Embryonic development of the scorpion mud turtle (Kinosternon scorpioides) bred in captivity.

Background: The developmental biology of Kinosternon scorpioides is described, based on the phenotype. This species is important for the flora because they are excellent seed disseminators. In addition, basic embryological information is not yet fully clarified, and this research provides unprecedented information on the chelonian embryology of the Amazonian fauna. Aim: The present study aims to identify the embryology of K. scorpioides in captivity during different periods. Methods: Females were monitored throughout the reproductive cycle, by video monitoring, to identify nests and the presence of newly laid eggs. At regular weekly intervals, embryo samples were collected fixed in a 4% paraformol solution and preserved in 70% alcohol. For the embryonic characterization, we used a stereomicroscope and the scanning electron microscopy method. Results: We describe 15 embryonic stages for a 15-week (105-day) incubation process. Only at 42 days (6th week) was the morphological characterization of a chelonian observed and at the 12th week (Stage XII), the phenotypic characterization of the species K. scorpioides. Conclusion: In view of the evidence, we found that these phases are similar to the other turtles, with structural variations in the appearance and disappearance of structures due to the specific characteristics of the species.

Two new species of Diaphorocleidus and new data on D. affinis (Monogenoidea: Dactylogyridae) parasitizing Bryconops cf. affinis (Characiformes: Iguanodectidae) from the Munim River basin, State of Maranho, northeastern Brazil.

During a study conducted on the helminth fauna of fishes in the middle Munim River basin, State of Maranho, northeastern Brazil, three species (two new) of Diaphorocleidus Jogunoori, Kritsky & Venkatanarasaiah, 2004 are reported from the gills of the piaba Bryconops cf. affinis (Iguanodectidae): Diaphorocleidus affinis (Mizelle, Kritsky & Crane, 1968), D. forcipiformis n. sp. and D. munimensis n. sp. New morphological data, drawings, and geographic distribution were provided for D. affinis. Diaphorocleidus forcipiformis n. sp. is characterized by a male copulatory organ with 2 rings counterclockwise and base forming a small tube with two circular flanges and accessory piece bifurcated, claw-shaped, with parts similar in shape and size, one of them distally bifid. Diaphorocleidus munimensis n. sp. is differentiated by the accessory piece, which is composed of two large pieces, united in their proximal part, claw-shaped, and distally hooked. The findings of this initial survey on the helminth parasites of fishes in this area emphasize the importance of carrying out comparable surveys on other fish species. Such surveys may lead to the identification of unknown species or new occurrences.

Assessment of Essential and Potentially Toxic Elements in Water and Sediment and the Tissues of Sciaena deliciosa (Tschudi, 1846) from the Coast of Callao Bay, Peru.

The lorna drum Sciaena deliciosa is a coastal demersal species and one of the underlying artisanal fisheries in some areas of Peru, and is also a source of protein for Peruvian coastal dwellers. The investigation addresses concern about the environmental impact on this fish species and the potential risks to human health through the consumption of contaminated seafood. This research endeavors to assess the concentration of potentially toxic and essential elements in the muscle and liver tissues of S. deliciosa, in addition to the presence thereof in water and sediment capture areas on the coast of Callao, Peru. The study revealed that, in water samples, Ag, Ni, and Zn exceed Peruvian standards, but were below international standards, and Ba, P, Se, and Sn exceed international standards. In the sediments, As, Cd, Pb, Fe, and Zn were above international standards. In the fish, S. delicious muscle demonstrated As, Hg, and Pb exceeding at least one international standard. In the liver, As, Hg, Pb, and Cu exceed international standards. The study approach increased accuracy in risk assessments, offering crucial insights into the interplay between heavy metal pollution, water quality, and animal health, informing risk management strategies. Future studies can explore the long-term effects of heavy metal exposure on different organisms and consider their cumulative impact on health.

New and previously described species of Ameloblastella (Monogenoidea: Dactylogyridae) parasitizing Hypophthalmus marginatus and Pimelodina flavipinnis (Siluriformes: Pimelodidae) from the Tocantins River, Maranhão State, Brazil.

A new and two previously described species of Ameloblastella Kritsky, Mendoza-Franco & Scholz, 2000 were found in the gills of two pimelodid catfishes from the Tocantins River, Maranhão State, Brazil: Ameloblastella prima n. sp. from Pimelodina flavipinnis Steindachner, and A. edentensis Mendoza-Franco, Mendoza-Palmero & Scholz, 2016 and A. peruensis Mendoza-Franco, Mendoza-Palmero & Scholz, 2016 from Hypophthalmus marginatus Valenciennes. The new species differs from its congeners by having an accessory piece tubular, covered by a delicate membranous cap at 2/3 of the length, by the shape of the ventral and dorsal anchors, in which the ventral anchor is represented by a curved shaft in a position of 80° degrees, with delicate ornamentations located at the superficial and deep root areas, and the dorsal anchor with a long, well-developed and convex superficial root and short deep root, also presenting delicate ornamentations at the superficial and deep root areas. The present study provides new biogeographical data on the two previously described species of Ameloblastella and improves the knowledge on the species of Monogenoidea from the Neotropical Region, increasing to 14 the number of known species of Ameloblastella for this region.

