Agouti Dasyprocta Research Articles

Relationship between season and spermatozoa traits of captive-reared agoutis from Brazilian semiarid.

For the development of efficient management and conservation strategies for wild rodent species, understanding the aspects related to their reproduction, including the interaction of this physiological function with the environment, is essential. This study aimed to evaluate the impacts of weather changes derived from a semiarid region's dry and rainy seasons on the epididymal sperm characteristics of red-rumped agouti (Dasyprocta leporina), a histricognath rodent, still little studied, which inhabits the Brazilian Caatinga. The sperm from the epididymal cauda of 14 agoutis were collected, seven individuals per season (dry and rainy). Samples were evaluated for kinetic parameters, membrane structural and functional integrity, mitochondrial activity, morphology, and morphometry. The environmental variables were measured: maximum air temperature, relative humidity, wind speed, solar radiation, and the total rainfall for dry and rainy seasons were, respectively, 36.2 and 34.1°C, 66.8 and 80.1%, 4.0 and 1.9m/s, 527.3 and 441.8 W/m2, and 0.2 and 517.7mm. There were strong correlations between some sperm parameters and environmental variables, mainly those related to the acquisition of sperm mobility. Sperm concentration and the number of sperm collected were higher in the dry (1028.7 sperm/mL × 10⁶ and 1361.2 × 106 sperm) than in the rainy season (758.9 sperm × 10⁶/mL and 714.6 sperm × 106). During the rainy season, there were fewer sperm defects, higher sperm metrics, and higher membrane structural integrity with mitochondrial activity. Regarding motility patterns, the increases during the rainy season stand out in total and progressive motility, VAP, VSL, VCL, and subpopulations of rapid sperm. In summary, our results suggest that the adverse climatic conditions of the dry season in the semiarid region, mainly high solar radiation and temperature, considerably impair the epididymal sperm quality of red-rumped agoutis. On the contrary, the largest amount of sperm was obtained during this season, probably due to compensatory and adaptive mechanisms of the species to enable its reproduction throughout the year.

Red-rumped agouti (Dasyprocta leporina linnaeus, 1758) yolk sac development during the early gestation stage

Red-rumped agouti (Dasyprocta leporina linnaeus, 1758) yolk sac development during the early gestation stage

Utilizing Agricultural By-Products for Sustainable Agouti (Dasyprocta leporina) Diets: Evaluating Low-Cost Feed Alternatives in Trinidad and Tobago, West Indies

The agouti (Dasyprocta leporina) is a promising protein source in the Caribbean, Mexico, and South America. This study assessed the impact of three by-product diet formulations on intensively reared agoutis, including a cost analysis and nutritional evaluation as well as the nutritional composition, digestibility, and economic viability of three experimental diets. Sixteen adult male agoutis were individually housed at the University of the West Indies’ Field Station. After a two-week acclimatization, a four-week data collection phase followed. The four treatments included a control diet of commercial rabbit pellets and three experimental diets with varying by-product ratios. Key findings revealed that Treatment 2 had elevated Dry Matter, Crude Fat, and fiber but potentially compromised digestibility due to higher fiber and lignin. Treatment 1 resulted in the highest morbidity and was discontinued after two weeks due to significant weight loss but demonstrated the most cost-effective results, with the lowest variable cost per 45 kg, the lowest feeding cost to reach 3 kg, and the highest gross margin. Treatment 2 effectively maintained animal weight. Treatment 3 showed promising growth due to low levels of Neutral Detergent Fiber (NDF) and Acid Detergent Lignin (ADL). Alternative dietary feedstuffs from agricultural by-products show potential for sustaining body weight in adult male agoutis, but further research is needed to refine nutritional requirements for growing agoutis.

Neotropical mammal responses to megafires in the Brazilian Pantanal.

