Fruit dehiscence mechanism and release of dimorphic seeds with different germination properties in Commelina erecta.

Commelina erecta is a successful weed species. The aims of this study were to analyse the morpho-anatomy of the fruit and dimorphic seeds of the weed C. erecta, the dynamics and type of dormancy, and water entry. Flowers and fruits at different development stages were processed using standard anatomical techniques. Besides, experiments of imbibition, germinability and water entry were performed on both seed types. In the fruit of C. erecta, free and coated seeds are developed within dehiscent and indehiscent carpels, respectively. Dehiscent carpels open through a region of mechanical weakness in the dorsal vascular bundle. This region does not form in the indehiscent carpel. The main anatomical differences between the two seed types were observed in the testa and in the number of covering layers. Imbibition experiments showed that the covering of both seed types is water permeable, so these seeds lack physical dormancy and may exhibit physiological dormancy. Germinability experiments showed that the dormancy in free seeds is variable throughout the reproductive season, whereas, in coated seeds, it is high throughout the reproductive season. The embryotega is an area where the hardness of the seed coat is interrupted and facilitates water entry. Differences in the morpho-anatomy of carpels result in the formation of dimorphic seeds with different covering layers and different germination properties. These different properties allow some seeds germinate immediately after falling from the mother plant, and others to be incorporated into the seed bank. These results are useful for designing weed management strategies in agroecosystems.

Uterine Tube Resection by Vaginotomy as an Alternative to Ovariectomy in Mature Cattle.

The prevention of pregnancy is desirable for female cattle destined for sale in the northern Australian rangelands for both economic and welfare reasons. Controlled access to bulls is often not feasible, nor are any non-surgical methods currently available. Many females are therefore surgically spayed. This study describes a technique for uterine tube resection (UTR), which leaves the ovaries intact and is performed using a vaginal approach, and compares the outcomes from 70 Brahman cows subjected to the procedure with 60 heifers spayed using the dropped ovary technique. The animals were monitored for 10 days following the surgery. There were no mortalities, and two animals were treated for illnesses after the UTRs and recovered. The animals subjected to both surgical procedures showed signs of pelvic discomfort and mild inflammation during recovery. The cows gained an average of 9.3 kg (SD 14.5 kg) of weight over the 10 days of the study compared to the spayed heifers, which lost 3.5 kg (SD 13.3 kg), with 19 and 63% of the animals in each of the groups losing weight, respectively. Uterine tube resection can be considered as a viable alternative to surgical spaying.

Surgical Anatomy for Sterilization Procedures in Female Capybaras.

Capybaras are the largest rodents cohabiting with humans within urban and peri-urban green areas and are known by their prolificity. Surgical contraception has been recommended by official organizations as a way to control capybara populations in areas of zoonotic disease transmission, but little data are available concerning surgical anatomy. To obtain objective anatomical descriptions related to reproductive organs, eight female capybaras cadavers were dissected. The stratigraphy of the lateral (flank) and ventral, post-umbilical (on the linea alba) abdominal wall is described as well as the vascular anatomy of reproductive organs and their syntopy with the abdominal viscera. We commented on the access to the uterine tubes and uterine horns for each approach, and for better description of abdominal wall stratigraphy, abdominal ultrasonography was performed in one live female. All of the animals were provenient from "in situ" population management projects that were properly authorized. Similar abdominal wall stratigraphy was found in comparison to domestic mammals, with emphasis on a thick cutaneous muscle, a thin linea alba, and a large, loose cecum. The uterine tubes were easily accessed by bilateral laparotomy, allowing tubal removal/ligation procedures, while uterine horn exposure was more readily reached by a midline post umbilical celiotomy, favoring horn ligature and hysterotomy techniques. This study can help achieve more efficient contraceptive surgeries in capybaras, reducing the total surgical time and enhancing animal welfare.

Anatomic nomenclature and 3-dimensional regional model of the human ovary: call for a new paradigm.

