Pedro Mayor

Anatomicohistological Characteristics of the Tubular Genital Organs of the Female Collared Peccary (Tayassu tajacu) from North‐eastern Amazon

The present study examines anatomical and histological characteristics of tubular genital organs and its relationships with the reproductive state of 24 wild adult collared peccary (Tayassu tajacu) females. The tunica mucosa of the uterine tube presents a pseudostratified, intermittently ciliated columnar epithelium. The epithelial secretory cells of pregnant females and females in the luteal phase of the oestrous cycle became taller than the ciliated cells and showed abundant apical secretory blebs, whereas secretory cells of females in the follicular phase showed abundant mucous secretory activity (periodic acid‐Schiff positive cells). The uterus is composed of two narrow and convoluted uterine horns, separated by the velum uteri, a small uterine body and a long and muscular cervix. The endometrial lining of both uterine horns and body is a monostratified, columnar ciliated epithelium. Pregnant females and females in luteal phase showed a more developed hyperplasia of the endometrial simple tubular glands than females in the follicular phase. The cervix presents interdigitated rows of mucosal prominences that project into the lumen, structures similar to pulvini cervicali, occluding the cervical canal. In pregnant females, the endocervical canal was filled by a viscous cervical secretion. Females in follicular phase presented a thicker vaginal epithelium than pregnant females and females in luteal phase. The present study suggests that the collared peccary female showed different histological features of the uterine tubes, uterus and vagina in accordance with the reproductive state of the females.

Functional anatomy of the ovaries of wild brush-tailed porcupines (Atherurus africanus, Gray 1842) from Gabon

The brush-tailed porcupine Atherurus africanus is an important source of meat for local people in tropical forested areas of Central Africa. Information on the biology of this species in free-ranging conditions is scarce. Data on its reproduction and productivity are essential to establish accurate management practices in the exploitation of this rodent. In order to provide data on the reproductive physiology and to assess the prolificacy of the brush-tailed porcupine in the wild, the structural and functional anatomy of the ovaries of free-ranging females were studied. Twenty-two female carcasses were obtained from various markets in Libreville, Gabon, between August 1995 and February 1997. Reproductive tracts were macroscopically examined for the presence of embryos or foetuses. The ovaries were embedded in paraffin wax or plastic and examined by light microscopy. The morphology and constituent cell types of the ovaries were similar to those described for other hystricognath rodents. All pregnant females had only one embryo or foetus and the number of corpora lutea (CL) per female was 19.9 a 5.4 (mean diameter a sd, 1709 a 421 mm), including one CL of pregnancy (diameter, 4821 a 1364 mm). Also, 8.9 a 6.8 accessory CL per female in the pre-implantation and embryonic stages of pregnancy (diameter, 1629 a 463 mm) were observed. The average active luteal volume was high (115.6 a 73.5 mm 3 ). The mean number of antral follicles in the adult females was 24.6 a 9.9. The study confirms that the brush-tailed porcupine is a mono-embryonic species, as observed in captive breeding experiences, but polyovular, suggesting important ovum mortality. This unusual reproductive feature in a mammalian species gives this rodent a low reproductive productivity. Therefore, A. africanus could be more susceptible to the effects of hunting than generally thought.

Monitoring of leptospirosis seroprevalence in a colony of captive collared peccaries (Tayassu tajacu) from the Peruvian Amazon.

Leptospirosis, an endemic zoonoses, is maintained in the environment by several wildlife species in the Peruvian Amazon. In order to evaluate the possible role of collared peccaries (CP) in the maintenance this disease, two serological surveys of leptospirosis were performed and zootechnical parameters were monitored in a captive CP colony in an interval of 27 months. Total seroprevalence changed from 100% (n=27) to 86.4% (n=22), with reactions to a diversity of serogroups of zoonotic importance. Serological reactions to Leptospira licerasiae serogroup Iquitos, a new species recently identified locally and Leptospira interrogans serogroup Icterohaemorrhagiae were highly prevalent. The observation of leptospiral antibodies in both surveys, changes on serological reactions to different serogroups in large part of the herd and poor reproductive performances, provided an indication of the role of CP farms as a favourable environment for maintaining leptospirosis. Further research regarding the role of CP in the epidemiology of leptospirosis in the Peruvian Amazon is encouraged.

