Inclusion of cocoa bran in the diet of lambs and its effect on reproductive parameters.

The objective of the study was to evaluate the effect of the inclusion of cocoa bran in the diet of lambs and its effect on reproductive parameters. For this, 40 lambs were randomly assigned to four treatments, and including 0, 10, 20 and 30% levels of cocoa bran in the concentrate. Blood was collected to measure cholesterol and testosterone and semen for physical and morphological evaluation; testicular biometry and morphometry were also evaluated. There was significant difference (P < 0.05) in body weight and tubulosomatic index between the lambs in the control treatment and those in the 30% cocoa bran treatment. There was no difference in testicular biometry, physical and morphological parameters of fresh semen, testicular morphometry, and volumetric ratio between lambs in all the treatments (P < 0.05). In addition, there was no difference in plasma cholesterol or testosterone concentration (P > 0.05). Thus, it is possible to include up to 30% of cocoa bran in diet without affecting the reproductive parameters of lambs.

Characteristics of Bachaur bull semen.

The Bachaur is a mediumized draft purpose breed which has been recognized by ICAR-National Bureau of Animal Genetic Resources (NBAGR) Karnal, India, and presently is on the verge of extinction. Since there are no data regarding the seminal parameters of this breed, this work was performed to evaluate seminal parameters of freshly ejaculated semen. A total of three healthy breeding Bachaur bulls aged 2.5-5 years were selected for the study which were maintained under identical managemental conditions. Semen parameters of these bulls were studied across 10 ejaculates. The average scrotal circumference and testicular weight of the three bulls were 27.78 ± 1.2 cm and 400.67 ± 26.6 g, respectively. The average overall volume (mL), pH, concentration (million/mL), liveability (%), abnormality (%), HOST (%) and acrosome integrity (%) were 2.20 ± 0.19, 6.86 ± 0.06, 1245.60 ± 23.49, 85.09 ± 0.91, 4.13 ± 0.06, 81.16 ± 1.18 and 83.54 ± 1.32, respectively. The average overall mass motility of three Bachaur bulls was 3.57 ± 0.06 in 0-5 scale and individual motility averaged 84.78 ± 1.70 per cent. The volume of ejaculates in Bachaur bull seemed to be lower as compared to other exotic and Indian breeds. However, the semen parameters with regard to mass motility, liveability, abnormalities, hypo-osmotic swelling test (HOST) and acrosomal integrity seemed similar to other exotic and Indian breeds.

Testicular histomorphometric patterns and spermatogenesis dynamics of Oecomys bicolor tomes, 1860 (Rodentia: Cricetidae).

Although the order Rodentia does not present a high risk of extinction compared to mammals as a whole, several families demonstrate high levels of threat and/or data deficiency, therefore highlighting the need for targeted research and the application of ecological and reproductive data to the development of conservation actions. The order Rodentia, the largest among mammals, includes 9 families, and the family Cricetidae is the most diverse of the Brazilian rodents. In Brazil, 12 of the 16 genera of Oecomys are found. Oecomys bicolor is known in Brazil as the 'arboreal rat' and is, found in dry, deciduous and tropical forests. The mean body weight of Oecomys bicolor was 35.8 g and the gonadal, tubular and epithelial somatic indexes were, 0.53%, 0.47% and 0.37%, respectively. Seminiferous tubules volume density was 89.72% and the mitotic and meiotic indexes corresponded to 8.59 and 2.45 cells, respectively, and the yield of spermatogenesis was 23.83 cells. The intertubular compartment represented 10.28% of the testis parenchyma and around 5% of the interstitial space was occupied by Leydig cells, whose number per gram of testis was 11.10 × 107 cells. By evaluating the biometric and histomorphometric characteristics of the testis, there is evidence that this species has a high investment in reproduction. Due to the high contribution of the seminiferous epithelium and the intertubular compartment in this species, compared to the others of the same family, it is possible to infer that the species Oecomys bicolor has a promiscuous reproductive behaviour.

The gross reproductive morphology of the male Temminck's pangolin Smutsia temminckii (Smuts, 1832).

