Origem dos nervos do plexo braquial de sagui-de-tufos-brancos (Callithrix jacchus Linnaeus, 1758) / Origin of brachial plexus nerves for common marmoset (Callithrix jacchus Linnaeus, 1758)

O sagui-de-tufos-brancos (Callithrix jacchus) é um pequeno primata que habita florestas arbustivas da Caatinga e a Mata Atlântica do Nordeste brasileiro. Essa espécie de sagui é muito comum e de fácil adaptação ao cativeiro, aspecto que estimula a captura clandestina desses animais, os quais são vítimas de maus tratos que causam lesões. A falta de conhecimento da anatomia de saguis e outros animais silvestres dificulta a aplicação segura de procedimentos clínicos, cirúrgicos e terapêuticos. O plexo braquial tem sido descrito em algumas espécies animais, porém até o momento não existia descrição em saguis-de-tufos-brancos (Callithrix jacchus). Para estudar o plexo branquial desses animais foram dissecados dez cadáveres de saguis-de-tufos-brancos (Callithrix jacchus) adultos sendo cinco machos e cinco fêmeas. Em todos os animais o plexo braquial originou- se dos nervos espinhais C5, C6, C7, C8 e T1, com poucas variações na origem e nas contribuições dos nervos, em ambos os antímeros, formando três troncos: cranial (C5 e C6), médio (C7) e caudal (C8 e T1).(AU)

The common marmoset (Callithrix jacchus) is a small primate that inhabits shrub forests of the Caatinga and the Atlantic Forest in Brazilian Northeast. This species of marmoset is very common and easy to adaptation in captivity, aspect that encourages illegal capture of these animals that are victims of mistreatments, causing injuries. The lack of knowledge in anatomy in marmosets and other wildlife hinders the safe application of clinical, surgical and therapeutic procedures. The brachial plexus has been described in some species of animals, but so far, there is no description for common marmoset (Callithrix jacchus). To study the brachial plexus of these animals were dissected ten corpses of common marmosets (Callithrix jacchus) adults, being five males and five females. In all animals, the brachial plexus was originated from spinal nerves C5, C6, C7, C8 and T1, with few variations in origin and the contributions of the nerves in both antimeres, forming three trunks: the cranial (C5 and C6), medium (C7) and caudal (C8 and T1).(AU)

Translocation and radio-telemetry monitoring of pygmy marmoset, Cebuella pygmaea (Spix, 1823), in the Brazilian Amazon / Translocação e monitoramento por radiotelemetria do mico-leãozinho, Cebuella pygmaea (Spix, 1823), na Amazônia brasileira

Two groups of pygmy marmoset (Cebuella pygmaea) were rescued along the left bank of the Madeira River during the formation of Santo Antônio Hydroelectric Dam reservoir in the state of Rondônia, Northern Brazil. Reintroduction of both groups occurred in areas of open Tropical rainforest located within the project´s Permanent Preservation Area. A post-release monitoring was conducted for three months using radio-telemetry. Individuals of each group remained together and settled in stable home ranges near their respective release sites. The mortality rate of translocated animals was about 7%. This seems to be the first report documenting the complete group translocation of C. pygmaea and the first to successfully employ radio-telemetry techniques in monitoring this species. This study demonstrated the feasibility of translocation and the use of radio-telemetry in monitoring C. pygmaea.

Dois grupos de mico leãozinho (Cebuella pygmaea) foram resgatados ao longo da margem esquerda do Rio Madeira durante o enchimento do reservatório da Usina Hidrelétrica Santo Antônio, em Rondônia, norte do Brasil. A reintrodução de ambos os grupos deu-se em áreas de floresta ombrófila densa aberta dentro da Área de Preservação Permanente do empreendimento. Após a reintrodução, empregou-se a técnica de radiotelemetria para o monitoramento dos animais por aproximadamente três meses. Cada um dos grupos manteve-se coeso e estabeleceu suas áreas de vida em regiões próximas àquelas onde foram soltos. A taxa de mortalidade foi de aproximadamente 7%. Este parece ser o primeiro trabalho a documentar a translocação de grupos completos de C. pygmaea e o primeiro a empregar com sucesso a radiotelemetria no monitoramento desta espécie. Este estudo, portanto, demonstra a factibilidade da translocação e do uso da radio-telemetria para monitorar C. pygmaea.