Antibodies against Leptospira spp. in Captive Collared Peccaries, Peru

To the Editor: Leptospirosis is endemic to tropical South America and is a major public health problem for persons living in some regions of the Amazon Basin (1–3). For local inhabitants, the collared peccary (Tayassu tajacu) represents a major source of meat and income and is one of the most hunted species. As a result, several farms are attempting to produce captive collared peccaries (4). Although spirochetes have been isolated from bats, marsupials, and rodents in the Peruvian Amazon (5), local popular game animals have not been tested. From May through December 2003, 96 collared peccaries from 4 experimental farms in 2 Amazonian provinces of Peru (Loreto and Ucayali) were surveyed for antibodies against Leptospira spp. Although the initial stock of each farm came from the wild, most animals had been born in captivity, remained on their respective farms, and had no contact with animals from the different farms. Blood samples were taken from animals that were born or maintained on the farm for ≥6 months, were in good physical condition, and showed no signs of disease. Samples that had been hemolyzed or otherwise contaminated were discarded, leaving optimal samples from 96 animals (sex ratio 1:1, 71% ≥1 year of age). The microscopic agglutination test was performed with a panel of 24 antigens belonging to 17 serogroups of Leptospira spp. used for screening surveys at the National Leptospirosis Reference Laboratory. An additional distinct strain, obtained from a febrile human patient in the Peruvian Amazon and provisionally designated as Var10, was added (2). Serum samples were considered positive if they had 50% agglutination and titers >100 (6). Chi-square tests were used for statistical comparisons of sex and age; significance was set at p<0.05. Among the screened samples, 64.6% reacted to 15 serovars (strains) that belong to 11 serogroups (Table). Seroprevalence did not differ significantly in relation to sex or age. Var10 was the most prevalent (56.2%) strain. This strain was isolated from a human patient in Iquitos (Loreto, Peru) and involved in recent outbreaks in the northern Peruvian Amazon (2); its taxonomic classification is pending. In terms of its distribution, 32 peccaries had positive results for Var10 only; 12 serum samples were reactive to >1 known serogroup. Leptospira sp. Var10 reacted mainly with serogroups Australis and Hebdomadis. Maximum titers were 6,400 for serogroup Tarassovi and 3,200 for Icterohaemorraghiae. High seroprevalence (15.6%) against serogroup Australis (serovar bratislava) has been reported in collared peccaries and in feral and domestic pigs (7,8) Table Prevalence of antileptospiral agglutinins per positive serogroup in captive collared peccaries, Peruvian Amazon, May 2003–Dec 2003* Seroprevalence on the farm in Loreto (n = 27) was 100%. At this farm, peccaries are kept near aquatic species and numerous ponds of stagnant water, which provide an ideal environment for the development of Leptospira spp. Because of recent human leptospirosis outbreaks in the area (2), 3 of the peccary caretakers were tested for antibodies against Leptospira spp.; their results were negative. Although similar to animals described in previous reports (7,9), none of the sampled animals showed evidence of disease at the time of sampling; however, absence of clinical disease does not exclude the possibility of subclinical or past infections. Furthermore, the high prevalence of antibodies to multiple serotypes suggests a wide exposure to Leptospira spp. Despite reports that suggest the collared peccary could act as a reservoir for Leptospira spp. (7,9), the finding of high antibody titers in some individual animals could indicate that collared peccaries are incidental rather than reservoir hosts. However, the prevalences found at 4 distant farms also indicate that this species could play some role in the maintenance and spread of leptospirosis in the Amazon Basin. Multiple titers to different serovars or serogroups in the same serum sample are common with serologic testing and difficult to interpret. Multiple titers can result from cross-reactions between different serovars or from true multiple infections (10). Regardless, serologic tests are only indicative of exposure to leptospires. Further efforts are necessary to isolate lepstospires from the urine or renal tissue of collared peccaries to confirm the presence of spirochetes and their potential dissemination into the environment. Our findings indicate that persons who have contact with collared peccaries and their products, particularly animal caretakers, researchers, hunters, and game traders, are at risk for zoonotic disease (3). Because further wildlife production in the Peruvian Amazon is expected, movement of animals and high animal densities could increase the chances of spirochete transmission within and between the farms. Therefore, precautions should be taken to limit the potential risks for leptospirosis transmission to domestic animals and humans.

Reproductive biology of the wild red brocket deer (Mazama americana) female in the Peruvian Amazon

Knowledge of the reproductive biology is critical for the development of management strategies of the species both in captivity and in the wild, and to address conservation concerns regarding the sustainable use of a species. The present report characterizes some aspects of the reproductive biology of the wild red brocket deer inhabiting the North-eastern Peruvian Amazon region, based on the anatomical and histological examination of the female reproductive organs of 89 wild adult females in different reproductive states. The red brocket deer female presented ovarian follicular waves involving the synchronous growth of a cohort of an average 25 follicles but only one follicle generally survived and continued development, reaching maturity at 4mm. Mean ovulation rate was 1.14 and litter size was 1 fetus. Females presented a low rate of reproductive wastage of 14.3% of embryos. Among the 89 adult females studied, 41 (46.1%) were pregnant and 48 (53.9%) were non-pregnant females. In the Northeastern Peruvian Amazon, conceptions occurred year-round in the red brocket deer but there were peaks in the rate of conception. Estimated yearly reproductive production was 0.76-0.82 young per adult female. Most pregnant females in advanced stage of pregnancy had at least one active CL, suggesting the persistence of CL throughout gestation.