The Temminck's pangolin (Smutsia temminckii) is one of eight pangolin species worldwide and the only pangolin present in southern Africa. Historically, pangolins have not been able to reproduce successfully in captivity and this may be in part due to the lack of knowledge and understanding with regards to the pangolin reproductive system (anatomy, physiology, biology) in all eight species. This original study describes the gross anatomy of the male Temminck's pangolin from three adult individuals investigated. The male Temminck's pangolin presented a short, conical penis with ascrotal (internal) testes, similar to many other myrmecophagous mammals such as the aardvark (Orycteropus sp.) and anteaters (suborder: Vermilingua). However, the orientation of the penis of the Temminck's pangolin differed in that it was oriented cranioventrally, in contrast to the caudal orientation of the giant anteater. The testes were found to be bilaterally flattened with an elongate oval shape, similar to the aardvark. The specific characteristics of the reproductive tract of the male Temminck's pangolins are thought to be adaptations to their peculiar lifestyle as the male portrays characteristics that indicate adaptation to a lower basal metabolic rate and body temperature as well as to their defensive mechanism of rolling up into a ball. Our study suggests the male Temminck's pangolin reproductive anatomy is most similar and comparable to the Xenarthrans and the aardvark that display the same fossorial activities as pangolins, and the male morphology is not comparable to the phylogenetically closely-related Carnivora.

Evaluation of predictive ability of linear type gonadal traits on reproductive capacity of breeding dairy bulls.

Dimensions of linear type traits facilitate selection of livestock for breeding and rearing. To date, use of linear type traits for selection of breeding bulls is highly concentric to scrotal circumference (SC), with probable overlook to other important traits. Present study reported the importance of various gonadal linear type traits on spermatozoa production, age-related changes in gonadal linear type traits of bulls and predictive ability of these traits on bulls' reproductive potentials. Among all gonadal traits, testicular density (TD), scrotal volume (SV), paired testicular weight (PWT) and SC were found most important predictor variables in order, which can discriminate between good/poor breeding bulls, that is, produced frozen semen doses (FSD) or not. Dimensions of gonadal traits increased significantly up to 36 months age and thereafter, development became slow and negligible. In contrast, TD decreased by 30%, 51%, 64%, 68% and 71% at 12, 24, 36, 48 and >49 months age, respectively, from its base value at 6 months. Bulls of lower TD (≤0.88 g/cm3) had significantly higher ejaculate volume (+9%), sperm motility, sperm concentration (+100 million/mL) and sperm output (+26%)/ejaculate as compared to bulls of higher TD (>0.88 g/cm3). Discriminant function was developed using TD, SV, PWT and SC to identify bulls of superior reproductive potentials. It was concluded that among the investigated traits, TD was the strongest to discriminate between FSD and Non-FSD bulls. Therefore, our findings suggested that TD could be more potential trait than SC for dairy bulls' breeding soundness evaluation and assessment of reproductive ability.

Serological and histolomorphological investigation of camel bulls testes (Camelus dromedaries) during the rutting and non-rutting seasons.

BACKGROUND: Camels are bred for their milk, meat, wool and hair, transportation, and their excrement as fuel. The seasonal reproduction of camel bull is accompanied by changes in sexual activity, the morphology, and function of the testes. This study aimed to evaluate the seasonal fluctuations in serum testosterone (T) levels as well as total antioxidant capacity (TAC) and malondialdehyde (MDA) levels in the testes of dromedary bulls (Camelus dromedarius) during the rutting and non-rutting seasons. Moreover, the impact of rutting season on the testicular size and histomorphology was also observed. Seventy mature dromedary bulls were divided into a rutting group (n = 35) and a non-rutting group (n = 35). From these bulls, blood samples and testes were collected during the rutting season (October to April) and non-rutting season (May to September) from a local slaughterhouse. RESULTS: All parameters changed significantly during rutting and non-rutting periods in camel bulls. The levels of TAC in testes, and serum T were significantly (P < 0.05) higher in the rutting group than in the non-rutting group. However, testicular MDA was significantly (P < 0.05) lower in the rutting group than in the non-rutting group. TAC was negatively correlated with MDA (r = -0.59, p < 0.01). Moreover, in the rutting group and the non-rutting group, T was positively correlated with levels of TAC (r = 0.66, p < 0.0003). Additionally, testicular size (length, breadth, and thickness) was significantly greater in camels during the rutting season than in camels during the non-rutting season. Moreover, the number and diameter of seminiferous tubules, and spermatogenesis increased during the rutting season, whereas, the collagen content and apoptosis increased during the non-rutting season. CONCLUSION: This study revealed that the rutting normal breeding season (NBS, rutting group) was associated with higher levels of total antioxidant capacity (TAC), T, and spermatogenic activity while the collagen content, concentrations of MDA (the oxidative stress factor) and apoptosis (an outcome of oxidative stress) were lower than those in the low breeding season (LBS, non-rutting group). In addition, the testicular size and seminiferous tubule diameter and number were higher during the NBS.