Estudo endócrino reprodutivo e do comportamento sócio-sexual de sagui-de-tufo-preto (Callithrix penicillata) mantido em cativeiro / Reproductive endocrine and socio-sexual behavior study of black-tufted-marmoset (Callithrix penicillata) kept in captivity

A comunicação do estado reprodutivo nos primatas da família Callithrichidae, depende principalmente dos comportamentos sócio-sexuais como um sistema de sinalização primário, uma vez que nestas espécies a ovulação não é percebida pelos machos. Neste trabalho, os padrões de comportamentos sócio-sexuais foram analisados em conjunto com as concentrações de metabólitos fecais dos esteróides sexuais progesterona (MFP), estradiol (MFE) e testosterona (MFT) em casais cativos de Sagüi-de-tufos-pretos (Callithrix penicillata), nas diferentes fases do ciclo ovariano. O grupo estudado era composto por quarto casais adultos, mantidos no Centro de Reabilitação de Animais Selvagens da prefeitura de São Paulo. Os padrões comportamentais foram registrados pelo método de amostragem focal por intervalo de tempo a cada 30 segundos, cinco vezes por semana, totalizando 14.400 registros por animal. A mensuração das concentrações de metabólitos fecais dos esteroides sexuais foram realizados pelo método de enzima imunoensaio (EIE). Os resultados obtidos dessas concentrações possibilitaram a determinação endócrina das fases do ciclo ovariano (folicular e luteal) e de suas respectivas durações, assim como a determinação da fase periovulatória. Foram caracterizados 31 ciclos ovarianos completos, com duração de 24,3±4,1 dias (média ±DP), sendo que a fase folicular compreendeu 13,04±4,8dias e a fase lútea 11,2±4,2 dias. Os comportamentos sócio-sexuais (marcação por cheiro, cheirar genitália, catação e apresentação sexual) e a variável "proximidade" mostraram-se significativamente mais prevalentes na fase periovulatória do que nas demais fases do ciclo. Não houve alteração das concentrações de MFT dos machos ao longo de todo o período estudado. A análise conjunta das concentrações de metabólitos fecais de esteróides sexuais e dos comportamentos sócio-sexuais possibilitou um melhor entendimento das relações endócrino-comportamentais e reprodutivas de C. penicillata.

The communication of the female reproductive status in Callithrichidae relies mainly on the socio-sexual behavior, as generally the ovulation is concealed in this primate family by a primary signaling system. In this study the socio-sexual behavior patterns was analyzed in association with the concentration of fecal metabolites of sex steroid hormones progesterone (MFP), estradiol (MFE) and testosterone (MFT) in captive couples of Black-Tufted-Marmoset (Callithrix penicillata), during the different phases of the ovarian cycle. The studied group was composed of four adult couples kept in the São Paulo City Wild Animals Rehabilitation Center. The behavioral patterns were record by focal samplings, with 30 seconds intervals for each observation, five days a week, totalizing 14.400 registers per animal. The measurement of fecal metabolites of progesterone (MFP), estradiol (MFE) and testosterone (MFT) proceeded by enzyme immune assay (EIA). The results allowed to determine the duration of the ovarian cycle and to characterize three different phases (follicular, periovulatory and luteal). It was possible to determine 31 complete cycles that lasted 24.3±4.1 days (Mean ± SD). The follicular and luteal phases lasted 13.04±4.8 and the luteal phase 11.2±4.2 days. The behavioral patterns (scent marking, sniff genitals, grooming and sexual presentation) were more prevalent in the periovulatory phase as the behavioral variable "proximity" as well. There were no variations in the concentration of MFT in the males during the period studied. The associated analyses of the fecal metabolite of sex steroids and the socio-sexual behaviors led to a better understanding of the factors involved in the reproduction of C. penicillata.

Reporting social behaviours of mixed-species troops formed by Callithrix jacchus and Callithrix penicillata (Primate, Callitrichidae) / Comportamento social em grupos mistos de Callithrix jacchus e Callithrix penicillata (Primate, Callitrichidae)

In New World primates, mixed-species troops have been reported. Here, we analysed the performance of affiliative and agonistic behaviours of Callithrix jacchus and Callithrix penicillata living in mixed groups. For this purpose, we recorded the interaction of the individuals from two groups located in Bauru city, in the state of São Paulo (Brazil). Our data show that in both groups, affiliative behaviours appeared more frequently than agonistic ones. We concluded that there is cohesion inside the mixed-species troops observed. We suggest that a deeper knowledge about the social behaviour of mixed-species troop species certainly may be useful in projects linked with the management of the impact caused by them.

Grupos mistos em espécies de primatas do Novo Mundo têm sido relatados. Aqui, nós avaliamos a emissão de comportamentos afiliativos e agonísticos em grupos mistos formados por Callithrix jacchus e Callithrix penicillata. Para tanto, registramos a interação de dois grupos, localizados no município de Bauru, Estado de São Paulo (Brasil). Nossos dados mostram que nos dois grupos a emissão de comportamentos afiliativos foi maior do que a de comportamentos agonísticos, indicando que há coesão dentro dos grupos mistos estudados. Sugerimos que um conhecimento mais elaborado sobre o comportamento social de grupos mistos pode ser útil em projetos de impactos causados por espécies invasoras.

Polymeric nanoparticle formulation of Octapeptide (NP-OP): In vitro release and in vivo effect in common marmosets, Callithrix jacchus Linn.

yielded an average particle size of 120 nm with 70% encapsulation-efficiency. In vitro release profile of NP-OP showed sustained release of OP for 21 days. In vivo anti-fertility studies were conducted in marmosets. Results indicated that control animals conceived in the same cycle while two of three treated animals failed to conceive in treatment cycle. The in vivo studies thus corroborate with in vitro release of OP, demonstrating its anti-fertility activity in 66% of animals.

