybrid zone in Rio de Janeiro state, Brazil, where exotic marmosets appeared in the 1980s. Combining Callithrix DNA sampled inside and outside of these hybrid zones, phylogenetic and network analyses show C. jacchus and C. penicillata being parental species to sampled hybrids. We expand limited Callithrix population genetics work by describing mtDNA diversity and demographic history of these parental species. We show ancient population expansion in C. jacchus and historically constant population size in C. penicillata, with the latter being more genetically diverse than the former. The natural hybrid zone contained higher genetic diversity relative to the anthropogenic zone. While our data suggest hybrid swarm formation within the anthropogenic zone due to removed physical reproductive barriers, this pattern is not seen in the natural hybrid zone. These results suggest different genetic dynamics within natural and anthropogenic hybridization contexts that carry important implications for primate evolution and conservation.

Morphological Variation in Wild Marmosets ( Callithrix penicillata and C. geoffroyi ) and Their Hybrids

Evolutionary theory and observation predict wider phenotypic variation in hybrids than parental species. Emergent phenotypic novelty in hybrids may in turn drive new adaptations or speciation by breaking parental phenotypic constraints. Primate hybridization is often documented through genetic evidence, but knowledge about the primate hybrid phenotype remains limited due to a small number of available studies on hybrid primate morphology. Here, we examine pelage and morphometric variation in two Brazilian marmoset species (Callithrix penicillata and C. geoffroyi) and their hybrids. Hybrids were sampled in an anthropogenic hybrid zone in the municipality of Viçosa, Minas Gerais state, Brazil. We analyzed hybrid facial and body pelage color variation, and compared 13 morphometric measures between hybrids and parental species. Five different hybrid facial morphotypes were observed, varying from intermediate to parental-like. Hybrid facial morphotypes were biased towards C. penicillata, suggesting that the pelage of this species may be dominant to that of C. geoffroyi in this context, and indicating that mate preference, and therefore gene flow/introgression, may be biased towards C. penicillata within the hybrid zone. Hybrid morphometric features were on average intermediate to parental species traits, but transgressive hybrids were also observed, suggesting that morphometric variation for the studied traits is consistent with Rieseberg’s complementary allele model. Finally, we observed a decoupling of facial patterning and size/shape in hybrids, relative to parent phenotypes, suggesting that an important factor driving phenotypic novelty within the Viçosa marmoset hybrid zone might be the loosening of evolutionary constraints on phenotypic trait integration.

Comparison between tympanic and anal temperature with a clinical infrared ray thermometer in dogs

A clinical thermometer of infrared rays was used twice to record consecutively the temperature of the tympanic membrane in each ear and in the anus of 53 dogs. Temperatures did not differ significantly between organs, and were strongly correlated. The anal temperature measurement with an infrared thermometer in dogs is feasible and trustworthy, as well as the thermal checking of tympanic temperature.

Validation of qPCR Methods for the Detection of Mycobacterium in New World Animal Reservoirs

Zoonotic pathogens that cause leprosy (Mycobacterium leprae) and tuberculosis (Mycobacterium tuberculosis complex, MTBC) continue to impact modern human populations. Therefore, methods able to survey mycobacterial infection in potential animal hosts are necessary for proper evaluation of human exposure threats. Here we tested for mycobacterial-specific single- and multi-copy loci using qPCR. In a trial study in which armadillos were artificially infected with M. leprae, these techniques were specific and sensitive to pathogen detection, while more traditional ELISAs were only specific. These assays were then employed in a case study to detect M. leprae as well as MTBC in wild marmosets. All marmosets were negative for M. leprae DNA, but 14 were positive for the mycobacterial rpoB gene assay. Targeted capture and sequencing of rpoB and other MTBC genes validated the presence of mycobacterial DNA in these samples and revealed that qPCR is useful for identifying mycobacterial-infected animal hosts.

Vegetable exudates as food for Callithrix spp. (Callitrichidae): exploratory patterns.

Marmosets of the genus Callithrix are specialized in the consumption of tree exudates to obtain essential nutritional resource by boring holes into bark with teeth. However, marmoset preferences for particular tree species, location, type, and other suitable factors that aid in exudate acquisition need further research. In the current study, the intensity of exudate use from Anadenanthera peregrina var. peregrina trees by hybrid marmosets Callithrix spp. groups was studied in five forest fragments in Viçosa, in the state of Minas, Brazil. Thirty-nine A. peregrina var. peregrina trees were examined and 8,765 active and non-active holes were analyzed. The trunk of A. peregrina var. peregrina had a lower number of holes than the canopy: 11% were found on the trunk and 89% were found on the canopy. The upper canopy was the preferred area by Callithrix spp. for obtaining exudates. The intensity of tree exploitation by marmosets showed a moderate-to-weak correlation with diameter at breast height (DBH) and total tree height. The overall results indicate that Anadenanthera peregrina var. peregrina provides food resources for hybrid marmosets (Callithrix spp.) and these animals prefer to explore this resource on the apical parts of the plant, where the thickness, location, and age of the branches are the main features involved in the acquisition of exudates.