Two new species of Curvianchoratus (Monogenoidea, Dactylogyridae) parasitizing Psectrogasteramazonica (Characiformes, Curimatidae) and a new record for Curvianchoratussingularis in the Tocantins River, Maranhão, Brazil.

Several studies have demonstrated parasitism by monogenoids in characiform fish in the Neotropics. During studies on the helminth fauna of curimatids from the Tocantins River, specimens of Psectrogasteramazonica Eigenmann & Eigenmann, 1889 were examined and species of Curvianchoratus Hanek, Molnar & Fernando, 1974 were found. Species of the genus are characterized mainly by the complex shape of haptoral anchors with a modified dorsal anchor, composed by two subunits, dorsal-median and dorsal. To date, two species of Curvianchoratus are known to parasitize curimatid fishes: the type species Curvianchoratushexacleidus Hanek, Molnar & Fernando, 1974 and Curvianchoratussingularis (Suriano, 1980). During examination of specimens of P.amazonica collected in the Tocantins River, Embiral, Imperatriz, Maranhão State, Brazil, two new species of Curvianchoratus were found and are described herein. Curvianchoratuspsectrogasterisp. nov. and Curvianchoratusdominguesisp. nov. are characterized by possessing the male copulatory organ formed by a long cirrus and a claw-shaped accessory piece, connected to the base of the male copulatory organ by a ligament. The new species differs from the two known congeneric species mainly by the morphology of the dorsal-median and dorsal subunits of the dorsal anchor. Curvianchoratuspsectrogasterisp. nov. also differs from other species of the genus by the absence of the ventral bar and Curvianchoratusdominguesisp. nov. by the size and shape of the ventral bar. An amendment to the diagnosis of Curvianchoratus is provided to accommodate the new species. The present study increases the number of Curvianchoratus species to four and extends the occurrence of the genus to the Tocantins-Araguaia Basin.

New host record and geographical distribution of Nematoda parasitizing Hypophthalmus marginatus Valenciennes (Siluriformes) from the Tocantins River, Brazil

Hypophthalmus marginatus is among the most commercialized fish from the Amazon region, with fish fillets exported to Southeastern Brazil and other countries. In the present study, the H. marginatusanalyzed were parasitized by third-stage larvae of Hysterothylaciumsp. and Anisakissp. These nematodes are being reported for the first time in H. marginatus collected from the Tocantins River, representing a new host and geographical records, and expanding knowledge of the hosts of these nematodes in the Neotropical Region. A brief description with original measurements is presented.

Skin development in 14 to 60-day-old Guinea pig fetus / Desarrollo de la piel del feto de conejillo de indias de 14 a 60 días

To contribute knowledge of an important experimental model for studies on skin embryology, a study was carried out to describe the morphological events of the skin during the intrauterine life of Cavia porcellus from the 10th to the 60th day of gestation. Embryos and fetuses were dissected, and the skin of the nasal, cranial, lumbar and anal regions was processed byoptical microscopy. At 30 days the first hairs, called lanugos, were observed in the cranial region. The morphological description showed that a few days can make a great difference in development.

Con el objetivo de contribuir al conocimiento de un importante modelo experimental para estudios sobre embriología de la piel, se llevó a cabo un estudio para describir los eventos morfológicos de la piel durante la vida intrauterina de Cavia porcellus desde el día 10 hasta el día 60 de gestación. Los embriones y los fetos se disecaron y se procesó la piel de las regiones nasal, craneal, lumbar y anal, mediante microscopía óptica. A los 30 días se observaron los primeros vellos, llamados lanugos, en la región craneal. La descripción morfológica mostró que unos pocos días pueden marcar una gran diferencia en el desarrollo.

Immunolocalization of steroidogenic enzymes in the vaginal mucous of Galea spixii during the estrous cycle.

BACKGROUND: The synthesis of sex steroids is controlled by several enzymes such as17α-hydroxylase cytochrome P450 (P450c17) catalyzing androgen synthesis and aromatase cytochrome P450 (P450arom) catalyzing estrogen synthesis, both of which must complex with the redox partner NADPH-cytochrome P450 oxidoreductase (CPR) for activity. Previous studies have identified expression of steroidogenic enzymes in vaginal tissue, suggesting local sex steroid synthesis. The current studies investigate P450c17, P450aromatase and CPR expression in vaginal mucosa of Galea spixii (Spix cavy) by immuno-histochemical and western immunoblot analyses. METHODS: Stages of estrous cyclicity were monitored by vaginal exfoliative cytology. After euthanasia, vaginal tissues were retrieved, fixed and frozen at diestrus, proestrus, estrus and metestrus. The ovaries and testis were used as positive control tissues for immunohistochemistry. RESULTS: Data from cytological study allowed identification of different estrous cycle phases. Immunohistochemical analysis showed different sites of expression of steroidogenic enzymes along with tissue response throughout different phases of the estrous cycle. However, further studies are needed to characterize the derived hormones synthesized by, and the enzymes activities associated with, vaginal tissues. CONCLUSION: Current results not only support the expression of enzymes involved in sex steroid synthesis in the wall of the vagina, they also indicate that expression changes with the stage of the cycle, both the levels and types of cells exhibiting expression. Thus, changes in proliferation of vaginal epithelial cells and the differentiation of the mucosa may be influenced by local steroid synthesis as well as circulating androgens and estrogens.