The ovaries are the female gonads that are crucial for reproduction, steroid production, and overall health. Historically, the ovary was broadly divided into regions defined as the cortex, medulla, and hilum. This current nomenclature lacks specificity and fails to consider the significant anatomic variations in the ovary. Recent technological advances in imaging modalities and high-resolution omic analyses have brought about the need for revision of the existing definitions, which will facilitate the integration of generated data and enable the characterization of organ subanatomy and function at the cellular level. The creation of these high-resolution multimodal maps of the ovary will enhance collaboration and communication among disciplines and between clinicians and researchers. Beginning in March 2021, the Pediatric and Adolescent Gynecology Program of the Eunice Kennedy Shriver National Institute of Child Health and Human Development invited subject-matter experts to participate in a series of workshops and meetings to standardize ovarian nomenclature and define the organ's features. The goal was to develop a spatially defined and semantically consistent terminology of the ovary to support collaborative, team science-based endeavors aimed at generating reference atlases of the human ovary. The group recommended a standardized, 3-dimensional description of the ovary and an ontological approach to the subanatomy of the ovary and definition of follicles. This new greater precision in nomenclature and mapping will better reflect the ovary's heterogeneous composition and function, support the standardization of tissue collection, facilitate functional analyses, and enable clinical and research collaborations. The conceptualization process and outcomes of the effort, which spanned the better part of 2021 and early 2022, are introduced in this article. The institute and the workshop participants encourage researchers and clinicians to adopt the new systems in their everyday work to advance the overarching goal of improving human reproductive health.

Morphological and structural differences between the hemipenes and hemiclitores of golden lancehead snakes, Bothrops insularis (Amaral, 1922), revealed by radiography.

The golden lancehead (Bothrops insularis) is a critically endangered and island endemic snake. A remarkable characteristic of golden lanceheads is the high frequency of females showing hemiclitores. Here, we use radiography to identify morphological and structural differences between the hemipenes and hemiclitores in captive individuals. Sex was identified using the probing method and confirmed by visualizing the gonads by ultrasound. Hemipenes appeared as herringbone-shaped structures with bone radiopacity and hemiclitores as triangular structures with soft tissue radiopacity. These differences suggest that hemiclitores spines fail to develop the level of ossification observed in hemipenis spines.

Morphological and structural differences between the hemipenes and hemiclitores of golden lancehead snakes, Bothrops insularis (Amaral, 1922), revealed by radiography

The golden lancehead (Bothrops insularis) is a critically endangered and island endemic snake. A remarkable characteristic of golden lanceheads is the high frequency of females showing hemiclitores. Here, we use radiography to identify morphological and structural differences between the hemipenes and hemiclitores in captive individuals. Sex was identified using the probing method and confirmed by visualizing the gonads by ultrasound. Hemipenes appeared as herringbone-shaped structures with bone radiopacity and hemiclitores as triangular structures with soft tissue radiopacity. These differences suggest that hemiclitores spines fail to develop the level of ossification observed in hemipenis spines.

New findings on the functional morphology of the male genitalia of the blood-feeding bug Rhodnius prolixus in the light of a different observation on living tissue.

Among insect species, the male genitalia evolved many different anatomical features to ensure reproductive success. Males of primitive insects do not copulate but transfer sperm packaged in a spermatophore to the female, whereas males of the most advanced insects copulate and deliver free sperm to the storage organ, the spermatheca, in the female reproductive tract. Based on previous studies on several species of triatomine bugs (Rhodnius prolixus included), Triatominae are thought to use an intermediate form of sperm transfer in which the male genitalia have evolved to carry out both copulation and spermatophore formation. Previous observations on chemically fixed tissue of R. prolixus appear to show that the penis, the aedeagus, contains a much-folded internal cuticle which is a collapsed sac that everts from the aedeagus during copulation for the formation and delivery of the spermatophore directly to the female genital chamber. However, observations on living tissue of these structures in R. prolixus show that this internal cuticle functions as a tube through which male secretions pass through the aedeagus to the vagina. The organization of this cuticle in the context of the various anatomical structures of the aedeagus, its different morpho-functional meaning during sperm transfer in R. prolixus, the use of living versus chemically fixed tissue and a new understanding of previous observations are discussed.

Venereal Transmission of Vesicular Stomatitis Virus by Culicoides sonorensis Midges.

Culicoides sonorensis biting midges are well-known agricultural pests and transmission vectors of arboviruses such as vesicular stomatitis virus (VSV). The epidemiology of VSV is complex and encompasses a broad range of vertebrate hosts, multiple routes of transmission, and diverse vector species. In temperate regions, viruses can overwinter in the absence of infected animals through unknown mechanisms, to reoccur the next year. Non-conventional routes for VSV vector transmission may help explain viral maintenance in midge populations during inter-epidemic periods and times of adverse conditions for bite transmission. In this study, we examined whether VSV could be transmitted venereally between male and female midges. Our results showed that VSV-infected females could venereally transmit virus to uninfected naïve males at a rate as high as 76.3% (RT-qPCR), 31.6% (virus isolation) during the third gonotrophic cycle. Additionally, VSV-infected males could venereally transmit virus to uninfected naïve females at a rate as high as 76.6% (RT-qPCR), 49.2% (virus isolation). Immunofluorescent staining of micro-dissected reproductive organs, immunochemical staining of midge histological sections, examination of internal reproductive organ morphology, and observations of mating behaviors were used to determine relevant anatomical sites for virus location and to hypothesize the potential mechanism for VSV transmission in C. sonorensis midges through copulation.

