Pancreatic islets in Platyrrhini monkeys:Callithrix jacchus,Saimiri boliviensis,Aotus azarae,andCebus apella. A cytological and immunocytochemical study

A histochemical and immunocytochemical study was performed to describe the cellular localization of four hormones in pancreatic tissue of the Callithricidae and Cebidae families belonging to Platyrrhini monkeys. Insulin, somatostatin, glucagon, and gastrin immunoreactive cells were detected in the pancreatic islets at light microscope level. Beta cells (insulin positve) were distributed in a peripheral mantle or in irregular clusters in a polar region of the islet. Also little groups (small islets) from three to six beta cells distributed in the pancreatic stroma were observed in all the species. A constant feature was the presence of neuroinsular complexes. The alpha cell population was composed of orangeophiles or phloxinophile cells and presented an heterogeneous composition as the result of their granular type (difference in immunocytochemical affinity). Alpha 1 cells (somatostatin) were scattered between the other cells or in the periphery of the islets, while alpha 2 cells (glucagon) were distributed in three different ways: (1) occupying polar positions; (2) disseminated in small groups; or (3) arranged in cord-like disposition. One or two G cells (gastrin) were found in few islets. This work was supported by grants from the Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Estudio Histológico Comparado del Sistema de Glándulas Endócrinas (EHIGE) program. Postgraduated Fellow from CONICET Established Investigator and Director of EHIGE.     

Two new species of night monkeys,genus Aotus (Cebidae,platyrrhini): A preliminary report on Aotus taxonomy

The nine allopatric species of Aotus recognized represent two natural groups distinguished by karyotype, color, and pelage patterns. Correlated with these group characters are reported differences in serum proteins and degrees of susceptibility or immunity to experimental infection with malarial parasites. The primitive gray-neck species group of Aotus contains A. brumbacki (new species), A. lemurinus (with subspecies lemurinus and griseimembra), A. trivirgatus, and A. vociferans. The derived red-neck group contains A. nancymai (new species), A. miconax. A. infulatus, and A. azarae (with subspecies azarae and boliviensis). Only the two new species are described but a key to the species and subspecies gives the diagnostic characters of each. The gray-neck group occurs almost entirely north of the Amazon, the red-neck group almost entirely south. The distributional exceptions are enclave populations resulting from river bend cutoffs. Formation of an enclave population of A. nancymai is discussed and available information on the biology of this species is reported.     

Validation of a Dehydroepiandrosterone-Sulfate Assay in Three Platyrrhine Primates (Alouatta caraya,Aotus azarae infulatus,and Sapajus apella)

International Journal of Primatology - The hormone dehydroepiandrosterone (DHEA) and its sulfate ester (DHEAS) are the most abundant circulating steroids in human and some nonhuman primates, and...     

Intraspecific chromosome variation in Cebus apella (cebidae,platyrrhini): The chromosomes of the yellow breasted capuchin Cebus apella xanthosternos wied, 1820

Chromosome studies in six wild-caught specimens of Cebus apella xanthosternos showed a distinctive chromosome pair number 11 that made it possible to distinguish this subspecies from other Cebus apella. The characteristic chromosome pair had intercalar heterochromatin unlike the “standard” chromosome type of Cebus apella and other species of the same genus, in which this chromosome pair shows a large, terminal, heterochromatic block. A comparison at the chromosomal level between different Cebus apella populations suggests that chromosome 11 in Cebus apella xanthosternos is a derived chromosome that has probably become fixed in this subspecies, either by selection or by drift in a small isolated population.     

Intracardiac and aortic thrombi in capuchin monkeys (Cebus apella)

Massive intracardiac or aortic mural thrombi, probably of septic origin, occurred in six capuchin monkeys (Cebus apella) and accounted for 26% of all adult deaths in a breeding group over a 4-yr period. Previous experimental inoculations with herpes simplex type 2 virus may have contributed to the development of these fatal lesions.     