The increasing frequency and severity of human-caused fires likely have deleterious effects on species distribution and persistence. In 2020, megafires in the Brazilian Pantanal burned 43% of the biome's unburned area and resulted in mass mortality of wildlife. We investigated changes in habitat use or occupancy for an assemblage of eight mammal species in Serra do Amolar, Brazil, following the 2020 fires using a pre- and post-fire camera trap dataset. Additionally, we estimated the density for two naturally marked species, jaguars Panthera onca and ocelots Leopardus pardalis. Of the eight species, six (ocelots, collared peccaries Dicotyles tajacu, giant armadillos Priodontes maximus, Azara's agouti Dasyprocta azarae, red brocket deer Mazama americana, and tapirs Tapirus terrestris) had declining occupancy following fires, and one had stable habitat use (pumas Puma concolor). Giant armadillo experienced the most precipitous decline in occupancy from 0.431 ± 0.171 to 0.077 ± 0.044 after the fires. Jaguars were the only species with increasing habitat use, from 0.393 ± 0.127 to 0.753 ± 0.085. Jaguar density remained stable across years (2.8 ± 1.3, 3.7 ± 1.3, 2.6 ± 0.85/100 km2), while ocelot density increased from 13.9 ± 3.2 to 16.1 ± 5.2/100 km2. However, the low number of both jaguars and ocelots recaptured after the fire period suggests that immigration may have sustained the population. Our results indicate that the megafires will have significant consequences for species occupancy and fitness in fire-affected areas. The scale of megafires may inhibit successful recolonization, thus wider studies are needed to investigate population trends.

Identification of mammals based on hair microstructure: Methodological adaptations and new morphological patterns

The characterization of patterns of hair microstructure is an important instrument for studying the diet and ecology of mammals, representing an accessible method for identifying predators and their prey. The present study aimed to: (1) describe methodological adaptations developed to optimize traditional guard hair analysis protocols; (2) propose adjustments in the classification of morphological patterns of medulla and cuticle; and (3) establish the microstructural pattern of Brazilian mammals’ hair to assist in the identification of prey and predators in studies based on fecal samples. Hairs from 53 mammal species, including small (n = 16), medium (n = 28) and large size (n = 9), distributed in 24 families and nine orders were analyzed. The orders with the most species analyzed were Carnivora (n = 14), Rodentia (n = 13) and Didelphimorphia (n = 8), while the most representative families were Didelphidae (n = 8), Cricetidae (n = 7) and Felidae (n = 6). Among the species, 13 (24.5% of the total) did not have the microstructural patterns described in studies developed previously in Brazilian territory: Alouatta guariba, Blarinomys breviceps, Bradypus torquatus, Callicebus personatus, Callithrix geoffroyi, Dasyprocta leporina, Hylaeamys seuanezi, Potos flavus, Priodontes maximus, Rhipidomys mastacalis, Sapajus robustus, Sylvilagus minensis and Tayassu pecari. More descriptive nomenclatures were proposed regarding the observed patterns and new patterns were described for species evaluated in previous studies. Our results contribute to the diagnosis of species to be more accurate, contributing to the development of future studies.

First observations of foraging relationship between white-shouldered fire-eye Pyriglena leucoptera (Passeriformes) and Azara’s agouti Dasyprocta azarae (Rodentia)

First observations of foraging relationship between white-shouldered fire-eye Pyriglena leucoptera (Passeriformes) and Azara’s agouti Dasyprocta azarae (Rodentia)

Cryopreservation efficiency of red-rumped agouti (Dasyprocta leporina) sperm obtained from different origins through epididymal retrograde flushing or electroejaculation