Genital morphology and the mechanics of copulation in the millipede genus Pseudopolydesmus (Diplopoda: Polydesmida: Polydesmidae).

Mate choice, copulation, genital morphology, and sperm storage are not very well understood in millipedes. The use of three-dimensional x-ray computed tomography (µCT) provides new morphological data regarding millipede reproductive systems in both the female and male, including chitinous sclerites and membranes, muscles, glands, oviducts, and sperm conduits. Here we present a complete integrated account of the morphology and function of the female genital organs in the family Polydesmidae (Diplopoda: Polydesmida) using µCT, UV fluorescence imaging, and scanning electron microscopy. These data allow us to consider competing hypotheses regarding millipede vulva formation. We additionally present the morphology of copulatory interface in Pseudopolydesmus Attems, 1898 using images of a mating pair in copula and by simulating the interface of the organs using 3D models from µCT, allowing us to tentatively identify a lock-and-key-like mechanism. Finally, we use µCT to reveal the topology of the seminal canal in the gonopod of male Pseudopolydesmus, a topic that has remained unresolved for nearly 80 years.

Intertidal Euryleptid polyclads and description of a new Stylostomum Lang, 1884 from Maharashtra, India.

The family Euryleptidae, consisting of 19 genera, is as colourful and distinct as the family Pseudocerotidae. Five species of Euryleptidae encountered during surveys in the intertidal rocky shores of Ratnagiri, Maharashtra are presented in the current study. Cycloporus variegatus is new records to India. Cycloporus australis and C. reticulatus are new records to India and reported for the second time after their first formal descriptions in 1982 and 2002 respectively. Eurylepta aurantiaca is a new record to the Indian ocean. The study also describes the new species Stylostomum mixtomaculatum sp. nov. and it is the first report of the genus Stylostomum from the tropical realms. Since Stylostomum and Acerotisa are known to be closely allied genera, efforts have been made to review their species assemblages and throw light on the existing ambiguities within the available information. With this report, the number of euryleptid species from Indian waters increases to eight.

The ontogeny of the female reproductive system in the parasitic castrator pea crab Calyptraeotheres garthi: Implications for its mating system.

The knowledge of the mating system of pea crabs is still fragmentary as it remains dubious whether females copulate in the juvenile and free-living 'hard' or in the obligatory symbiotic stages (adult stage 'V' or intermediate stages II to IV). To discriminate between these two possibilities, we analysed the female seminal receptacles, vagina and opercula, and the sperm content in different stages of the pea crab Calyptraeotheres garthi. Our histology and scanning electron microscopy results revealed that in the hard stage the seminal receptacle is simple without secretory epithelia, and vagina and opercula are not controlled by musculature. In stages II to IV, the seminal receptacles, vagina, and opercula are under development and these structures reach maturity in stage V. These results suggest that females become receptive in stage V and not during predating stages. We found no spermatozoa in SR of 'hard' and stage II to IV females while these structures were loaded of sperm in most stage V, indicating that females start to mate in stage V. Our results support the notion that males of C. garthi roam among hosts in search for sedentary stage V females, as predicted by Baeza and Thiel's () model of mating systems for symbiotic crustaceans. Nevertheless, we failed to reveal whether females mate repeatedly: the accumulation of sperm in larger females might indicate occurrence of multiple copula or a high variability in male sperm transfer.

"When You're a Baby You Don't Have Puberty": Understanding of Puberty and Human Reproduction in Late Childhood and Early Adolescence.

Basic knowledge of human reproduction can help youth prepare for puberty and make later classes focused on advanced reproductive health topics manageable. With the intention of potentially informing the creation of learning materials, we conducted a needs assessment among children ages 7 to 12 in our suburban Chicago community to ascertain their current understanding of, and beliefs and misconceptions about, human reproduction, and to determine their needs for additional reproductive health education. We held qualitative focus group interviews with local children. Participants primarily reported learning about these topics from their parents prior to receiving school-based education in fifth grade. Their level of understanding was relatively low. They had little knowledge of internal sexual organs, expressed a range of beliefs about conception ranging from inaccurate to accurate but incomplete, and voiced concerns about transitioning into adolescence. This suggests a need for additional resources that provide comprehensible descriptions of reproductive health processes and mitigate puberty-related concerns.