Extensive enlargement of the maxillary sinus in Alouatta caraya (mammalia, primates, cebidae): an allometric approach to skull pneumatization in Atelinae

In contrast to the paranasal sinuses of Old World monkeys and hominoids, little information is available about the paranasal sinuses of New World monkeys. Because this information is crucial in order to draw further conclusions about the evolution and biological role of skull pneumatization, this study investigates the morphology of the paranasal sinuses in adult black-and-gold howler monkeys (Alouatta caraya). Volumes of the paranasal sinuses were calculated using computer software (SURFdriver or Allegro) from serial coronal CT scans of 20 skulls of both sexes. Skull pneumatization in A. caraya is more complex than in other higher primates. In both sexes, the maxillary sinus (MS) is the only pneumatic cavity and enlarges regularly into neighboring bones such as the frontal bone and the basisphenoid. The resulting pansinus is often partitioned by several vertical septa. As in most external cranial dimensions, mean MS volume of A. caraya (male 4.08 cm(3); female 2.00 cm(3)) shows significant sexual dimorphism. Reduced major axis regression analysis between MS volume and different cranial dimensions for A. caraya (and for available data from other platyrrhines) suggests a distinct association for this group, with Alouatta having one of the largest pneumatic cavities. The combination of this unusual expansion of the MS of Alouatta and the occurrence of distinct septa within the sinus may be a consequence of the distinct skull architecture of Alouatta.     

Dermatoglyphic patterns and pattern intensities of the genus Cacajao (Cebidae,platyrrhini) with observations on interspecific and subspecific differentiation

Palmar and plantar dermatoglyphic pattern types, area and total pattern intensities (API and TPI), and pattern intensity (PI) profiles are presented for the South American genus Cacajao of the subfamily Pitheciinae. The data are based on prints from 41 bald-head uacaries (C. calvus), 9 white bald-head uacaries (C. c. calvus), and 15 black-head uacaries (C. melanocephalus). In each extremity, loops of differing orientation were the most frequent pattern type; whorls were dominant at palmar interdigital (I) area 3 in C. calvus and at both I3 and I4 in C. melanocephalus. Open fields characterized the palmar thenar and plantar proximal hypothenar, thenar, calcar, and I3 and I4. There was little evidence of significant sexual dimorphism as assessed from PI values. The genus displayed significant asymmetry at palmar I3 (P?0.001) and plantar distal hypothenar (P?0.004). There were significant group differences between C. calvus and C. c. calvus in the palmar thenar API and plantar TPIs. The combined bald-head sample of C. calvus and C. c. calvus differed from C. melanocephalus in API of palmar I4 and plantar distal thenar, I2, and distal hypothenar (marginally), and in plantar TPIs. In PI profiles, C. melanocephalus departed from the pattern shared by C. calvus and C. c. calvus in both palmar and plantar interdigital areas. As a genus, the uacaries have markedly low plantar TPI values relative to palmar values (palm-sole index > 195). Of eight comparison cebid genera, only Chiropotes, another pitheciine genus, approximated these values.     

Hematological and plasma biochemical values for captive tufted capuchin monkeys (Cebus apella)

Hematological and blood biochemical parameters are of great importance in medical and veterinary practice. Unfortunately, normal reference range intervals for hematological and serum biochemical values in the tufted capuchin monkey (Cebus apella) have seldom been reported. The study reported here is based on data from blood samples collected from 44 monkeys over an 8-year period. Male and female data are displayed separately within two age categories: juveniles and adults, and effects for sex and age are examined. Significant differences between males and females are found for erythrocytes, hemoglobin, hematocrit, and α(1) globulin. Significant differences between juveniles and adults are found for neutrophils, calcium, aspartate aminotransferase (AST), alanine aminotransferase (ALT), alkaline phosphatase, inorganic phosphorus, glucose, total protein, serum iron, and some serum protein parameters and albumin/globulin ratio. These values are compared with values we previously reported, and their importance in care and well-being of captive tufted capuchin monkeys is discussed.     