This study investigated whether the origin of sperm (epididymal vs. ejaculate) affects the cryopreservation efficiency in agouti (Dasyprocta leporina). Five sexually mature agoutis underwent electroejaculation, resulting in obtaining four semen samples. After 15 days, the same animals were euthanized, and through retrograde flushing, sperm samples were obtained from the epididymis tails. In both collection methods, samples were evaluated for sperm parameters (sperm concentration, motility, vigor, membrane integrity, osmotic response, and morphology). Then, samples were diluted in ACP 109c, added with 20% egg yolk, and a final concentration of 6% glycerol. Finally, the samples were packaged in 0.25 mL straws and frozen in liquid nitrogen. After one week, samples were thawed and evaluated in the same way as fresh samples, with the addition of membrane integrity analysis using fluorescent probes (C-FDA/PI) and computerized analysis (CASA). Immediately after obtaining the sperm, samples obtained directly from the epididymis presented higher values (P ≤ 0.05) than those obtained by electroejaculation concerning the parameters of volume, sperm concentration, and total number of sperm (1,398.25 ± 206.0 x106 and 184.5 ± 78.0 x106 sperm). On the other hand, in the classical evaluation of the other sperm parameters and the computerized analysis (CASA) after thawing, such as total motility, no statistical differences were observed between sperm from both origins (ejaculate: 16.7 ± 8.2% and epididymal: 24.8 ± 12.0%, P > 0.05). This demonstrates the possibility of direct application of the cryopreservation protocol for agouti (D. leporina) sperm obtained via the epididymis or ejaculate.

Abdominal aortic branches of red-rumped agouti (Dasyprocta leporina Linnaeus, 1758).

Understanding the cardiovascular system is fundamental in diagnosing pathologies and interpreting exams, such as contrast radiographs. In this context, the present study describes the collateral abdominal aorta artery branches of red-rumped agouti. Ten red-rumped agoutis, six males and four females, were assessed. The vascular system was perfused with Neoprene 450 latex coloured with a yellow pigment, dissected and analysed. Three euthanized animals were perfused with a barium sulfate solution (1 g mL-1 ) associated with latex Neoprene 450 at a 1:3 ratio to obtain contrast-enhanced radiographs. The abdominal aorta emitted the celiac artery, which in turn originated the left gastric, hepatic and splenic arteries. The second collateral branch comprised the cranial mesenteric artery, followed by the renal arteries, which emitted the adrenal arteries, with the caudal emergence of the gonadal arteries. The caudal mesenteric artery appeared in a caudal direction. The abdominal aorta divided after reaching the pelvic cavity entrance, originating the right and left common iliac arteries. Before its bifurcation, the abdominal aorta dorsocaudally emitted its last collateral branch, the median sacral artery. The collateral branches of the aorta, therefore, resemble previously described rodent patterns, with few variations.

Interactions Among Sucrose and Concentrations of Serum Fetal Bovine on the Cryopreservation of Somatic Cells Derived from Red-Rumped Agoutis

BACKGROUND: The synergistic action among the different extracellular cryoprotectants could improve somatic cell quality after thawing and provide bases for the formation of biobanks for redrumped agoutis. OBJECTIVE: This study evaluated the interactions among sucrose (SUC) and concentrations of serum fetal bovine (FBS) on the cryopreservation of somatic cells derived from redrumped agoutis. MATERIALS AND METHODS: Cells were cryopreserved with 10% dimethyl sulfoxide and different concentrations of FBS (10%, 40%, and 90%) with or without 0.2 M SUC, totaling six comparison groups. Non-cryopreserved cells were used as a control. Cells were evaluated for viability, metabolic activity, proliferative activity, reactive oxygen species (ROS), mitochondrial membrane potential (ΔΨm) and apoptosis levels. RESULTS: No difference was observed among cryopreserved with DMSO containing (10FBS, 10FBS-SUC, 40FBS, 40FBS-SUC, 90FBS, 90FBSSUC) and non-cryopreserved groups for viability, metabolic activity, proliferative activity, and ROS levels. Interestingly, only cells cryopreserved with 90% FBS and SUC maintained the ΔΨm like the control. This indicates that at high concentrations of FBS, SUC contributes to the maintenance of this parameter in cryopreserved cells. Moreover, at concentrations of 10% and 40% of FBS, SUC contributed to the maintenance of viability evaluated by the levels of apoptosis evaluated after thawing. In summary, we verified that 90% FBS and 0.2 M SUC promote greater ability of cells after thawing. Additionally, SUC positively acts in cryopreservation solutions containing 10% and 40% FBS. CONCLUSION: This information is essential to an understanding of the mechanisms involved in the interactions of extracellular cryoprotectants in somatic cell cryopreservation solutions of red-rumped agoutis.

