Morphological aspects of the ovaries of turtle Kinosternon scorpioides raised in captivity (original) (raw)
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In this study we review the macro and microscopic description of the reproductive system of male and female Podocnemis lewyana neonates of 3.5 months of age. We found macroscopic differences in the morphology of the gonads, with ovaries being twice longer that testes, and testes being twice wider than ovaries. Microscopically we identified several immature elements, such as the lack of muscle layer in the oviduct of reptile females, and simple epithelia instead of pseudostratified epithelia in the oviduct and epididymis described in adults. We also describe a black pigment observed macroscopically in the mesovarium and macroscopically and histologically in the epididymis. This pigment is compatible with the center of melano-macrophages described in other vertebrates. Finally we described a supporting mesenchymal structure, the appendage of the oviduct, with was much longer than what has been described in other Podocnemis species.
Arquivo Brasileiro de Medicina Veterinária e Zootecnia, 2018
Studies on reproduction in sea turtles are important due to its life cycle, migratory patterns, high juvenile mortality and environmental impacts. This study aimed to analyse histomorphometrically gonads of C. mydas from the coastline of the Espírito Santo State, Brazil. Ovaries and testicles were collected between 2014 and 2015 from stranded animals. The material was fixed in formalin 10%, assessed macroscopically and processed for histomorphometrical evaluation. Gonads from 34 individuals were evaluated, twenty-four females and ten males. Macroscopic sexual identification presented 100% accuracy confirmed by histology. Sexual dimorphism was observed in one individual, which was considered as adult (CCL=1.023 m). Microscopy of female gonads revealed predominant previtellogenic follicles; oocyte diameter ranged between 161µm and 750µm and a positive correlation between ovarian length, largest oocyte and CCL was found. In males, autolysis was verified in five individuals. Viable test...
En este estudio se realizó una descripción macro y microscópica del sistema reproductivo de tortugas de Podocnemis lewyana de 3,5 meses de edad. Se hallaron diferencias macroscópicas en las gónadas, microscópicamente se identificaron varios elementos inmaduros. También se describe un pigmento negro observado macroscópicamente en el mesoovario de las hembras, y macroscópica e histológicamente en el epidídimo de los machos, y una estructura mesenquimatosa de soporte que identificamos como el apéndice del oviducto, la cual fue mucho más larga que las descritas en otras especies de Podocnemis.
Veterinary Medicine and Science, 2020
The Kinosternon scorpioides (scorpion mud turtle), popularly known as jurará in Maranhão state, Brazil, is in danger of extinction. It is a small freshwater turtle species belonging to the family Kinosternidae, whose average adult carapace length is 11.5-15.60 cm (Berry& Iverson, 2001; Ernest& Barbour, 1989). Research on the reproductive aspects of the scorpion mud turtle (K. scorpioides) has been carried out at the Center for Wild Animal Studies and Preservation (NEPAS) of the veterinary medicinecourse at Maranhão State University (UEMA), Brazil, holder of a breeding license (number 1899339/2008) issued by the Brazilian Institute of the Environment and Renewable Natural Resources (IBAMA/MA). Maranhão has a rainy and dry season: there are extensive wetlands and marshes from January to June, when fishing is the main subsistence activity and between July and December, these areas become dry and subsistence crops are grown. Although turtles are an important source of protein and economically valuable to the local populations of the state, little is known about their reproduction in nature (Viana et al., 2013). Turtles start their lives in eggs buried in the sand during the dry season. This behaviour reduces their basal metabolic rate when the environment is not amenable to activity. It has been reported that the reproductive
Oviductal morphology in relation to hormonal levels in the snapping turtle, Chelydra serpentina
Tissue and Cell, 2006
Microscopic and in situ visual observations were used to relate circulating hormone levels to morphological changes in the oviduct of the snapping turtle Chelydra serpentina throughout the ovarian cycle. Increase in levels of progesterone (P), estradiol (E2) and testosterone (T) levels coincide with an increase in number and growth of endometrial glands, luminal epithelial cells and secretory droplets throughout the oviduct. Testosterone and estradiol levels rose significantly (P < 0.05) after the May-June period and remained high throughout the rest of the summer. Progesterone levels remained stable throughout the summer, with a brief decline in July due to luteolysis. Hormonal values declined significantly (P < 0.001) at the end of the ovarian cycle in the fall. In situ visual observation of fresh oviducts at different stages of gravidity in recently ovulated turtles revealed that proteinaceous like components from the endometrial glands were released into the lumen to form fibers. The morphological features of the oviduct remained active throughout the summer months even though the snapping turtle is a monoclutch species which deposits all the eggs in late-May to mid-June. The high steroid levels correlate with and may be responsible for the secretory activity present throughout the summer and their decline correlates with change to low secretory activity in the fall. Calcium deposition accompanied by morphological changes in luminal cells are suggestive of secretory activity. In the egg-bearing turtles, uterine Ca2+ concentrations measured by flame atomic absorption spectrophotometry revealed significantly higher Ca2+ concentrations (P < 0.001) in eggs with soft shell than eggs without shell. There was a significant increase in calcium granules and proteinaceous fibers in luminal surface of the uterus during the period of eggshelling. This supports the fact that in the snapping turtle like in other reptiles, eggshelling process occurs in the uterus.