Follicular development and morphological changes in the vaginal epithelium during the estrous cycle of Galea spixii.

The current study aimed to determine if characteristics observed in vaginal cytology during the estrous cycle of female SYT cavies corresponded with proliferation of the vaginal epithelium, characterized by proliferating cell nuclear antigen (PCNA) immunolocalization, and with follicular development at different phases of the estrous cycle. After determining estrous cycle phases by vaginal cytology, females were euthanized at metestrus, diestrus, proestrus, and estrus. Histological study of the vaginal epithelium and ovary were then performed. Immunohistochemistry for PCNA in vaginal tissue at each cycle phase was also performed. Superficial cornified cells and early post-ovulatory follicles were found at estrus. Few nuclei below the enucleate superficial cells were immunoreactive to PCNA. At metestrus, the vaginal epithelium underwent desquamation and lost the superficial cornified cells; basal and intermediate cells appeared, and the post-ovulatory follicle formed an early corpus luteum. No PCNA immunoreactivity was observed. At diestrus, the corpus luteum was developed, and the vaginal epithelium contained basal and intermediate cells. There was PCNA immunoreactivity in the cellular nucleus in the germinative stratum of the epithelium. Because of the growth and maturation of ovarian follicles, the vaginal epithelium suffered intense proliferation at proestrus. Vaginal cytology revealed large intermediate cells and nucleated and enucleated superficial cornified cells. In the ovary, mature follicles were present. More apparent immunoreactivity of PCNA in the germinative layer was found. In summary, we inferred that vaginal exfoliative findings matched the proliferation process of the vaginal epithelium. PCNA immunolocalization occurred as well as corresponding follicular development in the ovaries.

Morphology of the adrenal glands of giant anteater (Myrmecophaga tridactyla, Linnaeus, 1758) of wild life / Morfologia das glândulas adrenais de tamanduá-bandeira (Myrmecophaga tridactyla, Linnaeus, 1758) de vida livre

The Myrmecophaga tridactyla (family Pilosa), popularly known in Brazil as the giant anteater is classified as an endangered species by the main survey agencies of biodiversity preservation around the world. The adrenal glands are important organs, which are related to homeostasis of the animal. This study aimed to describe the morphology of the adrenal glands of M. tridactyla, providing data for future studies related to the production of steroid hormones in specimens exposed to different stress factors. The adrenal glands of 14 specimens were used. The glands were measured, photodocumented and described by light microscopy. The adrenals were positioned in the cranial extremity of the kidneys (left and right) and related medially to the caudal vena cava. The right adrenal gland had an elongated shape while the left adrenal gland had pyramidal or triangular shape. The weight was 4.765±0.129g for the right adrenal and 3.975±0.213g for the left adrenal. The length was 4.50±0.14cm for the right adrenal and 4.28±0.11cm for the left adrenal. The width was 2.60±0.13cm for the right adrenal and 2.37±0.12cm for the left adrenal. The thickness was 0.45±0.11cm for the right adrenal and 0.68±0.14cm for the left adrenal. Statistical differences (p<0.05) between right and left adrenals for all values analyzed were observed. Microscopically it was observed a capsule composed by modeled dense connective tissue lining the organ. Below this capsule, from the outermost to the innermost layer, it was observed a cortical region divided into glomerular, fasciculata and reticular zones with a medullar region occupying the center of the organ. Further studies related to steroidogenesis with specimens collected at different periods of the year are necessary, aiming to observe if there are morphological or hormonal variations in the adrenal glands due to seasonal periods. This information would be of great importance because it could reflect the behavioral habits of this species.

O Myrmecophaga tridactyla (família Pilosa), conhecido popularmente no Brasil como Tamanduá- Bandeira, é uma espécie classificada como ameaçada de extinção pelos principais órgãos de levantamento e preservação da biodiversidade no mundo. As glândulas adrenais são importantes órgãos, relacionados com a homeostasia dos animais. Neste estudo, objetivou-se descrever a morfologia das glândulas adrenais de M. tridactyla, fornecendo dados para futuros estudos relacionados à produção de hormônios esteroides em espécimes expostos a diferentes fatores de stress. Esta pesquisa traz a análise das glândulas adrenais em 14 espécimes de M. tridactyla, as quais foram mensuradas, fotodocumentadas, processadas e analisadas por microscopia de luz. Encontrou-se que as glândulas adrenais pares estavam posicionadas na extremidade cranial dos rins e relacionadas medialmente com a veia cava caudal. Sendo que, a glândula adrenal direita possuía formato mais alongado que a glândula adrenal esquerda, a qual apresentou formato piramidal ou triangular. A massa da glândula adrenal direita foi de 4,765±0,129g, enquanto a esquerda pesou 3,975±0,213g. O comprimento foi de 4,50±0,14cm para a glândula direita e 4,28±0,11cm para a esquerda. A largura foi de 2,60±0,13cm para a glândula direita e 2,37±0,12cm para a esquerda. A espessura da glândula direita foi de 0,45±0,11cm e da esquerda foi 0,68±0,14. Foram observadas diferenças estatísticas (p<0,05) entre as glândulas direitas e esquerdas em todas as dimensões analisadas. Com auxílio de microscopia de luz observou-se uma cápsula de tecido conjuntivo denso modelado, revestindo o órgão. Abaixo dessa cápsula, foi possível evidenciar, da camada mais externa para a mais interna, uma região cortical, dividida em zonas glomerular, fasciculada e reticular, com uma região medular ocupando o centro do órgão. Futuros estudos relacionados à esteroidogênese adrenal com espécimes em diferentes épocas do ano poderiam demonstrar se as glândulas adrenais apresentam variações sazonais em sua conformação morfológica ou na produção de hormônios adrenais decorrentes dessas variações, sendo que, estes dados seriam de grande importância, pois poderiam refletir os hábitos comportamentais nesta espécie.