Observations on the anatomy of the funiculus spermaticus and the testis in Brachyteles sp. (SPIX, 1823) primates - Atelidae.

BACKGROUND: Analysing the literature about the reproductive anatomy on New World Primates, one can see the need of standardisation on the description methods and, more importantly, the lack of detailed information. The problem is aggravated by the difficult access to specimens of the endangered species such as Brachyteles sp. This paper's objective was to extend knowledge on the male reproductive anatomy of these primates. The testis and funiculus spermaticus of Brachyteles are described in detail. METHODS: We utilised one individual of Brachyteles arachnoides, two hybrids (B. arachnoides × Brachyteles hypoxanthus) and photographs of the testis of a third fresh specimen of a hybrid individual. RESULTS: The septum formed by tunica dartos adheres to the testis and separates the scrotum in two testicular cavities. Passed the spermatic cord, the external spermatic fascia continues with the tunica dartos, covering the cranial half of the testis. The fascia cremasterica divides itself in bundles of fibres and forms loops around the testicles creating a sac like structure that seems to be unique among Neotropical Primates. The appendix testis is described for the first time in platyrrhini. It is presented as a sessile structure in the extremitas capitata of the testis. Previous literature on the reproductive anatomy of platyrrhini is limited. Despite that, it can be said that the large size and volume of the testis, and complex structure of the cremaster, could consist of a heat loss reduction strategy in cold and humid forest environments. CONCLUSIONS: Except for the larger size of the testicles in hybrid individuals, no other significant morphological differences were found between B. arachnoides and hybrids (B. arachnoides × B. hypoxanthus).

Corallus hortulanus testes histology: morphological and reproductive aspects.

In general snakes show differentiate anatomical, biological and behavioral particularities compared to other species. Basic information about the snakes anatomy, physiology and reproductive biology is scarce in several species, making the reproduction a challenge. Thus, the present work aims to evaluate morphological aspects of the Corallus hortulanus testes, correlating these findings with environmental factors and reproductive aspects. The testes of three specimens of Corallus hortulanus were cut to a thickness of 3µm in microtome, stained with 1% toluidine blue, photo documented and described. Seasonality was observed in the sperm production of Corallus hortulanus, with the presence of mature spermatozoa in the wettest and hottest periods of the year, as well as the largest testicular volume in these periods.

Forkhead-associated phosphopeptide binding domain 1 (FHAD1) deficiency impaired murine sperm motility.

Background: Genetic knockout-based studies conducted in mice provide a powerful means of assessing the significance of a gene for fertility. Forkhead-associated phosphopeptide binding domain 1 (FHAD1) contains a conserved FHA domain, that is present in many proteins with phospho-threonine reader activity. How FHAD1 functions in male fertility, however, remains uncertain. Methods: Fhad1-/- mice were generated by CRISPR/Cas9-mediated knockout, after which qPCR was used to evaluate changes in gene expression, with subsequent analyses of spermatogenesis and fertility. The testis phenotypes were also examined using immunofluorescence and histological staining, while sperm concentrations and motility were quantified via computer-aided sperm analysis. Cellular apoptosis was assessed using a TUNEL staining assay. Results: The Fhad1-/-mice did not exhibit any abnormal changes in fertility or testicular morphology compared to wild-type littermates. Histological analyses confirmed that the testicular morphology of both Fhad1-/-and Fhad1+/+ mice was normal, with both exhibiting intact seminiferous tubules. Relative to Fhad1+/+ mice, however, Fhad1-/-did exhibit reductions in the total and progressive motility of epididymal sperm. Analyses of meiotic division in Fhad1-/-mice also revealed higher levels of apoptotic death during the first wave of spermatogenesis. Discussion: The findings suggest that FHAD1 is involved in both meiosis and the modulation of sperm motility.

Small-bodied males invest in larger testes when highly ornamented.

Sperm competition and male mating rate are two non-mutually exclusive key evolutionary pressures selecting for larger testes within and across animal taxa. A few studies have tried to test the role of mating rate in the absence of sperm competition. Under the mating rate hypothesis, particular phenotypes of a given population that are expected to gain more mates (e.g., more ornamented males) are expected to make higher investments in testes size (a proxy for sperm production). We test this prediction in Polistes simillimus, a neotropical paper wasp in which females are single mated (no sperm competition) and males can mate with multiple partners. Testes size was predicted by body size (positive association), sexual ornamentation (negative association), and their interaction (among small males, testes size was positively related to ornamentation, but the opposite pattern was observed among large males). We propose that small-bodied well-ornamented males may face the highest risk of sperm depletion. Small-bodied males make relatively higher investment in testes size when highly ornamented. This strategy might be less profitable to large males, as they have overall larger testes. Our results provide strong evidence for the mating rate hypothesis.