Taxonomy of squirrel monkeys genus Saimiri (Cebidae,platyrrhini): A preliminary report with description of a hitherto unnamed form

Two groups of squirrel monkeys, genus Saimiri, are distinguished by external characters. The first, or Roman type, contains Saimiri boliviensis of upper Amazonia south of the Rio Marañón-Amazonas, with two subspecies of which S. boliviensis peruviensis is described as new. The second group, or Gothic type, contains three species: Saimiri sciureus with four subspecies distributed over much of tropical South America, Saimiri ustus of Brazil between the south bank Amazonian Rios Purús and Xingu, and S. oerstedi isolated on a Pacific coastal area straddling Costa Rica and Panamá. The geographic range of S. sciureus overlaps parts of those of S. ustus and S. boliviensis. Incomplete karyotypic data indicate that the diploid number of chromosomes for the genus is 44. Geographic variation is characterized by reduction from seven to six or five paired acrocentric autosomes through pericentric inversion with reciprocal increase in number of paired submetacentric or subtelocentric autosomes. Geographic distribution, behavior, sexual dimorphism including dichromatism, and hybridization are discussed. Ventral guide hairs for orientation of subprecocial newborn toward the maternal mammae are described. Distinguishing characters of species and subspecies are provided in a key. The taxons are listed with the taxonomy of each discussed, their geographic distribution plotted and mapped.     

Milk composition of captive tufted capuchins (Cebus apella)

Little is known about the milk composition of nonhuman primates, and it has never been examined in capuchin monkeys (genus Cebus). This article reports on the macronutrient milk composition (fat, crude protein (CP), lactose, dry matter (DM), and total gross energy (GE)) of captive housed tufted capuchins (Cebus apella) (n=8). C. apella milk averaged 5.22% fat, 2.40% CP, 6.94% lactose, 16.48% DM, and 0.89 kcal/g. Fat was the most variable macronutrient and was significantly higher in samples collected after 2 months of lactation. To explore the adaptive significance of C. apella milk composition, results were compared with data on milk composition from a closely related cebid, Saimiri boliviensis boliviensis, and another large‐brained anthropoid, Homo sapiens. C. apella milk was only significantly different from Saimiri milk in CP and the proportion of energy from CP. Compared with human milk, C. apella milk was lower in lactose but higher in fat, CP, DM, GE, and the proportion of energy from CP. Results from this small dataset suggest that among anthropoid primates, the macronutrient composition of milk is influenced by phylogeny, may vary relative to infant growth rates, but may not be related in any direct way to relative brain size. Am. J. Primatol. 72:81–86, 2010. © 2009 Wiley‐Liss, Inc.     

Taxonomy of squirrel monkeys genus Saimiri (cebidae,platyrrhini): A preliminary report with description of a hitherto unnamed form

Two groups of squirrel monkeys, genus Saimiri, are distinguished by external characters. The first, or Roman type, contains Saimiri boliviensis of upper Amazonia south of the Rio Marañón-Amazonas, with two subspecies of which S. boliviensis peruviensis is described as new. The second group, or Gothic type, contains three species: Saimiri sciureus with four subspecies distributed over much of tropical South America, Saimiri ustus of Brazil between the south bank Amazonian Rios Purús and Xingu, and S. oerstedi isolated on a Pacific coastal area straddling Costa Rica and Panamá. The geographic range of S. sciureus overlaps parts of those of S. ustus and S. boliviensis. Incomplete karyotypic data indicate that the diploid number of chromosomes for the genus is 44. Geographic variation is characterized by reduction from seven to six or five paired acrocentric autosomes through pericentric inversion with reciprocal increase in number of paired submetacentric or subtelocentric autosomes. Geographic distribution, behavior, sexual dimorphism including dichromatism, and hybridization are discussed. Ventral guide hairs for orientation of subprecocial newborn toward the maternal mammae are described. Distinguishing characters of species and subspecies are provided in a key. The taxons are listed with the taxonomy of each discussed, their geographic distribution plotted and mapped.     

Interactions between parents and infants,and infants-father separation in the common marmoset (Callithrix jacchus)

The New World monkey,Callithrix jacchus, diversely from most Old World primates, shares infant care among all family members. This paper intends to describe a pattern of infant care in the common marmoset, and to verify if the infant-father separation induces a depression reaction, such as found in other separation studies. In Experiment 1, 11 families (mother, father, and twin newborn infants) ofCallithrix jacchus were observed from 1st to 36th days of infants' life. It was noted that infants were carried most of the time in the beginning of life, and that from the 4th day on this care came mostly from the father. In Experiment 2, nine families were divided in three separation groups (15, 30, and 45 days of infants' life). Each group had a control and two experimental families. Removal of the father was done for three days, beginning at the indicated infants' ages. Results showed that upon removal of the father, the mother assumes the infants' care, and no depression reaction appeared.     