Development of the central nervous system in guinea pig (Cavia porcellus, Rodentia, Caviidae) / Desenvolvimento do sistema nervoso central em guinea pig (Cavia porcellus, Rodentia, Caviidae)

This study describes the development of the central nervous system in guinea pigs from 12th day post conception (dpc) until birth. Totally, 41 embryos and fetuses were analyzed macroscopically and by means of light and electron microscopy. The neural tube closure was observed at day 14 and the development of the spinal cord and differentiation of the primitive central nervous system vesicles was on 20th dpc. Histologically, undifferentiated brain tissue was observed as a mass of mesenchymal tissue between 18th and 20th dpc, and at 25th dpc the tissue within the medullary canal had higher density. On day 30 the brain tissue was differentiated on day 30 and the spinal cord filling throughout the spinal canal, period from which it was possible to observe cerebral and cerebellar stratums. At day 45 intumescences were visualized and cerebral hemispheres were divided, with a clear division between white and gray matter in brain and cerebellum. Median sulcus of the dorsal spinal cord and the cauda equina were only evident on day 50. There were no significant structural differences in fetuses of 50 and 60 dpc, and animals at term were all lissencephalic. In conclusion, morphological studies of the nervous system in guinea pig can provide important information for clinical studies in humans, due to its high degree of neurological maturity in relation to its short gestation period, what can provide a good tool for neurological studies.(AU)

Este estudo descreve o desenvolvimento do sistema nervoso central em guinea pig do 12º dia pós-concepção (dpc) até ao nascimento. No total, 41 embriões e fetos foram analisados macroscopicamente e por microscopia de luz e eletrônica. O fechamento do tubo neural foi observado no dia 14 e o desenvolvimento da medula espinhal e diferenciação das vesículas primitivas do sistema nervoso central foram observados no dia 20. Histologicamente, o tecido cerebral indiferenciado foi observado como uma massa de tecido mesenquimal entre os dias 18 e 20 e no 25º dia o tecido no interior do canal medular apresentou maior densidade. No dia 30 o tecido cerebral apresentou-se diferenciado, período no qual a medula espinhal preenchia todo o canal vertebral e foi possível observar os estratos cerebral e cerebelar. No dia 45 as intumescências cervical e lombar foram visualizadas e os hemisférios cerebrais estavam divididos, com uma clara distinção entre substância branca e cinzenta no cérebro e cerebelo. O sulco mediano dorsal da medula espinhal e a cauda equina foram evidentes apenas no dia 50. Não houve diferenças estruturais significativas em fetos de 50 e 60 dpc e animais a termo eram todos lisencefálicos. Estudos morfológicos do sistema nervoso em guinea pig podem fornecer informações importantes para estudos clínicos em seres humanos devido ao alto grau de maturidade neurológica em relação ao seu período de gestação curto, fato que servir como excelente ferramenta em estudos neurológicos.(AU)

Lumbosacral plexus of the mongolian gerbil(Meriones unguiculatus Milne-Edwards, 1867) / Plexo lombossacral do gerbil (Meriones unguiculatus Milne-Edwards, 1867)

The Mongolian gerbil, belonging to the Muridae family, is characterized as an economic asset in the pet market due to its easy management. Current research analyzes and describes the origin of the nerves that make up the lumbosacral plexus in the species, foregrounding comparative anatomy, especially among wild rodents. The experiment, approved by the Committee of Institutional Bioethics, involved 15 animals which had been used in other studies and were donated to the Laboratory of Applied Animal Morphophysiology of the Federal Rural University of the Semi-Arid, Mossoró, Rio Grande do Norte, Brazil. The animals were fixed in a water solution of formaldehyde 10%. After 72 hours, they were dissected, the abdominal cavity was opened and eviscerated, and the psoas minor, psoas major and the quadratus lumborum muscles were removed to inspect the nerves that form the lumbosacral plexus. Results were given in percentages and grouped in tables. The lumbosacral plexus of the Mongolian gerbil frequently derived from the ventral roots of the last thorax nerves, from the seven lumbar nerves and from the four sacral nerves (Type II ­ T12-S4). The nerves of the gerbil´s lumbosacral plexus are the iliohypogastricus, ilioinguinalis, cutaneus femoris lateralis, genitofemoralis, femoralis, obturatorius, ischiadicus, gluteus cranialis, pudendus, gluteus caudalis and rectales caudales nerves. Information on the origin of the nerves of the gerbil´s lumbosacral plexus and their description is relevant for clinical and surgical studies, and for the application of techniques or anesthetic drugs.