Contested dominance modifies the anovulatory consequences of social subordination in female marmosets

Dominance status among female marmosets is reflected in agonistic behavior and ovarian function. Socially dominant females receive submissive behavior from subordinates, while exhibiting normal ovulatory function. Subordinate females, however, receive agonistic behavior from dominants, while exhibiting reduced or absent ovulatory function. Such disparity in female fertility is not absolute, and groups with two breeding females have been described. The data reported here were obtained from 8 female-female pairs of captive female marmosets, each housed with a single unrelated male. Pairs were classified into two groups: "uncontested" dominance (UD) and "contested" dominance (CD), with 4 pairs each. Dominant females in UD pairs showed significantly higher frequencies (4.1) of agonism (piloerection, attack and chasing) than their subordinates (0.36), and agonistic behaviors were overall more frequently displayed by CD than by UD pairs. Subordinates in CD pairs exhibited more agonistic behavior (2.9) than subordinates in UD pairs (0.36), which displayed significantly more submissive (6.97) behaviors than their dominants (0.35). The data suggest that there is more than one kind of dominance relationship between female common marmosets. Assessment of progesterone levels showed that while subordinates in UD pairs appeared to be anovulatory, the degree of ovulatory disruption in subordinates of CD pairs was more varied and less complete. We suggest that such variation in female-female social dominance relationships and the associated variation in the degree and reliability of fertility suppression may explain variations of the reproductive condition of free-living groups of common marmosets.

Fecal androgen levels in common marmoset (Callithrix jacchus) males living in captive family groups

In captive common marmoset groups, the reproductive inhibition observed in subordinate female seems to be a result of olfactory, visual and behavioral cues from the dominant female. However, few studies have examined the relationship among adult males living in the same social group. These studies have shown that reproductive failure among peer males seems to be based on hormonal and behavioral mechanisms. New insights on sexual strategies in primates have been shown using fecal steroids, but so far no information is available for common marmoset males. In the present study, we evaluated the influence of light-dark cycle, age and reproductive condition on the profile of fecal androgens in males living in the same family group. Feces were collected from six fathers and six sons for androgen determination during the light phase of the 24-h cycle for eight days randomly distributed over a 4-week period. Androgen levels were determined by enzyme immunoassay technique. Adult sons showed higher androgen levels (166.97 ± 22.95 ng/g) than fathers (80.69 ± 44.38 ng/g) and juveniles (49.06 ± 23.15 ng/g; P < 0.05). No diurnal variation (P > 0.05) in fecal androgen profile was observed in adults or juveniles. No indication of androgen-mediated social competition between fathers and adult sons was demonstrable. These results provide basic information on fecal androgen profile useful to investigate the socioendocrinology of free-ranging common marmoset males and verify that, in contrast to daughters, the reproductive suppression of sons is not based on physiological inhibition of their gonads.

Behavior and progesterone levels in Callithrix jacchus females

In callitrichids, and especially in the Callithrix and Saguinus genera, reproductive suppression maintains the breeding exclusivity of dominant females. It has been suggested that dominance may be inferred from agonistic behavior of females. The purpose of this study was to assess the adequacy of behaviors as indicators of hormonal status in Callithrix jacchus females. Two paires of twin females were observed for affiliative, agonistic and sexual behaviors for 20 weeks, in four stages of increasingly potential competition for one male. During the same period, blood samples were taken regularly for progesterone determination by ELISA. The two pairs differed markedly as to behaviors and hormonal status: pair 1 showed a well established behavioral dominance and only one ovulating female from the beginning of the observation period; pair 2 showed competition for dominance until the last stage of observation, when one of the females started ovulating. Correlations between behaviors and progesterone levels showed differences between subordinate and dominant females mostly in pair 2. Although limited in number of animals studied, these results suggest that there is a relationship between behavior and hormones in female marmosets, but this relationship may be useful in the identification of the physiological status of females only in groups where the dominance is not well estblished

The effect of parturition on the interactions within pairs of common marmosets (Callithrix jacchus)

The relationship within common marmoset (Callithrix jacchus) pairs is based on pair-bond formation. This pair-bond is important for the successful rearing of the young and for the enhancement of reproductive success. Female marmosets bear twins which are carried mainly by males starting on the first day after the birth of the infants. Little is known, however, about the patterns of sociosexual interaction between callitrichid pairs and how these interactions change after the arrival of offspring. To evaluate the effect of parturition on these interactions, three heterosexual pairs of common marmosets were observed for four weeks before and four weeks after the birth of infants. The animals were kept in individual outdoor cages of the Nucleo de Primatologia, under environmental conditions. The time spent in proximity was mainly attributable to the initiative of females before parturition and the iniatiative of males after the offspring arrived. Males were groomed more before than after the birth of infants. In contrast, the amount of grooming received by females was the same in the two situations. These observations suggest that the relationship within pairs of common marmosets is slightly modified by the birth of infants and indicates that males and females could be using different strategies to enhance their reproductive success