Spontaneous pathology of the common marmoset (Callithrix jacchus) and tamarins (Saguinus oedipus, Saguinus mystax)

Background  Marmosets and tamarins are increasingly used in research, but their pathology remains poorly defined compared with Old World primates.

Methods  Necropsy records of 129 marmosets and 52 tamarins were reviewed; none was used experimentally.

Results  The most common marmoset lesions were dehydration, emaciation, nephritis, colitis, and inanition. The most common tamarin lesions were dehydration, ascites, emaciation, and congestive heart failure. Colitis and heart disease were the most common cause of death in marmosets and tamarins, respectively. Immature marmoset and tamarin deaths often occurred within the first month of life. Immature marmosets usually died from inanition, stillbirth, and colitis; immature tamarins from atelectasis, stillbirth, heart failure, and colitis. Lymphoma was the most common neoplasm for both marmosets and tamarins.

Conclusion  The findings were similar to prior reports with differences in frequency and severity. We report the first case of endometriosis in a marmoset.     

Spontaneous zinc deficiency in marmosets, saguinus mystax.

Moustached marmosets, Saguinus mystax, developed alopecia, skin lesions and general debilitation approximately 6 months after being brought into our laboratory. These lesions resembled the signs of zinc deficiency in pigs, rats and squirrel monkeys. The marmosets were fed a commercial monkey diet containing 150 parts per million zinc and about 100 g of apples and oranges per week. The addition of 40 parts per million zinc to the drinking water brought about improvement in hair coat and skin condition.     

Reproduction of wild-caught tamarins (Saguinus mystax mystax) under laboratory conditions

The reproductive performance of tamarins (Saguinus mystax mystax) under laboratory conditions was evaluated. Fifteen of 20 male-female pairs were fertile and produced 30 live births during an observation period of 3.5 years. Twenty-six breeders (65%) and 12 offspring (40%) more than 3 years old were alive at the termination of the reporting period.     

Pathology of captive moustached tamarins (Saguinus mystax)

The pathology of 33 moustached tamarins (Saguinus mystax) previously used in hepatitis A and GB virus studies is reported. Chronic lesions in colon, heart, and kidney were common in the monkeys and appeared not to be due to the experimental exposures. Colitis cystica profunda (CCP), a disease that affects humans and is characterized by the presence of mucin-filled epithelial downgrowths and cysts in the colonic submucosa, was found in 24 of the 33 (72.7%) tamarins. Interstitial myocardial fibrosis was present in 22 (66.6%) animals, and various degrees of membranoproliferative glomerulonephritis occurred in 28 (84.8%) monkeys. In addition, 28 (84.8%) tamarins demonstrated diffuse hepatocellular vacuolation with mild lymphoplasmacytic infiltrates, possibly as a result of the experimental infections, and peliosis hepatis occurred in 7 (21.2%) animals. The etiology of CCP is unknown, and no reliable animal models are available because most cases in animals are reported only sporadically. Myocardial fibrosis in tamarins has not been reported previously, and all current animal models require experimental manipulation of the animal to mimic the human disease. The results from this study suggest that captive S. mystax has high incidence of spontaneous CCP, myocardial fibrosis, and membranoproliferative glomerulonephritis. This species may be a spontaneous animal model for pathogenesis and experimental therapy studies of the analogous human diseases.     

Karyotype of Saguinus labiatus labiatus (red-bellied marmosets)

The karyotype of Saguinus labiatus labiatus was determined by the Giemsa-banding technique on leukocytes cultured from 10 marmosets. The diploid chromosome number (2n = 46) was the same and the chromosome complement similar to other marmosets of genus Saguinus. Small karyotypic differences were found between S. l. labiatus and white-lipped marmosets (Saguinus fuscicollis) in the size of the X chromosome and in the banding pattern of one pair of metacentric chromosomes. A karyotypic variant was detected in 1 S. l. labiatus, characterized by a diploid chromosome number of 45 with balanced autosomal translocation involving two pairs of acrocentric chromosomes (T 16/19).     