Quantification of hair cortisol concentration in common marmosets (Callithrix jacchus) and tufted capuchins (Cebus apella)

Quantifying cortisol concentration in hair is a non‐invasive biomarker of long‐term hypothalamic‐pituitary‐adrenal (HPA) activation, and thus can provide important information on laboratory animal health. Marmosets (Callithrix jacchus) and capuchins (Cebus apella) are New World primates increasingly used in biomedical and neuroscience research, yet published hair cortisol concentrations for these species are limited. Review of the existing published hair cortisol values from marmosets reveals highly discrepant values and the use of variable techniques for hair collection, processing, and cortisol extraction. In this investigation we utilized a well‐established, standardized protocol to extract and quantify cortisol from marmoset (n = 12) and capuchin (n = 4) hair. Shaved hair samples were collected from the upper thigh during scheduled exams and analyzed via methanol extraction and enzyme immunoassay. In marmosets, hair cortisol concentration ranged from 2,710 to 6,267 pg/mg and averaged 4,070 ± 304 pg/mg. In capuchins, hair cortisol concentration ranged from 621 to 2,089 pg/mg and averaged 1,092 ± 338 pg/mg. Hair cortisol concentration was significantly different between marmosets and capuchins, with marmosets having higher concentrations than capuchins. The incorporation of hair cortisol analysis into research protocols provides a non‐invasive measure of HPA axis activity over time, which offers insight into animal health. Utilization of standard protocols across laboratories is essential to obtaining valid measurements and allowing for valuable future cross‐species comparisons.     

Grasping behavior in tufted capuchin monkeys (Cebus apella): grip types and manual laterality for picking up a small food item

This study investigates prehension in 20 tufted capuchins (Cebus apella) in a reaching task requiring individuals to grasp a small food item fixed to a tray. The aim was twofold: 1) to describe capuchins' grasping techniques in detail, focusing on digit movements and on different areas of contact between the grasping fingers; and 2) to assess the relationship between grip types and manual laterality in this species. Capuchins picked up small food items using a wide variety of grips. In particular, 16 precision grip variants and 4 power grip variants were identified. The most frequently used precision grip involved the distal lateral areas of the thumb and the index finger, while the most preferred kind of power grip involved the thumb and the palm, with the thumb being enclosed by the other fingers. Immature capuchins picked up small food items using power grips more often than precision grips, while adult individuals exhibited no significant preference for either grip type. The analysis performed on the time capuchins took to grasp the food and withdraw it from the tray hole revealed that 1) precision grips were as efficient as power grips; 2) for precision grips, the left hand was faster than the right hand; and 3) for power grips, both hands were equally quick. Hand preference analysis, based on the frequency for the use of either hand for grasping actions, revealed no significant hand bias at group level. Likewise, there was no significant relationship between grip type and hand preference.     

Locomotion of free-ranging golden lion tamarins (Leontopithecus rosalia) at the National Zoological Park

Locomotor behavior and substrate use of cage-reared golden lion tamarins (Leontopithecus rosalia), newly released and free-ranging on the grounds of the National Zoological Park, were studied to determine if locomotion changed following exposure to naturalistic conditions. The animals employed a predominantly quadrupedal locomotor profile, incorporating leaping and vertical climbing to a lesser degree. There was no clear evidence of a change in locomotion due to the high degree of variability in these behaviors. The locomotor repertoire of the free-ranging group differed from that of groups occupying unenriched but relatively large conventional enclosures, indicating that whereas locomotion is plastic with respect to environment, substrate characteristics influence locomotor behavior and may promote stereotypical behavior. However, due to anatomical constraints, the locomotor repertoire tended to be less variable than substrate use. Similar behaviors were used in moving through a variety of habitat features in spite of strong associations between specific locomotor styles and substrate classes. © 1994 Wiley-Liss, Inc.     