Ovarian follicular development in the hawksbill turtle (Cheloniidae: Eretmochelys imbricata L.)
Journal of morphology, 2012
Ovarian follicular development is an essential process in the determination of maturation stages associated with size. This association acquires importance when managing populations of threatened species. We histologically processed 11 prepubescent ovaries, four pubescent ovaries, and one breeding adult ovary with vitellogenic follicles using specific staining techniques to identify the follicular stages of Eretmochelys imbricata. Follicular stages were compared with maturation stages [including straight carapace length (SCL)]. The ovary presented several germinal beds and a lacunar system less histochemically and morphologically heterogeneous than that of crocodiles. During previtellogenesis (four stages), the oocyte grows rapidly due to the strong transcriptional activity of lampbrush chromosomes and numerous nucleoli, and the strong metabolism associated with lipid synthesis. The Stage III ooplasm showed a Sudan positive band. This stage was the most frequent in all ovarian secti...
Zoology, 2008
Sex identification in young sea turtles is challenging. Sea turtle neonates lack external dimorphic characteristics and heteromorphic sex chromosomes. We compared the morphology of the gonads and reproductive ducts of dead formalin-preserved hatchling and post-hatchling Caretta caretta, Dermochelys coriacea, and Chelonia mydas and identified sex-specific differences in these structures that are useful in assigning sex. We tested 11 gross gonadal and reproductive duct characteristics in 57 neonate sea turtles and verified the sex by histological examination. A suite of four characters was found to reliably indicate sex in the three species considered: paramesonephric duct size, mobility of the duct, presence of a complete lumen and gonad mobility. Additionally, gonad shape and edge form were dependable sex-specific characters in cheloniids but not in D. coriacea. Together, these morphological characteristics provide new and reliable methods to quickly distinguish sex in preserved neonate sea turtles without using more extensive histological methods. (J. Wyneken).
Journal of Morphology, 1995
Scanning electron and light microscopic studies reveal significant changes in the endometrial histophysiology of the soft-shelled turtle Lissemys punctata punctata during its seasonal reproductive cycle. Scanning electron microscopy shows the entire oviductal mucosa to be only slightly folded throughout the non-breeding period (regressive, quiescent, preparatory and recrudescent phases). With the onset of the breeding phase, the mucosa shows extensive foldings and convolutions. The adluminal mucosal lining of the non-breeding oviduct is covered by a tall, dense ciliary bed, interrupted by a few fissures and pits. Microvilli-bordered secretory cells only appear amongst the ciliated cells during the breeding phase. Light microscopic study reveals the mucosal epithelium to be low pseudostratified columnar throughout the non-breeding period. The breeding epithelium, on the other hand, is tall columnar and does contain clearly distinguishable ciliated and secretory cell types. Submucosal glands only appear for a short period (ovulation to oviposition) in the infundibulum and isthmus regions of the oviduct, but these glands are observed throughout the reproductive cycle in the tube and uterus. The secretory activity of the submucosal glands, which occur only during the peak breeding stages, involves release of vesicular secretory materials through the gland openings. The stimulated endometrial histology and activity during the breeding phase coincide with increased levels of serum estrogen and progesterone, whereas the regressed and inactive state of the endometrium is paralleled by decreased levels of these ovarian steroids. o 1995 Wiley-Liss, Inc. The general anatomy of the oviducts in reptilians has long been known (Fox, '77). Recent workers have studied various aspects of oviductal histophysiology including the influence of sex steroids on oviductal growth and function in tuatara, lizards, snakes, and crocodilians, viz., Sphenodon punctatus (Packard et al., '881, Sceloporus aeneus (Guillette and Jones, '851, Ctenosaura pectinata (Uribe et al., ,881, Crotaphytus collaris and Eumeces obsoletus (Guillette et al., '89), Sce-Eoporus woodi (Palmer, 'go), Thamnophis elegans (Mead et al., '81), Nerodia sp. (Kleis-San Francisco and Callard, '86), and Alligator mississippiensis (Palmer and Guillette, '92). However, studies on chelonian oviducts are relatively few. Along the length of the oviduct of the marine turtle Chelonia mydas, five regions have been distinguished, namely, infundibulum, magnum, aglandular segment, shell forming segment, and vagina (Aitken and Solomon, '76; Solomon and Baired, '77, '79; Owens, '80). The oviduct of other testudines has been divided into different regions such as infundibulum, tube (tuba, uterine, or glandular segment), isthmus (intermediate segment), uterus and vagina (cervical segment) (Parker, '31; Hansen and Riley, '41; Nicholson and Risley, '41; Salih, '65; Hattan and Gist, '75; Palmer and Guillette, '88, '90; Abrams-Motz and Callard, '91). Histologically, the oviductal wall in all reptiles comprises three layers, viz., 1) an inner mucosa/endometrium that includes an epithelium and a lamina propria consisting of connective tissue, glands, and blood vessels, 2) a middle smooth muscle layer/myometrium, composed of inner circular and outer o 1995 WILEY-LISS, INC.
Reproductive aspects of brazilian side-necked-turtles (Chelidae)
Boletín de La …, 2006
Resumen: El conocimiento de los parametros reproductores resulta fundamental a la hora de llevar a cabo actividades de gestión y conservación de especies. A partir de una revisión biblográfica se ha constatado que existe un amplio desconocimiento sobre los aspectos ...