O esquilo da Mongólia é um roedor pertencente à família Muridae, caracterizado por seu interesse econômico no mercado pet e por ser de fácil manejo. Esta pesquisa analisa e descreve a origem dos nervos que formam o plexo lombossacral da espécie. No experimento foram utilizados 15 animais, provenientes de outros estudos aprovados pelo Comitê de Bioética Institucional, que foram doados ao Laboratório de Morfofisiologia Animal Aplicada da Universidade Federal Rural do Semi-Árido, Mossoró, Rio Grande do Norte. Os animais foram fixados em solução aquosa de formaldeído a 10%. Após 72 horas, os animais foram dissecados, realizando-se a abertura da cavidade abdominal, depois, eviscerados e em seguida, os músculos psoas maior, psoas menor e quadrado lombar foram removidos para visualização dos nervos que formam o plexo lombossacral. Os resultados foram expressos em percentagens e agrupados em tabelas. O plexo lombossacral do gerbil originou-se mais frequentemente das raízes ventrais do último nervo torácico, dos sete nervos lombares e dos quatro nervos sacrais (Tipo II ­ T12-S4). Os nervos que formaram o plexo lombossacral do gerbil foram: ílio-hipogástrico, ílioinguinal, cutâneo femoral lateral, genitofemoral, femoral, obturatório, isquiático, glúteo cranial, pudendo, glúteo caudal, e nervo retal caudal. O conhecimento sobre a origem e os nervos do plexo lombossacral no gerbil mostra-se útil para estudos clínico-cirúrgicos e aplicação de técnicas ou fármacos anestésicos.

Development and morphological changes in the vaginal closure membrane throughout gestation in Galea spixii (Rodentia: Caviidae).

Present research was carried out in order to perform the monitoring of development, recognizes the type of tissue and describes histological and cellular changes of the vaginal closure membrane (VCM) throughout pregnancy in Galea spixii. The results showed that at 20 days of gestation (DG), the VCM occludes completely the external vaginal ostium. Microscopically, the VCM presented juxtaposed cells, derived from the stratum germinative of the stratified epithelium of vaginal mucosa at 20 DG and areas with cell clusters with the presence of intercellular spaces in the final stages of pregnancy (40-50 DG). At 0 DG, the stratified epithelium of vaginal mucosa presented all strata but at 20 DG presented stratified epithelium without the stratum corneum and stratum granular and showed communicant junctions by desmosomes and interdigitations in the cell membrane compound the VCM. Gradually from 40 to 50 DG the stratum germinative became barely perceptible. Many cells showed apoptotic nuclei and emerged many intercellular spacing. So, the interdigitations and desmosomes were not observed. Here, it was demonstrated for the first time that the VCM is formed after the extinction of the stratum granular and corneum of the vaginal mucosa epithelium, with the proliferation of the cells of stratum germinative and communication and junction through desmosomes and interdigitations of these cells. At the end of pregnancy, cellular apoptosis; the spread of stratum germinative; and, absence of cellular communication and junction may be responsible for the weakening of the VCM and may assist the process of rupture of this membrane.

Morphological characteristics of the tongue of the rock cavy- Kerodon rupestris wied, 1820 (Rodentia, caviidae) / Características morfológicas da língua em mocós- Kerodon rupestris wied, 1820 (Rodentia, caviidae)

The Kerodon rupestris are wild rodents bred in captivity in order to their conservation and development of researches. The aim of this study was describe the morphology of the tongue from eight animals by light microscopy and scanning electron microscopy, beyond macroscopic studies. The tongues of K. rupestris had 3.15 ± 0.28 cm of length; 1.0 ± 0.20 cm width at the root; 0.38 ± 0.10 cm width at the body; and, 1.10 ± 0.09 cm width at the apex. Thickness measurements were 0.50 ± 0.09 cm at the apex; 0.30 ± 0.10 cm at the body; and, 0.70 ± 0.10 cm at the root. The free apex had 0.50 ± 0.10 cm in length. The dorsal surface of the tongue contained the fungiform and filiform papillae at the apex and body; conical papillae and a pairs of vallate papillae at the root, and foliated papillae dorsolaterally positioned in the root region. The proper lamina of the dorsal surface of the tongue was composed by keratinized stratified squamous epithelium, in which lingual papillae were found; and, a rich network of skeletal striated muscle and non-modeled dense connective tissue, in which vessels, nerves, mucous and serous acini and their respective ducts were found. In summary, dorsal surface of the tongue of K. rupestris had filiform and conical papillae with mechanical function, and, fungiform, vallate and foliated papillae with taste buds responsible by gustatory function. Moreover, the tongue of these animals showed some peculiarities as the eminence on the apex in sagittal plane, which needs further studies.