Body weights in mixed species troops of Saguinus mystax mystax and Saguinus fuscicollis nigrifrons in Amazonian Peru

An investigation of body weights of members of mixed species troops of Saguinus mystax mystax and Saguinus fuscicollis nigrifrons was conducted at the Rio Blanco Research Station in northeastern Peru. A total of 107 adult and subadult tamarin monkeys were trapped, measured, and released. Data collected indicate that mean body weights for adult male and female moustached tamarins are 564 gm and 626 gm, respectively, whereas for adult saddle-back tamarins these values are 412 gm and 411 gm. Subadults weighed 11-27% less than adults. Body weights recorded in this study are significantly greater than those previously reported for tamarins of the same species and age living in other areas of Amazonian Peru. We hypothesize that, in the case of moustached and saddle-back tamarins, advantages associated with feeding and foraging in mixed species troops facilitate greater efficiency in resource monitoring and result in the maintenance of larger body weights.     

Troop-specific responses to long calls of isolated tamarins (Saguinus mystax)

Recently captured moustached tamarins (Saguinus mystax) were briefly separated from other members of their troop. Most separated animals emitted long calls that were, in general, similar in acoustic structure to those of sympatric tamarin species while retaining species distinctiveness. Individual differences also appeared in call structure. The long calls of a separated animal were responded to almost entirely by members of the animal's own troop rather than by other troops, and reciprocal calling occurred among troop members significantly more often than expected by chance. Although there was no evidence of troop-specific call structure or dialect, there were troop-specific responses to the calls of separated tamarins. This response implies the existence of a stable and integrated troop structure that allows troop members to learn and to respond to the individual specific features of each troop member's calls.     

Mortality causes of the moustached tamarin (Saguinus mystax) in captivity.

From January 1987 to November 1990, 125 adult Saguinus mystax died at the CRCP. Enteritis/colitis (26%), hypoglycemia/cachexia (19%), and parasitic enteritis (13%) were the most common causes of death. Less common were purulent peritonitis (9%), lobular pneumonia (8%), and hemorrhagic gastroenterocolitis (6%). These results confirm the high frequency of gastroenteric lesions reported in Callitrichidae in captivity.     

Proximate mechanisms of reproductive monopolization in male moustached tamarins (Saguinus mystax)

In moustached tamarin (Saguinus mystax) groups, the single breeding female mates polyandrously with most or all nonrelated adult males. Nonetheless, paternity is monopolized in many groups by a single male. No evidence for male endocrine suppression has been found in this species. The proximate mechanisms of monopolization thus remain poorly understood. The aim of this study was to investigate the possible impact of agonistic interactions and mate-guarding on the monopolization of paternity in male moustached tamarins. Furthermore, we evaluated the likely costs of these behaviors, and whether olfactory cues might be used for its timing. We used behavioral data on proximity, agonistic interactions, time budgets, and scent-marking behavior to answer these questions. While direct agonistic competition does not play a prominent role, fertile females were consorted in some periods by one male, the sire of the previous and next litter. Consorting was instigated nearly exclusively by the male. It probably occurred during the female's periods of highest fertility, and thus likely functions as mate-guarding. The timing of the consortship was probably guided by olfactory cues in the female's scent marks. While we did not obtain direct evidence for energy costs in terms of increased energy expenditure or decreased food intake, we found that consorting males are more conspicuous and therefore may be more vulnerable to predators.     

Paternity and kinship patterns in polyandrous moustached tamarins (Saguinus mystax)

We studied patterns of genetic relatedness and paternity in moustached tamarins, small Neotropical primates living in groups of 1–4 adult males and 1–4 adult females. Generally only one female per group breeds, mating with more than one male. Twin birth are the norm. In order to examine the genetic consequences of this mating pattern, DNA was extracted from fecal samples collected from two principal and six neighboring groups. DNA was characterized at twelve microsatellite loci (average: seven alleles/locus). We addressed the following questions: Do all adult males have mating access to the reproductive female of the group? How is paternity distributed across males in a group? Can polyandrous mating lead to multiple paternity? Are nonparental animals more closely related to the breeders than to the population mean? And, are mating partners unrelated? Breeding females mated with all nonrelated males. In at least one group the father of the older offspring did not sire the youngest infant although he was still resident in the group. We also found evidence for multiple paternity in a supposed twin pair. Yet, within each group the majority (67–100%) of infants had the same father, suggesting reproductive skew. Relatedness within groups was generally high (average R = 0.31), although both nonrelated males and females occurred, i.e., immigrations of both sexes are possible. Mating partners were never found to be related, hence inbreeding seems to be uncommon. The results suggest that while the social mating system is polyandry, paternity is often monopolized by a single male per group. Am J Phys Anthropol, 2005. © 2004 Wiley-Liss, Inc.     