Cysticercosis in free-ranging agoutis (Dasyprocta leporina) in the Eastern Brazilian Amazon.

The study describes the occurrence of cysticercosis in liver of 22 wild agoutis (Dasyprocta leporina) in the Brazilian Amazon. The phylogenetic analysis and microscopic characteristics of metacestodes in liver tissue sections, associated with the geographic distribution of the intermediate hosts indicated that a possibly novel Taenia sp. metacestode caused the parasitism. Additionally, two cases of hepatic co-infection by Taenia sp., Calodium sp. and Echinococcus oligarthra were also observed among the analyzed animals. The results point to the need for a better understanding of hepatotropic parasites among wild rodents in the Brazilian Amazon.

Anthelmintic usage on the performance of the Agouti (Dasyprocta leporina) reared intensively in Trinidad and Tobago, West Indies.

Anthelmintic drugs have been used strategically in livestock reared in the tropics. These drugs have been used in the treatment of endoparasitism which have resulted in an increase in the animals' performance. The agouti (Dasyprocta leporina) is a neo-tropical rodent with the potential for domestication and has been farmed intensively in Trinidad. However, the objective of this research was to investigate the effect of anthelmintic use of the growth performance of the agouti. In searching the literature, it was found that this type of study on the agouti has not been done. In this experiment fourteen weaned agoutis weighing 1kg were divided into two groups randomly. The first group (T1) was not given any anthelmintic treatment but the second group (T2) was treated with Endovet Ces® subcutaneously every three months. There were no significant differences (p > 0.05) between the two groups in the carcass weight, weight gain, dressing percentage (hot and cold), heart, lungs, skin, head and feet. However, a significant difference (p < 0.05) was seen between groups in the weight of liver and pluck. To the authors knowledge this is the first time that carcass parameters has been presented in literature. The live weight of the animals at the end of the experiment ranged from 2.4 kg to 2.6 kg and animals had a dressing percentage of 57% to 55%. The results are suggestive that the use of anthelmintic drugs in agoutis reared intensively had no significant effect on weight gain and dressing percentage.

Anthelmintic usage on the Reproductive Parameters in Captive reared Agoutis (Dasyprocta leporina) in Trinidad and Tobago, West Indies.

The agouti (Dasyprocta leporina) is a rodent that is found in the Neo-tropical region. This animal is hunted for its meat but has recently been reared in captivity as a source of meat protein in rural communities. A 20-month experiment was carried out to evaluate the effect of an anthelmintic on the reproductive performance of the agouti (Dasyprocta leporina) reared in captivity. This experiment was conducted in the humid tropics of Trinidad and Tobago. Sixteen animals (15 females, 1 male) placed in each of the two treatment groups in a completely randomized study design. In treatment 1 (T1) animals were given subcutaneous injections of Endovet Ces® (Ivermectin/Praziquantel) at 0.2 mg/kg every three months. Treatment 2 (T2) was the negative control group where animals were not exposed to an anthelmintic. Reproductive data were collected at parturition which included birth weight, litter weight, litter size and gender of offspring. The results showed that there was no statistical difference (p > 0.05) between the treatment groups with respect to birth weight, litter weight, litter size and gender. However, agoutis that were dewormed had a higher birth weight (220.24 g vs 209.1 g) and litter weight (369.8 g vs 343 g). The same values were obtained for the litter size (1.7 vs 1.7) and animals that were dewormed had a higher female offspring to male offspring (2.41:1 vs 1.11:1). This experiment demonstrated that the use of an anthelmintic strategically in the management of captive reared agoutis had no statistical effect (p > 0.05) on the reproductive parameters. Therefore, these animals can be kept in captive conditions without being dewormed and produce efficiently with proper feeding and housing management.