Os Kerodon rupestris são roedores silvestres criados em cativeiro para sua conservação e desenvolvimento de pesquisas. O objetivo deste estudo foi descrever a língua destes animais por meio de microscopia de luz, microscopia eletrônica de varredura e estudos macroscópicos. As línguas de K. rupestris tinham 3,15 ± 0,28 cm de comprimento; 1,00 ± 0,20 cm de largura na raiz, 0,38 ± 0,10 cm de largura no corpo e 1,10 ± 0,09 de largura no ápice. As medidas de espessura foram 0,50 ± 0,09 cm no ápice, 0,30 ± 0,10 cm no corpo e 0,70 ± 0,10 cm na raíz. O ápice livre possuía 0,50 ± 0,10 cm de comprimento. A superfície dorsal da língua continha papilas fungiformes e filiformes no ápice e corpo; papilas cônicas e um par de papilas valadas na raiz; e, papilas foliadas posicionadas dorsolateralmente na região da raiz. A lâmina própria da superfície dorsal da língua estava composta por epitélio estratificado pavimentoso queratinizado, no qual as papilas linguais foram encontradas; e, uma rica rede de músculo estriado esquelético e tecido conjuntivo denso não modelado, no qual veias, nervos e ácinos serosos e mucosos e seus respectivos ductos foram encontrados. Em conclusão, a superfície da língua de K. rupestris apresentou papilas filiformes e cônicas com função mecânica e papilas fungiformes, valadas e foliadas com botões gustativos responsáveis pela função gustativa. Além disso, a língua desses animais apresentou ainda particularidades, como uma eminência no plano sagital do ápice que necessita de futuros estudos.

Intrauterine sexual differentiation: biosyntesis and action of sexual steroid hormones

The objective of this review was to describe sexual differentiation events in mammals, relating them to biosynthesis of sexual steroid hormones and their mechanisms of action. Cholesterol is the precursor of sexual steroid hormone biosynthesis via action of several enzymes converting these hormones. Progestagens hormones serve as substrate for the production of androgens, which in turn serve as substrate for estrogen hormones. These hormones are responsible for sexual differentiation and reproductive cycles of mammals. Sexual differentiation process comprises determining the sexual chromosomes XX or XY + SRY and other genes linked to them, differentiation of gonads in testis or ovary, differentiation of internal and external male or female genital organs from undifferentiated anatomical structures present in the embryo, which is dependent on the presence or absence of testes and the production of anti-Müllerian hormone and testosterone; and secondary sexual differentiation, which is the response of various tissues to hormones produced by the gonads, interacting with genes linked to sexual chromosomes to increase or decrease the differences in sexual phenotype. However, some differences between the sexes and some anomalies of sexual differentiation are not explained only by these sexual hormonal effects, but also by the effect of genes encoded in sexual chromosomes.

The morphology of female genitalia in Galea spixii (Caviidae, Caviinae) / Morfologia da genitalia feminina em Galea spixii (Caviidae, Caviinae)

The yellow-toothed cavy (Galea spixii) is a hystricomorph rodent of the Caviidae family. In Brazil, G. spixii are bred in captivity to provide an alternative protein source and to preserve the species. However, there is a lack of data on the animal´s female genital organs. Current research describes the morphology of the species´s adult female genital organs, regardless of the stage of its estrous cycle, and permits basic knowledge on its anatomy that will be a help for future projects in reproduction in captivity. Adult female genital organs of G. spixii comprise two ovaries with follicles at several developmental stages; uterine tubes whose epithelium and muscular layer thickness modify themselves throughout the isthmus, ampulla and infundibulum regions; double uterus and uterine horns with uterine glands that open to a single cervix which is linked to the vagina by the fornix; a variegated vaginal epithelium from different animals; a vulva with a clitoris trespassed by the urethra which features a lack of vaginal vestibule and the presence of a vaginal closure membrane. The morphology of G. spixii female genitalia has interesting characteristics such as the vaginal closure membrane and a clitoris trespassed by urethra that needs further studies. Other investigations on developmental biology could demonstrate a possible intrauterine masculinization in the G. spixii female.

O preá silvestre do semiárido (Galea spixii) é um roedor histricomorfo da família Caviidae. No Brasil, G. spixii são criados em cativeiro com intuito de gerar uma fonte alternativa de proteína e preservar a espécie. Embora, existam poucos dados sobre os órgãos genitais femininos destes animais. A presente pesquisa descreve a morfologia dos órgãos genitais femininos de G. spixii adultas, sem considerar as fases do ciclo estral e permite conhecimento básico sobre a anatomia que poderá ajudar futuros projetos de reprodução em cativeiro. Os órgãos genitais femininos de G. spixii adultas compreendem dois ovários com folículos em diversos estados de desenvolvimento; tubas uterinas, cujo epitélio e camada muscular se modificam ao longo das regiões do istmo, ampola e infundíbulo; útero duplo e dois cornos uterinos com glândulas, os quais se abrem em uma única cérvix, a qual se conecta com a vagina pelo fórnix; uma vagina com epitélio variado entre diferentes animais; uma vulva com clitóris transpassado pela uretra; ausência de vestíbulo vaginal e a presença de uma membrana de oclusão vaginal. A morfologia da genitália feminina de G. spixii possui interessantes características como a membrana de oclusão vaginal e um clitóris transpassado pela uretra, as quais necessitam de maiores estudos. Outras pesquisas sobre biologia do desenvolvimento poderiam demonstrar uma possível masculinização intrauterina das fêmeas de G. spixii.