Testes size seen through the glass of amphibian care.

Despite the great diversity of parental care types found in amphibians, studies linking them to post-copulatory sexually selected traits are scarce, presumably due to a lack of data. Valencia-Aguilar et al. used fieldwork and museum collections to show that paternal care appears to trade-off with testes size in glass frogs.

Measuring mantled howler monkey (Alouatta palliata) testes via parallel laser photogrammetry: Expanding the use of noninvasive methods.

Parallel laser photogrammetry (PLP), which consists of attaching two or three parallel laser beams at a known inter-beam distance to a camera, can be used to collect morphological measurements of organisms noninvasively. The lasers project onto the photo being taken, and because the inter-beam distance is known, they act as a scale for image analysis programs like ImageJ. Traditionally, this method has been used to measure larger morphological traits (e.g., limb length, crown-rump length) to serve as proxies for overall body size, whereas applications to smaller anatomical features remain limited. To that end, we used PLP to measure the testes of 18 free-living mantled howler monkeys (Alouatta palliata) at La Selva Biological Station, Costa Rica. We tested whether this method could reliably measure this relatively small and globular morphology, and whether it could detect differences among individuals. We tested reliability in three ways: within-photo (coefficient of variation [CV] = 4.7%), between-photo (CV = 5.5%), and interobserver (intraclass correlation = 0.92). We found an average volume of 36.2 cm3 and a range of 16.4-54.4 cm3, indicating variation in testes size between individuals. Furthermore, these sizes are consistent with a previous study that collected measurements by hand, suggesting that PLP is a useful method for making noninvasive measurements of testes.

Deep Learning-Based Spermatogenic Staging in Tissue Sections of Cynomolgus Macaque Testes.

The indirect assessment of adverse effects on fertility in cynomolgus monkeys requires that tissue sections of the testis be microscopically evaluated with awareness of the stage of spermatogenesis that a particular cross-section of a seminiferous tubule is in. This difficult and subjective task could very much benefit from automation. Using digital whole slide images (WSIs) from tissue sections of testis, we have developed a deep learning model that can annotate the stage of each tubule with high sensitivity, precision, and accuracy. The model was validated on six WSI using a six-stage spermatogenic classification system. Whole slide images contained an average number of 4938 seminiferous tubule cross-sections. On average, 78% of these tubules were staged with 29% in stage I-IV, 12% in stage V-VI, 4% in stage VII, 19% in stage VIII-IX, 18% in stage X-XI, and 17% in stage XII. The deep learning model supports pathologists in conducting a stage-aware evaluation of the testis. It also allows derivation of a stage-frequency map. The diagnostic value of this stage-frequency map is still unclear, as further data on its variability and relevance need to be generated for testes with spermatogenic disturbances.

Influence of photoperiod and exogenous melatonin on testis morpho-physiology of sexually mature guinea fowl (Numida meleagris).

The biological effects of simulated photoperiod and melatonin on the control of reproduction of guinea fowls (Numida meleagris) are not well understood. Herein, thirty (30) sexually mature guinea fowl cocks were randomly assigned to 1-6 groups (n = 5) and subjected to different photoperiodic regimes in the presence or absence of exogenous melatonin (Mel; 1 mg/kgBW/day, i/m) for eight weeks. Testes of the euthanized cocks were processed for gross morphology, histological, histochemical, and oxidative stress markers. Testosterone concentration was determined in serum samples using the enzyme-linked immunosorbent assay (ELISA) technique. We observed an increase in testicular size in the Mel and Non-Mel groups under long-day (LD) photoperiods, and in the Non-Mel group under short-day (SD) photoperiod. Conversely, the testicular size was drastically reduced in the Mel group for SD. Seminiferous tubules in the Mel and Non-Mel groups of the SD showed cytomorphological changes, including degenerated cells, focal vacuolations, and depletion of germinal epithelium. However, the germinal epithelium appeared to be complete and active in both the Mel and Non-Mel groups for the LD. In all groups, the testes showed positive staining for PAS with varying intensities. There was a significant difference in PAS-staining intensity between different photoperiodic regimes and exogenous melatonin. The study observed the interaction between photoperiods and exogenous melatonin on glutathione reductase (GSH), malondialdehyde (MDA), and serum testosterone. Overall, the results indicated that a long-day (LD) photoperiod, combined with exogenous melatonin, enhanced reproductive activity in male guinea fowl by increasing testicular size and serum testosterone concentration.