Reproductive performance of the wild white-lipped peccary (Tayassu pecari) female in the Peruvian Amazon

The ability of any species to support high hunting pressures depends on its reproductive efficiency. Based on the gross anatomic examination of 208 adult female reproductive tracts, we characterised the reproductive biology of the wild white-lipped peccary in the northeastern Peruvian Amazon. White-lipped peccary apparently bred year round in the northeastern Peruvian Amazon, and the number of pregnant females was 80 (38.4%). Mean ovulation rate was 2.09 ± 0.47 CLs, and litter size was 1.60 ± 0.49 embryos or foetuses per pregnant female. A phenomenon of embryo migration was observed in the 27.5% of pregnant females. Estimations suggest 0.89 births per year and a yearly reproductive production of 1.42 piglets per pregnant female. Females in the late pregnancy stage showed a higher hunting vulnerability that could be an important restrictive factor for the reproductive efficiency of the wild white-lipped peccary populations in the Peruvian Amazon.

Reproductive functional anatomy and oestrous cycle pattern of the female brush-tailed porcupine (Atherurus africanus, Gray 1842) from Gabon.

In the present study, we examined certain features of the functional anatomy of the female genital tract of the wild brush-tailed porcupine (Atherurus africanus) to obtain data on the reproductive biology of this African forest rodent. Two consecutive experiments were performed. The aim of the first was to establish macroscopic and microscopic features of the genital organs, and to explore correlations between predominant ovarian structures and vaginal contents in 20 wild, mature females. In the second experiment, we inspected the external genitalia and vaginal smears of a further 10 females in captivity on a daily basis for 90 days. The uterus of the brush-tailed porcupine is bicornuate and composed of two separated uterine horns, a uterine body and cervix. The genital tract does not present a vaginal vestibule. Thus, there is no portion common to genital and urinary tracts. Females in the follicular phase of the oestrous cycle showed increased cornification of the vaginal epithelium and a high density of eosinophilic cells in vaginal smears. The vulva and vaginal opening were open, reddish and tumefacted. In luteal phase or in pregnancy, epithelial cornification and eosinophilic features were notably reduced and the vagina presented a pale, non-tumefacted vulva and a vaginal closure membrane. Females in captivity showed spontaneous cycles, a polyoestrous reproduction pattern and, based on features of the external genitalia and vaginal smears, their oestrous cycle length was 27.1+/-6.4 days (n=12).

Water contamination from oil extraction activities in Northern Peruvian Amazonian rivers

Oil extraction activities in the Northern Peruvian Amazon have generated a long-standing socio-environmental conflict between oil companies, governmental authorities and indigenous communities, partly derived from the discharge of produced waters containing high amounts of heavy metals and hydrocarbons. To assess the impact of produced waters discharges we conducted a meta-analysis of 2951 river water and 652 produced water chemical analyses from governmental institutions and oil companies reports, collected in four Amazonian river basins (Marañon, Tigre, Corrientes and Pastaza) and their tributaries. Produced water discharges had much higher concentrations of chloride, barium, cadmium and lead than are typically found in fresh waters, resulting in the widespread contamination of the natural water courses. A significant number of water samples had levels of cadmium, barium, hexavalent chromium and lead that did not meet Peruvian and international water standards. Our study shows that spillage of produced water in Peruvian Amazon rivers placed at risk indigenous population and wildlife during several decades. Furthermore, the impact of such activities in the headwaters of the Amazon extended well beyond the boundaries of oil concessions and national borders, which should be taken into consideration when evaluating large scale anthropogenic impacts in the Amazon.

Polycystic echinococcosis in Pacas, Amazon region, Peru.

In the Peruvian Amazon, paca meat is consumed by humans. To determine human risk for polycystic echinococcosis, we examined wild pacas from 2 villages; 15 (11.7%) of 128 were infected with Echinococcus vogeli tapeworms. High E. vogeli prevalence among pacas indicates potential risk for humans living in E. vogeli–contaminated areas.

Refining Reproductive Parameters for Modelling Sustainability and Extinction in Hunted Primate Populations in the Amazon

Primates are frequently hunted in Amazonia. Assessing the sustainability of hunting is essential to conservation planning. The most-used sustainability model, the ‘Production Model’, and more recent spatial models, rely on basic reproductive parameters for accuracy. These parameters are often crudely estimated. To date, parameters used for the Amazon’s most-hunted primate, the woolly monkey (Lagothrix spp.), come from captive populations in the 1960s, when captive births were rare. Furthermore, woolly monkeys have since been split into five species. We provide reproductive parameters calculated by examining the reproductive organs of female Poeppig’s woolly monkeys (Lagothrix poeppigii), collected by hunters as part of their normal subsistence activity. Production was 0.48–0.54 young per female per year, and an interbirth interval of 22.3 to 25.2 months, similar to parameters from captive populations. However, breeding was seasonal, which imposes limits on the maximum reproductive rate attainable. We recommend the use of spatial models over the Production Model, since they are less sensitive to error in estimated reproductive rates. Further refinements to reproductive parameters are needed for most primate taxa. Methods like ours verify the suitability of captive reproductive rates for sustainability analysis and population modelling for populations under differing conditions of hunting pressure and seasonality. Without such research, population modelling is based largely on guesswork.