Body and testicular biometric parameters of the scorpion mud turtle (Kinosternon scorpioides) / Parâmetros biométricos corporais e testiculares de tartaruga (Kinosternon scorpioides)

The reptile Kinosternon scorpioides is a freshwater chelonian, popularly known as jurará, and is found in the Baixada Maranhense, Maranhão State, Brazil. Due to the lack of scientific information on the reproductive biology of the species, current paper describes the body and testicular biometry and the gonad -somatic index (GSI) in adult specimens collected from the natural environment. Twenty male adults were collected in the rainy (n = 10) and dry (n = 10) seasons. Data were derived from the body, testis size and GSI and tests of correlation between these measures were performed. The body biometrics of free-living Kinosternon scorpioides is similar to those found in other studies for adult animals bred in captivity. The body weight was higher in animals collected in the rainy season than that in animals collected in the dry season. The testis size presents variations among animals captured during the rainy and dry season, but the gonadossomatic index did not vary between different groups of animals. Further studies were suggested related to the levels of sexual steroid hormones and behavioral studies to understand the factors related to the species´s reproductive cycle.

O réptil Kinosternon scorpioides é um quelônio de água doce popularmente conhecido como jurará, encontrado na Baixada Maranhense, Maranhão, Brasil. Diante da carência de informações científicas sobre a biologia reprodutiva desta espécie, objetivamos descrever a biometria testicular e corporal, assim como, e o índice gonadossomático (IGS), em espécimes adultos provenientes de habitat natural. Utilizamos 20 indivíduos machos adultos, coletados no período chuvoso (n = 10) e período seco (n = 10), dos quais extraímos informações da biometria corpórea e testicular, assim como o índice gonadossomático e testes de correlação entre estas medidas. Encontramos que a biometria corpórea de Kinosternon scorpioides de vida livre é semelhante ao encontrado em outros estudos com animais adultos criados em cativeiro. No entanto, o peso corpóreo foi maior em animais coletados no período chuvoso que o encontrado em animais coletados no período seco. A biometria testicular apresenta variações entre os animais de período chuvoso e seco, no entanto os índices gonadossomáticos não variaram entre os animais dos diferentes grupos, portanto sugerimos estudos relacionados a níveis de hormônios esteroides sexuais e estudos comportamentais para auxiliar na compreensão dos fatores relacionados ao ciclo reprodutivo da espécie.

Origem e distribuição do nervo retal caudal em equinos sem raça definida / Origin and distribution of the caudal rectal nerve in mixed breed horses

Objetivou-se estudar a origem e distribuição do nervo retal caudal em 30 fetos de equinos sem raça definida provenientes do Frigorífico Pomar, Araguari-MG. Para isso, injetou-se formaldeído a 10% por meio de canulação da aorta descendente torácica e, posteriormente, o material foi mantido submerso na referida solução, por um período mínimo de 48 horas antes do início da dissecação. Para observação da origem do nervo citado, foram realizadas: uma incisão longitudinal ao longo da linha mediana ventral, desde a cartilagem xifóide do processo xifóide do osso esterno, até a borda caudal da sínfise pélvica; e duas outras incisões verticais, uma em cada antímero, até alcançar a linha mediana dorsal. Dessa forma, desarticulou-se a sínfise pélvica até atingir a cavidade pélvica, da qual foram retirados todos os órgãos. Para análise da distribuição dos ramos musculares, realizou-se uma incisão na pele do terço médio da perna e outra vertical na pele da face medial da coxa, estendendo-a da raiz do membro pélvico até a primeira incisão. Em sequência foram contornados a raiz da cauda, o ânus e os órgãos genitais externos, rebatendo-se então a pele e as fáscias das regiões glútea, coxa e perna. Os dados obtidos foram analisados através do teste de Tukey (p<0,05). O nervo originou-se dos ramos ventrais dos nervos espinhais sacrais 3º (S3), 4º (S4) e 5º (S5); e distribuiu nos músculos: coccígeo, levantador do ânus, sacrocaudal medial ventral e esfíncter externo do ânus. Não houve diferença significativa entre a frequência dos ramos musculares e os antímeros, independente do número de ramos musculares (p=0,97).

The objective was to study the origin and distribution of the caudal rectal nerve in 30 fetuses of mixed breed horses from Frigorífico Pomar, Araguari/MG, Brazil. Formaldehyde at 10% were injected into the thoracic descending aorta and, subsequently, the material was kept immersed in this solution, for at least 48 hours before dissection. To find the origin of the mentioned nerve, we made: a longitudinal incision along the ventral midline, from xiphoid cartilage of the xiphoid process of the sternum bone to the caudal pelvic symphysis; and two vertical incisions, one at each antimere until reaching the dorsal midline. Therefore, we disarticulated the pelvic symphysis until the pelvic cavity, from which all organs were removed. To analyze the distribution of muscular branches, we made a incision in the skin of the middle leg and a vertical incision in skin of the medial thigh, extending it from the root of the pelvic limb to the first incision. In the following we circumvented the root of the tail, anus and genitalia, the hitting up the skin and fascia of the gluteal redion, thigh and leg. Data obtained were analyzed using the Tukey test (p<0.05). The nerve originated from the ventral branches 3rd, 4th and 5th sacral spinal nerves (S3, S4 and S5, respectively); and distributed into the coccygeus, levator ani, medial ventral sacrocaudal and external anal sphincter muscles. There wasn't no significant difference between the frequency of muscular branches and antimeres, independently of the number of muscular branches (p=0.97).