Reproductive tract morphology and symmetry of farmed common eland (Tragelaphus oryx) bulls, and their relationship with secondary sexual traits and social rank.

Common eland bulls are important game ranching animals in southern Africa, for tourism, breeding/live sales, trophy hunting, and game meat production. Interest has grown in their production potential, intensifying animal husbandry and breeding approaches. However, little scientific information is available regarding the intensive management of this species, including information regarding scientifically based selection criteria for breeding bulls. Often, simple phenotypic traits are utilised unless high-value game animals are being bred, with horn and body size often being the only traits considered for breeding bulls. This study provides basic information about the reproductive tract morphology, symmetry, and their relationships with secondary sexual traits, social rank, and temperament in common eland. Six eland males (2-2.5 years old; 203 ± 20 kg) were utilised for the study. Social rank, body weight and body condition score, temperament score, and horn size were determined before the animals were culled, and their reproductive tracts were collected for morphometric and histological evaluation. Results indicate relatively low asymmetry in bilateral reproductive tract components. Individual traits of eland bulls such as age, body weight, and social rank correlated the development of some testicular morphologies and thus may possibly be used in zoos, game ranching, and commercial production for the selection of breeding males, but not temperament and horn length, which should be carefully evaluated. Whilst this study provides baseline information from a limited sample size, further studies should incorporate the assessment of testicular hemodynamics, as well as the effects of factors such as season and androgen secretion patterns over a wider age range of common eland males and populations to provide further information for the management practices of breeding common eland bulls.

Inhibition of p38MAPK signalling pathway alleviates radiation-induced testicular damage through improving spermatogenesis.

BACKGROUND AND PURPOSE: Damage to the testis following exposure to ionizing radiation has become an urgent problem to be solved. Here we have investigated if inhibition of p38 mitogen-activated protein kinase (p38MAPK) signalling could alleviate radiation-induced testicular damage. EXPERIMENTAL APPROACH: In mice exposed to whole body radiation (2-6 Gy), morphological changes of the epididymis and testis was measured by histochemical staining. immunohistochemical and immunofluorescence procedures and western blotting were used to monitor expression and cellular location of proteins. Expression of genes was assessed by qPCR and RNA-Seq was used to profile gene expression. KEY RESULTS: Exposure to ionizing radiation induced dose-dependent damage to mouse testis. The sperm quality decreased at 6 and 8 weeks after 6 Gy X-ray radiation. Radiation decreased PLZF+ cells and increased SOX9+ cells, and affected the expression of 969 genes, compared with data from non-irradiated mice. Expression of genes related to p38MAPK were enriched by GO analysis and were increased in the irradiated testis, and confirmed by qPCR. Levels of phospho-p38MAPK protein increased at 28 days after irradiation. In irradiated mice, SB203580 treatment increased spermatozoa, SOX9+ cells, the area and diameter of seminiferous tubules, sperm movement rate and density. Furthermore, SB203580 treatment increased SCP3+ cells, accelerating the process of spermatogenesis. CONCLUSION AND IMPLICATIONS: Exposure to ionizing radiation clearly changed gene expression in mouse testis, involving activation of p38MAPK signalling pathways. Inhibition of p38MAPK by SB203580 partly alleviated the testicular damage caused by radiation and accelerated the recovery of sperms through promoting spermatogenesis.

Field Morphology and Interpretation.

Semen morphology evaluation in the field should always be performed at 1000× with oil immersion. The development of a spermiogram will aid the practitioner to interpret potential fertility of semen at the time of sampling as well as determine potential causes of an abnormal spermiogram. Bulls, which experience stress or impairment of thermoregulation of the testes for any reason, often experience a transitory decrease in the quality of sperm morphology. This can be recognized by a sequence of appearances of morphologic defects coupled with a thorough patient history.

Antifertility effects of quinestrol in male lesser bandicoot rat, Bandicota bengalensis, and potential in managing rodent population under field conditions.