Genetic Variation of Mantled Howler Monkeys (Alouatta palliata) from Costa Rica1

We examined genetic diversity of howler monkeys (Alouatta palliata) from Costa Rica. Blood samples of howler monkeys were collected at various locations in Costa Rica, and electrophoresis of total plasma proteins yielded no variation. We also conducted starch gel electrophoresis of red cell isozymes and did not find variation for any of the 14 loci analyzed (i.e., ACP, ADA, CA2, EST, GPI, IDH, LDH‐1, LDH‐2, MDH, PGD, PGM‐1, PGM‐2, SOD, and TPI). These findings were compared with the levels of genetic variation for A. seniculus and A. belzebul from one Brazilian population. Four of the 14 isozymes (ADA, GPI, PGD, and SOD) showed more than one allele for these species. Both A. seniculus and A. belzebul from Brazil showed similar levels of genetic variation. The potential causes of the low genetic variation in A. palliata from Costa Rica are discussed.     

Population genetic studies of Alouatta caraya (Alouattinae, Primates): inferences on geographic distribution and ecology

Cytochrome b DNA sequence data (ca. 1,140 bp) of 44 Alouatta caraya, including 42 specimens from three localities of Brazil and two from Bolivia, were used for phylogenetic reconstructions and population studies. Seventeen haplotypes were identified, eight of which were present in more than one individual. Seven of these eight haplotypes were shared by individuals from a same locality and one by individuals from two localities. We found 26 variable sites along the entire gene, consisting of 18 transitions and eight transversions; most replacements occurring at the third codon position (65.39%) in contrast to first and second positions (26.92 and 7.69%, respectively). In the sample collected at Chapada dos Guimarães (Brazil), nucleotide and haplotype diversity estimates were π=0.002325 and h=0.8772, respectively. Maximum parsimony analysis grouped all haplotypes in two clades, separating Bolivian haplotypes from Brazilian haplotypes, the grouping of which did not show a straightforward correspondence with geographic distribution. Median‐joining and TCS network pointed to haplotypes 11 or 12 as the most likely ancestral ones. Mismatch distribution and the goodness‐of‐fit test (SSD estimate=0.0027; P=0.6999) indicated that the population from Chapada dos Guimarães experienced a demographic expansion, in agreement with the median‐joining star‐like pattern, although this finding could not be confirmed by Fu's F_s test. Am. J. Primatol. 69:1093–1104, 2007. © 2007 Wiley‐Liss, Inc.     

Taste areas of the plica sublingualis of Alouatta and Aotus (Primates,Platyrrhini)

A conspicuous accumulation of taste buds occurs in the rostral part of the plica sublingualis ("frenal lamella") of Alouatta and Aotus forming taste areas (area gustatoria) superficially situated in the oral mucous membrane. They are found in close vicinity to the orifices of the sublingual salivary glands, but are lacking in the aboral part of the plica sublingualis. They do not occur in all primate species studied. A taste area does not projects above the surface of the surrounding tissue like a papilla. The taste buds open not in crypts of furrows of the oral mucosa, but directly into the spatium sublinguale of the oral cavity proper. In the anterior part of the cavum oris proprium different kinds and very differentiated qualities of sensoral information are perceived (touch, olfaction, temperature). It is conceivable that the taste areas play an important role in perceiving fresh saliva, together with the other sensorial structures in this part of the mouth. This problem can be solved experimentally and by behavioral studies, In addition to its topographical relation to the tongue, the organon sublinguale of Callicebus is structurally very similar to the plica sublingualis of Aotus and Alouatta. Since a sublingua does not occur in New World monkeys, it can be concluded that this organ represents a plica sublingualis which became adherent to the undersurface of the tongue.     

Olfactory discrimination of urine odors from five species by tufted capuchin (Cebus apella)

Urine collected from New World monkeys (tufted capuchin, squirrel monkey, cotton-top tamarin) and Old World monkeys (rhesus macaque, Japanese macaque), was used as the odor stimuli. Two adult tufted capuchins were trained on a successive odor-discrimination task with two odors, 30 trials each, in one session per day. Responses to one of the two odors (S+) were reinforced by sweet water. The monkeys failed to discriminate between the urine from the two species of macaques but could discriminate among the urine from the three species of New World monkeys. Furthermore, similarity of urine odors was analyzed by multi-dimensional scaling (MDS) and a cluster analysis. These analysis suggested that the tufted capuchin can distinguish differences among New World monkeys but not between the macaques. The natural distribution of the tufted capuchin overlaps with that of other New World monkeys, but it does not overlap with those of Old World monkeys. Consequently, it can be concluded that this difference in olfactory recognition in the tufted capuchin reflects their sympatric and allopatric relationships with other species.