Seasonal morphological variation of the vas deferens of scorpion mud turtle (Kinosternon scorpioides) / Variação morfológica sazonal dos ductos deferentes de tartaruga jurará (Kinosternon scorpioides)

This study aimed to characterize the morphology of the vas deferens of Kinosteron scorpioides by macroscopic and microscopic analysis. Were used 20 adult male jurarás collected at regular intervals during the year and divided into four experimental groups in the rainy and dry seasons, being processed for light microscopy, scanning electron microscopy and transmission electron microscopy. Morphometry for tubular and luminal diameters and epithelial height were also performed. On rainy season, vas deferens presented pseudostratified epithelium with cylindrical cells, spermatozoids and milky fluid in the lumen, with cytoplasmic organelles and lipid vesicles. On dry season, epithelium was pseudostratified with cuboid cells, with cellular debris and no spermatozoids. There was significant variation (p<0,05) for morphometry of vas deferens, with lower values of tubular and luminal diameters on rainy season, and higher epithelial height on dry season.

Este estudo teve como objetivo caracterizar a morfologia dos ductos deferentes de Kinosteron scorpioides por meio de análise macroscópica e microscópica. Foram utilizados 20 machos adultos, coletados em intervalos regulares durante o ano, os quais foram divididos em quatro grupos experimentais nas estações chuvosa e seca. Os ductos deferentes foram processados para análise por microscopia de luz, microscopia eletrônica de varredura e microscopia eletrônica de transmissão. Morfometria para diâmetros tubular e luminal e altura epitelial também foram realizadas. Na época das chuvas, o ducto deferente apresentou epitélio pseudoestratificado com células cilíndricas, espermatozoides e líquido leitoso no lúmen, além de com organelas citoplasmáticas e vesículas lipídicas. Na estação seca, o epitélio do ducto deferente foi do tipo pseudoestratificado com células cuboides e debris celulares, sendo que nenhum espermatozoide foi encontrado nesta estação. Houve variação significativa (p <0,05) para a morfometria dos ductos deferentes, com menores valores de diâmetros tubular e luminal na estação chuvosa, e maior altura do epitélio na estação seca.

Origin and distribution of the ischiatic nerve in mixed-breed sheep / Origem e distribuição do nervo isquiático em ovinos sem raça definida

Current research studied, by dissection, the origin and distribution of the ischiatic nerve in 30 fetuses of mixed-breed male or female sheep (Ovis aries), obtained from abortions, stillborns and natural deaths of pregnant females on farms in the Triângulo Mineiro region, state of Minas Gerais, Brazil. Formaldehyde 10% was injected through the cannulation of descending thoracic aorta and the material was kept immersed in the solution for at least 48 hours before dissection. The ischiatic nerve originated from the ventral branch of the last lumbar spinal nerve, either from the sixth lumbar spinal nerve (L6) or from the seventh (L7), when present, and from the ventral branches of first and second sacral spinal nerves (S1 and S2, respectively), and possibly from the ventral branch of third sacral spinal nerve (S3). The ischiatic nerve provided branches to the superficial gluteal, middle gluteal, accessory gluteal, deep gluteal, gemelli, quadratus femoris, adductor, biceps femoris, semitendinosus and semimembranosus muscles. The tibial and common peroneal nerves were the terminal branches of the ischiatic nerve, originating distally towards the greater trochanter of the femur bone. Wilcoxon’s test (0.05) showed that statistically there were no significant differences between the frequencies of the muscular branches of the ischiatic nerve and the antimeres, regardless of the number of muscular branches.

O presente trabalho estudou, por meio de dissecações, a origem e distribuição do nervo isquiático em 30 fetos de ovinos (Ovis aries) sem raça definida, machos ou fêmeas, obtidos de abortos, natimortos e mortes naturais de fêmeas gestantes de núcleos criatórios na região do Triângulo Mineiro, estado de Minas Gerais, Brasil. Injetou-se formaldeído a 10% por meio de canulação da aorta descendente torácica e, posteriormente, o material foi mantido submerso na referida solução por um período mínimo de 48 horas antes do início das dissecações. O nervo isquiático originou-se do ramo ventral do último nervo espinhal lombar, ora do sexto nervo espinhal lombar (L6), ora do sétimo (L7), quando presente, e dos ramos ventrais dos primeiro e segundo nervos espinhais sacrais (S1 e S2, respectivamente), podendo apresentar a contribuição do ramo ventral do terceiro nervo espinhal sacral (S3). O nervo isquiático cedeu ramos aosmúsculos: glúteo superficial, glúteo médio, glúteo acessório, glúteo profundo, gêmeo, quadrado femoral, adutor, bíceps femoral, semitendinoso e semimembranoso. Os ramos terminais do nervo isquiático foram os nervos tibial e fibular comum, tendo suas origens distalmente ao trocânter maior do fêmur. Estatisticamente, através da aplicação do teste de Wilcoxon (0,05), não houve diferenças significativas entre as frequências dos ramos musculares do nervo isquiático e os antímeros, independentemente do número de ramos musculares.