Feeding habits of marmosets: A case study of bark anatomy and chemical composition of Anadenanthera peregrina gum.

Primates of the genus Callithrix often obtain exudates from plants of the family Fabaceae. This study characterizes the chemical composition of exudates, and the anatomy and hystochemistry of the secretory ducts in the bark of Anadenanthera peregrina (L.) Speg. var. peregrina (Fabaceae). Exudates from this tree species represent an important component of the diet of hybrid marmosets, Callithrix spp. (Primates: Cebidae). A. peregrina was selected as the focal study tree because it is the only gum tree species exploited by Callithrix groups present within five urban forest fragments in the municipality of Viçosa, Minas Gerais State, Brazil. Gum samples were obtained directly from gouges made by the marmosets, while bark samples were obtained from A. peregrina plants, whether or not they were damaged by the marmosets. Constitutive secretory ducts were present in the bark of ungouged A. peregrina, whereas, marmoset damage caused induced secretory duct formation and an increase in the size of these ducts. The gum produced in the gouges made by the marmosets and in ungouged plants reacted positively to tests for polysaccharides, pectin, mucilage, and proteins. The gum from the gouges exhibited high water (41.0%), carbohydrate (38.2%), protein (19.0%), and mineral (Ca 0.4% and K 0.3%) content. We argue that the relatively high calcium content of A. peregrina gum plays an important nutritional role in, balancing a diet that is otherwise rich in phosphorous and poor in calcium.

Urban Sloths: Public Knowledge, Opinions, and Interactions

Simple Summary Free-range sloths living in an urban environment are rare. In this study, opinions, attitudes, and interactions with a population of Bradypus variegatus were investigated through short, structured interviews and informal, opportunistic observations of people in the pubic square where the sloths live. A questionnaire was applied to people in the square where the sloths live. Opinions about population size differed greatly and younger people were concerned as to whether the square was an appropriate place for them. Some human-sloth interactions showed the consequences of a lack of biological knowledge. Sloths are strictly folivorous and are independent of human sources of food. Apparently, sloths are indifferent to humans. Despite the good intentions of people, there are many misconceptions about the behaviour and needs of sloths, which causes low wellbeing for the animals. These results demonstrate that actions in environmental education of the public could be beneficial for sloths. Abstract Free-range sloths living in an urban environment are rare. In this study, the opinions, attitudes, and interactions with a population of Bradypus variegatus were investigated through short, structured interviews of people in the pubic square where the sloths live, in addition to informal, opportunistic observations of human-sloth interactions. A questionnaire was applied to people in the square where the sloths reside, and informal, opportunistic observations of human-sloth interactions were made. 95% of respondents knew of the sloths’ existence in the square and 87.8% liked their presence. Opinions about population size differed greatly and younger people were concerned as to whether the square was an appropriate place for them. Some human-sloth interactions showed the consequences of a lack of biological knowledge. People initiated all sloth-human interactions. The fact that sloths are strictly folivorous has avoided interactions with humans and, consequently, mitigated any negative impacts of the human-animal interaction on their wellbeing. These results demonstrate that, while there is a harmonious relationship between people and sloths, actions in environmental education of the square’s public could be beneficial for the sloths.

Correction: Validation of qPCR Methods for the Detection of Mycobacterium in New World Animal Reservoirs

[This corrects the article DOI: 10.1371/journal.pntd.0004198.].

Occurrence of Ehrlichia canis in free-living primates of the genus Callithrix.

Bacteria of the genus Ehrlichia are Gram-negative and coccoid-shaped microorganisms that cause ehrlichiosis - a serious infectious disease that often leads to death. These bacteria present a strong zoonotic potential and primates may act as reservoir hosts. This study involved a molecular analysis to detect these microorganisms in blood samples collected from nineteen primates of the genus Callithrix living free in an Atlantic Forest fragment in the municipality of Viçosa, state of Minas Gerais, Brazil. One of the 19 primates was found to be infected with Ehrlichia canis. This finding points to a new wild host of E. canis with a strong potential for transmission to humans because of its increasing contact with people. This is the first report of Ehrlichia spp. in primate of the genus Callithrix.