Evaluating the effects of different methods of estrus synchronization in the agouti (Dasyprocta leporina)

There has been limited work done on estrus synchronization or induction in the Dasyprocta species. This experiment sought to apply three different methods of estrus synchronization to fifteen agoutis (Dasyprocta leporina) which were placed into three treatments. Treatment 1 received gonadorelin acetate (Fertiline®) injections subcutaneously (40 µg); treatment 2 received two doses of dinoprost tromethamine (Lutalyse®) injections intramuscularly (2.5 mg) nine days apart and; treatment 3 received gonadorelin acetate (Fertiline®) injections subcutaneously (40 µg), followed seven days later by dinoprost tromethamine (Lutalyse®) injections intramuscularly (2.5 mg) and a second gonadorelin acetate (Fertiline®) injection subcutaneously (40 µg) given two days after. Daily vaginal swabbing, followed by cytological analysis was done until estrus was noted in all animals. All animals were successfully synchronized, with estrus being observed 17.40 ± 0.24, 7.25 ± 0.25 and 7.60 ± 0.24 days post treatment for treatments 1, 2 and 3, respectively. Return to estrus in females from treatment 1 was later than the other two treatments (p < 0.001), which can be due to the effect of a single gonadorelin actetate (Fertiline®) administration. Since this hormone has a luteotropic effect, and all animals were in their luteal phases, it would have maintained the life of the corpora lutea already present in these animals. The estrus cycle of D. leporina can therefore be synchronized using any of these three protocols, with the double PGF2α and OvSynch protocols demonstrating the fastest period of time for the onset of estrus.

Effect of different anesthetic protocols on erection, ejaculation and sperm parameters in red-rumped agoutis (Dasyprocta leporina) subjected to electroejaculation

Effect of different anesthetic protocols on erection, ejaculation and sperm parameters in red-rumped agoutis (Dasyprocta leporina) subjected to electroejaculation

Placental development in the early stages of red-rumped agouti pregnancy (Dasyprocta leporina Linnaeus, 1758).

Hystricomorpha rodents display a similar placentation model to humans. The present study was carried out considering the scarcity of information concerning the placental development in agouti. Describe the microscopy of the placenta, subplacenta and yolk sac of agoutis in early pregnancy and report on the inversion of the yolk sac. Fifteen females between the 14th-32nd day of gestation were used following euthanasia. Gestational buttons were collected, fixed, processed, stained to optical microscopy or immunohistochemistry. Chorioallantoic placenta (CP) ranged from conical to a half-sphere, as follows: from the 14th to 17th day, the CP displays an inverted "V" shape, predominantly formed by cytotrophoblasts; from 20 to 22 days, formed almost entirely by cytotrophoblasts; at 28 days, a half sphere, with distinct lobes and interlobular area, numerous maternal gaps delimited by syncytiotrophoblasts and trophoblast giant cells; at 32 days, globose and undergoing the maturation process. Subplacenta, located between decidua and CP, initially presents septa consisting of simple columnar epithelium and after 17 days, comprising stratified epithelium. Visceral yolk sac (VYS) is attached to two CP projections between 14 and 17 days, formed by a simple cubic epithelium and inverted. Between 20 and 22 days, the epithelium displays apical villous projections with cytoplasmic vacuoles and a vascularized mesoderm. After the 24th day, the VYS near the placenta is pleated, very vascularized and villous, with decreased villi sizes further away from the placenta. The agouti CP displays similar characteristics to other hystricomorpha, including placenta lobulation, a subplacenta and an inverted vitelline placenta.

Morpho-Histological Studies of the Gastrointestinal Tract of the Orange-Rumped Agouti (Dasyprocta leporina Linnaeus, 1758), with Special Reference to Morphometry and Histometry.