Gonadal development of Peprilus medius (Peters, 1869) (Perciformes: Stromateidae) from Southeast of the Gulf of California, Mexico / Desarrollo gonádico de Peprilus medius (Peters, 1869) (Perciformes: Stromateidae) del Sureste del Golfo de California, México

The gonadal development assessment is a fundamental work in researching the reproduction of Peprilus medius, on the way to understand its population dynamics and to achieve a sustainable management of its fisheries. The diagnosis based on morphochromatic features is the quicker, more practical and cheaper method, and properly validated, it may be an accurate procedure. This is particularly useful in researches when it is required to provide prompt and accurate information to support decision-making for fisheries management, and during long-term fisheries monitoring to detect changes in reproductive patterns due to environmental anomalies. These are issues of concern in P. medius and other fishery resources. In this context, a scale that describes the gonadal development through morphochromatic and histological features is presented, and plus anatomical observations of the reproductive organs. Ovarian development was characterized through six phases: immature, development (sub-phases: early and late), mature, spawning (sub-phases: partial and partial post-spawning), post-spawning and resting. Testicular development was described through five phases: immature, development, ejaculation, ejaculated and resting. The position and shape of the reproductive organs are apparently defined by the shape of the fish and the visceral cavity. P. medius's gonads show a gonadal lobe at lower position and an upper lobe in the visceral cavity, and both lobes presented a horizontal placement from gonopore toward the back of the fish. In addition, gonadal deformities occurrence due to deformities in the visceral cavity was evidenced. We recommend to use presented descriptions as a guide in gonadal assessment.

La evaluación del desarrollo gonádico es una labor fundamental para investigar la reproducción de Peprilus medius, en vías a comprender la dinámica de sus poblaciones y lograr un manejo sustentable de sus pesquerías. El diagnóstico a partir de características morfocromáticas es el método más rápido, práctico y barato, y adecuadamente validado puede ser un procedimiento preciso. Este es particularmente útil en investigaciones cuando se requiere aportar información rápida y precisa que apoye la toma de decisiones de manejo pesquero, y durante los monitoreos pesqueros de largo plazo, que permiten detectar cambios en los patrones reproductivos debido a anomalías ambientales. Estos son temas preocupantes en P. medius y otros recursos pesqueros. En ese contexto se presenta una escala que describe el desarrollo gonádico a través de características morfocromáticas e histológicas, y además se presentan observaciones anatómicas de los órganos reproductores. El desarrollo ovárico fue caracterizado a través de seis fases: inmadura, desarrollo (subfases: inicial y avanzado), maduro, desove (subfases: parcial y postdesove parcial), postdesove y reposo. El desarrollo testicular fue descrito a través de cinco fases: inmadura, desarrollo, eyaculación y reposo. La posición y forma de los órganos reproductores están aparentemente definidos por la forma del pez y su cavidad visceral. Las gónadas de P. medius muestran un lóbulo gonádico en posición inferior y uno superior en la cavidad visceral, y ambos lóbulos presentan una colocación horizontal desde el gonoporo hacia la parte posterior del pez. Además se evidencia la ocurrencia de deformidades en las gónadas debido a deformidades en la cavidad visceral. Recomendamos utilizar las descripciones presentadas como una guía en la evaluación de las gónadas.

Reproductive system, mating behavior and basic ecology of an extremely rare tropical snail: Drymaeus tripictus (Stylommatophora: Bulimulidae) / Sistema reproductivo, comportamiento de apareamiento y ecología básica de un caracol tropical extremadamente raro: Drymaeus tripictus (Stylommatophora: Bulimulidae)

