Morfologia e dinâmica testicular em cutias (Dasyprocta prymnolopha) adultas / Testicular morphology and dynamic in adult agoutis (Dasyprocta prymnolopha)

Este trabalho objetivou apresentar a caracterização da morfologia do testículo de cutia (Dasyproctaprymnolopha) macho, com o intuito de colaborar com o conhecimento da morfofisiologia reprodutiva da espécie. Foram utilizados testículos de 47 animais, com idade entre um e dois anos, pesos homogêneos (2,08 ± 0,23kg), oriundos do Núcleo de Estudos e Preservação de Animais Silvestres do Centro de Ciências Agrárias da Universidade Federal do Piauí. As estruturas foram dissecadas, descritas, e fragmentos foram processados para a microscopia de luz, sendo, posteriormente avaliada a atividade gonadal. Observou-se que os testículos são órgãos elipsoides alongados, podendo ser encontrados na região inguinal ou na cavidade abdominal, não apresentando um escroto bem delimitado. Verificou-se também parênquima com característica histológica padrão para o órgão em mamíferos, com a identificação de oito tipos de associações celulares, caracterizando os estádios do ciclo do epitélio seminífero, com menor e maior frequência dos estádios 3 e 5, respectivamente.(AU)

This study meant to characterize the morphology of the testicle from (Dasyprocta prymnolopha) agouti males, in order to collaborate with the knowledge of reproductive morphophysiology of the specie. Testicles were used from 47 animals aged between 1 and 2 years, homogeneous weight (2.08±0.23kg), coming from the Centre for the Study and Conservation of Wild Animals of Agricultural Sciences Center of the Federal University of Piauí. The structures were dissected, described and fragments were processed for light microscopy, and, subsequently, gonadal activity was evaluated. Testes were observed to be elongated ellipsoidal bodies that can be found in the groin or in the abdominal cavity, not having a clearly defined scrotum. We also could see parenchymal with standard histological characteristic for the mammalian body, with the identification of eight types of cell associations, characterized epithelium Seminiferous stages of the cycle, with lower and higher frequency of stages 3 and 5, respectively.(AU)

Pregnancy in Hystricomorpha: gestational age and embryonic-fetal development of agouti (Dasyprocta prymnolopha, Wagler 1831) estimated by ultrasonography.

Thirty-one pregnant agoutis, between Days 9 and 103 of gestation (Day 1 = day of detection of sperm in the vaginal smear), underwent B-mode ultrasonography; gestational sac diameter (GSD), crown-rump length (CRL), embryonic-fetal diameter (EFD), and placenta diameter (PD) were measured. There were positive correlations (P < 0.05) between GSD and CRL (r = 0.98), GSD and PD (r = 0.88), CRL and PD (r = 0.86), days of gestation (DG) and CRL (r = 0.85), and DG and PD (r = 0.73). The gestational sac was first observed on Day 14. The embryo was first seen on Day 18 in 9/31 of pregnant agoutis and on Day 22 in 20/31 of pregnant agoutis. Heartbeats were detected from the Day 25 and placentas were observed in 100% of the animals from Day 25. Early limb bud and ossification of the fetal skull were identified on Days 27 (15/31) and 45 (24/31), respectively. Fetal orientation (head and body) was evident from Day 40, the stomach, liver and lungs were identified on Day 50, the kidneys were reliably seen only on Day 55, and the aorta and vena cava were seen on Day 70. The fetal bowel and the urinary bladder were the last structures to be observed (Day 85). Ultrasonography was effective for early pregnancy diagnosis in agouti and for obtaining information on embryonic and fetal structures that could be used to predict gestational age and birth, thereby contributing to their reproductive management in captivity.

Daily sperm production and testicular morphometry in goats according to external scrotal conformation.

The present study aimed to compare testicular histology and the testicular cell population as well as spermatogenic efficiency in goats with different scrotal conformations. Eighteen goats were divided into 3 groups: Group I - goats without bipartition of the scrotum, Group II - animals with bipartition of the scrotum up to 50% of the testicular length, Group III - goats with scrotal bipartition more than 50% of the testicular length. In goats in Groups I, II and III, the values for the volume density of seminiferous epithelium were 68.9 ± 0.6%, 71.5 ± 2.8% and 73.4 ± 4.7% (P<0.05), the height of the seminiferous epithelium were 60.2 ± 4.9 µm, 61.0 ± 5.0 µm and 73.1 ± 6.6 µm (P<0.05), total length of seminiferous tubules found for Groups I, II and III were 2091.9 ± 27 m, 2172.5 ± 24.1 m, and 2340.1 ± 14 m (P<0.05), number of Sertoli and Leydig cells were 1.8 ± 0.4×10(9) and 1.4 ± 0.1×10(9), 2.2 ± 0.4 and 2.2 ± 0.7×10(9), and 2.5 ± 0.1 10(9) and 2.3 ± 0.5 10(9) (P<0.05) and daily sperm production observed were 2.1 ± 0.3×10(9), 2.8 ± 0.4×10(9), and 3.1 ± 0.7×10(9) (P<0.05). In conclusion, goats with greater scrotal bipartition have a greater capacity to produce reproductive cells that is reflected in a greater reproductive potential.

Collection and evaluation of epididymal sperm in captive agoutis (Dasyprocta aguti).

The objective was to establish a protocol for the collection and evaluation of epididymal sperm in agoutis. Eight males (1-2 y old) underwent left orchidectomy and epididymal sperma were collected by retrograde flush. Average values were flush volume 32 µL, pH 6.9, sperm concentration 748 x 10(6) sperm/mL, with motility 86.5% and vigor 4.6. Viable sperm were present in all flush samples; 66% of sperm were alive, and 41.9% of sperm responded positively to the hypoosmotic test (using distilled water). There were 21.1% morphologically abnormal sperm, of which 2.0 and 19.1% were primary and secondary defects, respectively. The acrosome was intact in 99.5% of sperm. The sperm head was 4.89 ± 0.41 µm long and 3.13 ± 0.35 µm wide, with an area of 13.01 ± 2.01 µm(2). Midpieces were 5.33 ± 0.44 µm long and 0.98 ± 0.13 wide, sperm tails were 29.91 ± 2.29 µm, and overall sperm length was 40.12 ± 2.44 µm. In conclusion, epididymal sperm collection from agoutis was satisfactory; the collected sperm has the potential to be stored, facilitating development of other reproductive biotechnologies for this species.

Arterial supply of the penis in agoutis (Dasyprocta prymnolpha, Wagler, 1831).

The arterial vascularization of agoutis' penis (Dasyprocta prymnolopha) were analysed using ten male adults from 'Núcleo de Estudos e Preservação de Animais Silvestres da Universidade Federal do Piauí' (FUFPI/IBAMA n degrees 02/99). Among the total number of specimens, six animals had natural death and were members of the research collection of the Laboratory of Anatomy, and four were killed after anaesthesia. Stained bi-centrifugated-Cis-I-4 latex was injected in arterial vessels responsible for penis vascularization throughout the abdominal portion of aorta. The samples were fixed in 10% formaldehyde solution and arteries were dissected. The penile artery is originated as a branch of internal pudendal artery. At the level of ischiatic arch, the penile artery project two branches, the penile dorsal and the deep arteries; those arteries irrigates the penile dorsal surface and the corpus cavernosum penis. The penile dorsal arteries have an independent course up to the glans penis. Based on the conditions of this work a remarkable similarity regarding the distribution of vessels destined to the agouti penis when compared to other domestic, wild and lagomorph rodents as rabbits.