The morphology of the gastrointestinal tract (GI) is a strong indicator of a species' dietary habits. The objective of this study was to describe and quantitatively analyze the gross and microanatomy of the digestive tract of the orange/red-rumped agouti (Dasyprocta leporina) and relate it to the feeding habits of this animal. The digestive tracts of six adult males were used for this study. The results showed that the esophagus was thick (mean thickness of 1023.78 ± 28.97 μm) and lined by keratinized epithelium with scant esophageal glands. Mucosa-associated lymphocytic infiltration was robust throughout the GI tract. These findings suggest that the esophagus was well adapted to a coarse diet. The simple stomach with well-developed gastric glands in the fundus region (mean thickness of 605.39 ± 28.68 μm) was indicative of an adaptation to a carnivorous diet. The small intestine constituted approximately 80% of the length of the GI tract. The remarkable development of the jejunum with a greater villus length (mean thickness of 182.50 ± 27.38 μm) indicated a greater absorptive capacity in frugivorous and carnivorous diets. The long cecum and well-developed colon clearly indicated that the GI tract was well adapted to frugivorous and herbivorous diets. Overall, D. leporina showed that it is well adapted to an omnivorous diet. These results suggest that D. leporina can be fed a balanced omnivorous dry diet with a high protein content of plant or animal origin that is well suited to the architecture of the GI tract in captivity.

Blood Feeding Sources of Nyssomyia antunesi (Diptera: Psychodidae): A Suspected Vector of Leishmania (Kinetoplastida: Trypanosomatidae) in the Brazilian Amazon.

Present work aimed to identify blood feeding sources and attempt to detect Leishmania DNA in Nyssomyia antunesi, suspected vector of Leishmania sp., from a park in the urban center of Belém, the capital of Pará State, in the Brazilian Amazon. Entire bodies and gut contents of Ny. antunesi engorged females, previously captured in the urban park with Centers for Disease Control (CDC) light traps and aspiration on tree bases, were subjected to Leishmania and vertebrate DNA detection through amplification of the Leishmania mini-exon and vertebrate cytochrome b (cyt b) gene regions, respectively. The quality of DNA extraction from entire bodies was ensured through amplification of the dipteran cyt b region. The vertebrate cyt b amplicons were sequenced and compared with those available on GenBank. A maximum likelihood phylogenetic tree was constructed to assess the clustering patterns of these sequences. Leishmania DNA was not detected. The sequences of 13 vertebrate cyt b amplicons were considered informative, exhibiting similarity and clustering with the following six vertebrate species: Dasyprocta leporina (1), Cuniculus paca (1), Tamandua tetradactyla (4), Choloepus didactylus (4), Pteroglossus aracari aracari (2), Homo sapiens (1). The samples of D. leporina and C. paca were obtained from the CDC canopy, whereas the others were by aspiration from tree bases. The present results revealed the eclectic and opportunist blood-feeding behavior of Ny. antunesi, with birds and mammals, these last ones acting as potential reservoirs for Leishmania species, distributed throughout the vertical forest strata.

Medium- and large-sized mammals from Estação Biológica Fiocruz Mata Atlântica, Rio de Janeiro, south-eastern Brazil.

The Pedra Branca Forest is in a highly urbanised region of the central portion of Rio de Janeiro City and comprises the largest urban forest in the world (> 12,000 ha). The local flora and fauna are protected by three conservation units and the Estação Biológica Fiocruz Mata Atlântica (EFMA), which comprises 462 hectares on the east side of the remnant. The local biodiversity is still little known compared to other Atlantic Forest remnants from the Rio de Janeiro State. Here, we provide results of a survey of medium- and large-sized terrestrial mammals from the EFMA. In addition, we analysed the distribution of this fauna along three habitat types defined as Peridomicile, Transitional Forest and Forest Core. Sampling was performed from 2017 to 2020 and comprised a camera-trap survey, interviews with residents and local workers and occasional records. Results include occurrence records for 16 autochthonous and one allochthonous (Callithrix sp.) wild mammals, which are distributed into 14 families and seven orders, in addition to the presence of free-ranging domestic dogs and cats. Four species are in some category of threat of extinction at national or global levels. Amongst them, Leontopithecusrosalia (first record for the Rio de Janeiro City in more than a century) and Leopardusguttulus are classified as Vulnerable by IUCN. Most wild native species were registered in the three habitat types, but with differences in the frequency of records. Our results indicate that the presence of domestic dogs and cats influenced the species composition in each area, with Nasuanasua, Dasyproctaleporina and Didelphisaurita less frequent in places where domestic dogs and cats are more frequent. This is the first systematic effort to understand the occurrence and distribution of mid- and large-sized mammals in the Pedra Branca Forest.