Integrating fertility control techniques using steroid hormones after lethal control can help reduce post control rebuildup of rodent populations. The current study is the first to assess the antifertility effects of quinestrol in male lesser bandicoot rat, Bandicota bengalensis which is the predominant rodent pest species in Southeast Asia. Rats in different groups were fed bait containing 0.00%, 0.01%, 0.02%, and 0.03% quinestrol for 10 days in laboratory and evaluated immediately, and 15, 30, and 60 days after treatment discontinuation for effect on reproduction and other antifertility parameters. Effect of 0.03% quinestrol treatment for 15 days was also observed in managing rodent populations in groundnut crop fields. Treatment resulted in average consumption of 19.53 ± 1.80, 67.63 ± 5.50, and 246.67 ± 1.78 mg/kg bwt active ingredient by three treated groups of rats, respectively. No reproduction was observed in female rats mated with male rats treated with 0.03% quinestrol, even 30 days after cessation of treatment. Post-mortem examination showed a significant (P < 0.0001) effect of treatment on organ weights (testis, cauda epididymis, seminal vesicles, and prostate gland) and different sperm parameters (sperm motility, sperm viability, sperm count, and sperm abnormality) in the cauda epididymal fluid with partial reversibility after 60 days. A significant (P < 0.0001) effect of quinestrol on the histomorphology of testis and cauda epididymis was observed, suggesting its effect on spermatogenesis. Affected cell association and cell count in seminiferous tubules did not fully recover within 60 days of stopping treatment. Evaluation of the effects of quinestrol treatment in groundnut fields showed greater reductions in rodent activity in fields treated with 2% zinc phosphide followed by 0.03% quinestrol treatment as compared to fields treated with 2% zinc phosphide alone. Research concludes that quinestrol has the potential to reduce fecundity and post control rebuildup of B. bengalensis populations, but long-term studies of the effectiveness of quinestrol under large-scale field conditions are needed to use it as part of an integrated pest control program for rodents.

Hormone measurements and histomorphological observations in male Bactrian camels.

The aim of this study was to investigate the effect of age on the hypothalamic-pituitary-gonadal (HPG) axis hormones and to determine the morphological changes of the testis. The Bactrian camels were divided into two groups based on their ages. The results showed that the testicular weight was significantly heavier in adult male camels than in pubertal male camels (P < 0.05). There were also significant differences between testicular length, testicular width, and testicular volume (P < 0.05). In the testes of both pubertal and adult male camels, Sertoli cells, spermatogonia, spermatocytes, round spermatids, and elongated spermatids were observed. Adult male camels had more Sertoli cells (P < 0.01) and elongated spermatids (P < 0.05). The concentrations of testosterone, follicle-stimulating hormone (FSH), and luteinizing hormone (LH) were higher in the plasma and testes of adult camels than in pubertal camels (P < 0.05). E2 concentrations were lower in adult camels than in pubertal camels (P < 0.05). The testosterone levels in testicular tissue were higher than in blood plasma in both adult and pubertal stage (P < 0.05). In conclusion, these findings provide supportive knowledge and show the significant differences in terms of testicular volume, testicular hormone concentrations, and testicular morphology between different developmental stages in Bactrian camels.

Andrology of shortnose guitarfish Zapteryx brevirostris (Müller & Henle, 1841) (Chondrichthyes, Trygonorrhinidae).

The andrological study of a species involves the macro- and microscopic analyses of the internal reproductive organs and the evaluation of seminal parameters and ultrastructural characteristics of the spermatozoa. As in other vertebrates, the male reproductive tract in chondrichthyans consists of testes and reproductive ducts (efferent duct, epididymis, Leydig's gland, ductus deferens and seminal vesicle). In this study the authors used three adult specimens of Zapteryx brevirostris from wild capture kept at the Ubatuba Aquarium, Brazil. Semen was collected by abdominal massage over the location of the seminal vesicle, preceded by ultrasonographic evaluation. The semen collected was diluted 1:200 and subject to quantitative and morphological analyses. Ultrastructural analysis was performed using transmission and scanning electron microscopy. Correlation was observed between successful collection and ultrasonographic image of an engorged seminal vesicle, as well as testicles with easily delimitable margins and higher echogenicity. It was possible to identify free spermatozoa with helical filiform appearance, as well as spermatozeugmata. The average sperm concentration resulted in 5 million packets per millilitre and 140 million spermatozoa per millilitre. The sperm nucleus is described as follows: cone shaped, parachromatin sheath less dense than the chromatin of the nucleus, smooth depression of the nuclear fossa, abaxial axoneme 9 + 2 and accessory axonemal columns in positions 3 and 8 and oval shaped, with flattened inner surface in cross-section. These results broaden the knowledge of the andrology of this species, contributing to ex situ breeding programmes.