Demographic parameters and events in wild moustached Tamarins (Saguinus mystax)

This paper examines demographic events in the context of population structure and genetic relationships in groups of wild moustached tamarins (Saguinus mystax). We used a combination of long-term behavioral observations and genetic data from a total of eight groups from a population in northeastern Peruvian Amazonia. The mean group size was 6.0 (range = 4-9), including 2.5 adult males and 1.8 adult females. Within-group relatedness was generally high (r = 0.3), and most nonbreeding individuals were either natal or closely related to the respective same-sex breeder. The mean annual persistence of adults in the groups was 70% and 68% for males and females, respectively, and the reproductive tenure of one breeding pair lasted for at least 6 years. Migrations predominantly occurred after stability-disrupting events such as the immigration of new individuals and/or the loss of breeding individuals, or when groups were rather large. Migrations of both breeding and nonbreeding males and females occurred. Our results show that the hypothesis of Ferrari and Lopes Ferrari [Folia Primatologica 52:132-147, 1989] that tamarins live in smaller and less stable groups with lower relatedness compared to marmosets does not generally hold true. In contrast, we found that tamarin groups can consist of predominantly related individuals, and are stable as well. It is also apparent that a single demographic event can produce a chain of subsequent complex demographic changes.     

The ecology of seed dispersal in two species of callitrichid primates (Saguinus mystax and Saguinus fuscicollis)

Data collected during a 12-month field investigation of mixed species troops of Saguinus mystax and Saguinus fuscicollis in the Amazon Basin of north-eastern Peru indicate that callitrichid primates play an important role in tropical forest seed dispersal. Moustached and saddle-back tamarins were observed to ingest seeds from a variety of tree and liana species and pass them unharmed. These seeds tended to be large and heavy, and passed through the tamarin digestive tract in one to three hours. Experimental plantings of defecated seeds yielded a germination success rate of 70%. The specific gravity of these seeds (weight/volume) was inversely correlated with passage time and apparently had an indirect influence on the distance that seeds were dispersed from the parent tree. In the case of three preferred fruiting species, Leonia glycycarpa, Pourouma sp., and Hippocrateaceae #283, the present distribution of adult trees closely resembled the pattern of the seed shadow created by Saguinus. Moustached and saddle-back tamarins appeared to be reliable and high-quality dispersal agents for a number of tree and liana species. In this role, they are likely to exert an important influence on the composition, distribution, and regeneration patterns of Amazonian rain forest.     

Composition and Proposed Nutritional Importance of Exudates Eaten by Saddleback (Saguinus fuscicollis) and Mustached (Saguinus mystax) Tamarins

I provide the first comprehensive data on the composition and mineral content of exudates eaten by saddleback (Saguinus fuscicollis) and mustached tamarins (S. mystax) and assess Garber's (1984; 1993) hypotheses on the potential nutritional importance of exudates in the diet of tamarins. In accordance with his initial findings, nutritional analyses show that the gums consumed are relatively high in calcium and may serve to balance a diet otherwise low in this mineral and high in phosphorus. However, the data on the seasonal variation in the amount consumed do not support the hypothesis that exudates are of particular nutritional importance during the later stages of gestation or lactation for saddleback or mustached tamarins.     

Behavioural observations on captive pairs of wild caught tamarins (Saguinus mystax)

Quantitative data are given on 12 categories of behaviour, including scent marking, allogrooming, huddling, and proximity for individual tamarins within 14 male, female pairs and the mated pair of one family group of four animlals. Time sample data were recorded at 30 sec intervals to a total of 260 hr. In addition, some data were collected from within time sample intervals. Individual and intergroup variation in behaviour was a main finding of the study. It was found, however, that females scent marked significantly more than males, at least on the basis of their total marking frequencies, that females tended to groom males more than vice versa, and that although the general proportions of activities were similar in two conditions of housing, their spatial distribution was different under the two conditions. There was very little overt aggression among the pairs.     

Tetrapeltalonema (t.) mystaxi sp. n. (Nematoda: Filarioidea) from Brazilian moustached marmosets, Saguinus m. mystax.

Tetrapetalonema (T.) mystaxi sp. n. is described from the subscapular connective tissues of Saguinus mystax. The parasite is placed in the subgenus Tetrapetalonema and most closely resembles Tetrapetalonema atelensis, from which it can be differentiated by its long esophagus, size and shape of the spicules, and the size and arrangement of nuclei in the tail of the microfilaria.