Morphological, morphometric, ultrastructural, and functional evaluation of red-rumped agouti (Dasyprocta leporina) sperm during epididymal transit

The red-rumped agouti (Dasyprocta leporina) is a hystricognath rodent with reproductive anatomical peculiarities presenting as an intra-abdominal testes-epididymis complex. This study was carried out to describe, for the first time, details related to the morphological and functional changes in sperm along the epididymal transit in agoutis. The testes-epididymal complexes were sampled from seven sexually mature agoutis. Sperm from different epididymal regions (caput, corpus, and cauda) were collected using the floating technique, and their morphology, morphometry, ultrastructure, mitochondrial activity, membrane structural integrity, and kinetic parameters were determined. The number of sperm collected (823.5 ×106 sperm) was higher in the epididymis cauda. No significant differences in normal sperm morphology among the different epididymal regions (caput, 82.42%; corpus, 86.71%; and cauda, 88.86 %) were observed. The mean head length, head width, and tail length were highest in the caput (5.15 µm, 3.44 µm, and 32.04 µm, respectively), decreasing along the epididymal transit. Ultrastructure by scanning electron microscopy (SEM) revealed agglomeration of spermatozoa from caput and corpus, thus, enabling analysis of the gametes from only the epididymal cauda with clarity. Sperm from epididymis cauda showed the greatest proportion of membrane integrity and mitochondrial activity, followed by those from corpus and caput (79.71 %, 58.9 %, 47.7 %, respectively). Significant increase in total motility, progressive motility, velocity average pathway -VAP, velocity straightline – VSL, velocity curvilinear – VCL, and rapid sperm in the caput-corpus-cauda direction were observed. These novel data contribute to the knowledge of sperm maturation in the red-rumped agouti.

Evaluation of sperm membrane functionality during epididymal transit in red-rumped agouti (Dasyprocta leporina).

We studied the sperm membrane functionality through the epididymal transit by comparing different hypoosmotic solutions and verifying possible associations among osmotic response and functional parameters of sperm in red-rumped agouti (Dasyprocta leporina). For this purpose, epididymal sperm from six sexually mature male agoutis were collected via flotation. Then, analyses of sperm parameters and hypoosmotic swelling test using different hypoosmotic solutions (0, 50 and 200mOsm/L) in different regions of the epididymis (caput, corpus and cauda) were performed. There was an increase (p<.05) in the values for sperm concentration, the total number of sperm recovered, total and progressive motility, average path velocity, straight-line velocity, curvilinear velocity, and rapid and medium subpopulations following the caput-corpus-cauda direction. Regardless of the hypoosmotic solution, the agouti sperm membrane presented similar functional integrity in all the epididymal regions. Moreover, the highest (p<.05) osmotic responses were reached with the use of 50mOsm/L solution in comparison to 0 and 200mOsm/L for all the regions. Significant correlations among osmotic response and some sperm kinetic parameters were observed, especially in epididymal caput, while no correlations were found in the region of the cauda. In summary, red-rumped agouti sperm present similar membrane functionality during epididymal transit, but there are evident correlations among such functionality and sperm kinetic parameters, especially in the caput region. Moreover, we indicate the use of a 50mOsm/L hypoosmotic solution for the analysis of this parameter through the hypoosmotic swelling test.