Abstract Very little is known about the ecology and biology of Drymaeus tripictus, an extremely rare and endemic land snail species from Costa Rican highlands. I studied the ecology and reproductive biology of D. tripictus from April 2009 through June 2010 in an old forest, a young forest and a Cupressuslusitanica plantation in central Costa Rica. Every three months I visited each habitat and collected specimens in 20 random sampling plots (3x3 m2 each). I observed the snail's activity and microhabitat preference in the field, and in the laboratory I recorded high definition videos of its mating behavior and analyzed reproductive morphology with light microscopy. The snail is more abundant in the old forest (0.017 ind./m2) and prefers leaves with little epiphyllous cover (0-25 % cover, chi-square test, p <0.0001). During the dry season the snails become active between 20:00 pm and 8:00 am (chi-square = 22.65, df=3, p < 0.0001); they are inactive mainly during the afternoon (11:00 am to 16:59 pm). I found active individuals mostly on the upper side of leaves, where they feed (Chi-square =6.76, df=1, p = 0.0093). Mating is unilateral, by shell mounting, with cryptic phallus intromission and without role switching or multiple mating. Its reproductive system is morphologically similar to that of Drymaeus costaricensis. Mating behavior is as expected for snails with high-spired shells, except for the lack of role switching. The density of D. tripictus is low even when compared with other endangered bulimulids. Rev. Biol. Trop. 64 (1): 55-68. Epub 2016 March 01.

ResumenSe conoce muy poco sobre la ecología y biología del caracol terrestre Drymaeus tripictus. Se trata de una especie extremadamente escasa y endémica de las zonas altas de Costa Rica. Estudié la ecología y biología reproductiva de D. tripictus de abril 2009 a junio 2010 en un bosque maduro, un bosque jóven y una plantación de Cupressus lusitanica en Costa Rica. Cada tres meses visité esos hábitats y recolecté especímenes en 20 puntos de muestreo (cada uno de 3x3 m2). Estudié actividad y preferencias de hábitat en la naturaleza. En el laboratorio grabé en alta definición el comportamiento de apareamiento y analicé la morfología reproductiva con un microscopio estereoscópico de luz. El caracol es mas abundante en el bosque maduro (0.017 ind/m2) y prefiere hojas con poca cobertura de epífilos (25% o menos de cobertura, chicuadrado, p < 0.0001). En la época seca, se activan entre las 8:00 pm y las 8:00 am principalmente (chi-cuadrado = 22.65, p <0.0001). En la tarde se inactivan (11:00 am to 16:59 pm). Los individuos activos se encuentran principalmente en el haz de las hojas (Chi-square =6.76, df =1, p = 0.0093), que es donde se alimentan. El apareamiento es unilateral por "montaje de concha", no hacen cambio de roles sexuales y la intromisión fálica es críptica. Su sistema reproductivo es morfológicamente similar al de Drymaeus costarricensis. El comportamiento de apareamiento es como se espera de un caracol de concha con espira alta, excepto por la ausencia de cambio de roles. La densidad de D. tripictus es mas baja que la de otros bulimulidos considerados en peligro.

Conhecimento de adolescentes grávidas sobre anatomia e fisiologia da reprodução / Knowledge of pregnant adolescents about reproductive anatomy and physiology in a municipality of Southern Brazil

OBJETIVOS: Verificar o conhecimento sobre alguns aspectos do aparelho genital feminino, da fisiologia da reprodução e sua associação com características sociodemográficas e "escolhas" reprodutivas em adolescentes gestantes. MÉTODOS: Realizou-se um estudo de corte transversal com 200 adolescentes primigestas, durante a primeira consulta de pré-natal no Ambulatório da Mulher de Indaiatuba, São Paulo. Foram feitas entrevistas face a face, com questionário estruturado e um modelo feminino tridimensional confeccionado artesanalmente para coleta dos dados. Os dados foram analisados utilizando-se os testes Qui-quadrado de Pearson, ou Exato de Fisher, e por regressões logísticas múltiplas, para verificar associações entre indicadores do conhecimento sobre anatomia dos órgãos genitais femininos, fisiologia dos órgãos e da reprodução com características sociodemográficas e "escolhas" reprodutivas. RESULTADOS: A maioria tinha conhecimento insatisfatório sobre anatomia (55,5 por cento), com os órgãos externos sendo identificados com maior facilidade e melhor localizados do que os internos; fisiologia dos órgãos (61 por cento); e aspectos fisiológicos da reprodução (76,5 por cento). Algumas associações significativas foram estabelecidas entre o conhecimento e a idade dos parceiros, diferença de idade do casal, manutenção do vinculo após ocorrência da gravidez, filiação religiosa e escolaridade da adolescente. Não houve associação entre os indicadores de conhecimento estudados com a utilização de método anticoncepcional na primeira relação sexual e a intenção de ter um filho naquele momento. CONCLUSÃO: Este estudo faz emergir a complexidade da relação entre o conhecimento sobre anatomia e fisiologia reprodutivas e a temática da gravidez na adolescência, evidenciando a necessidade de abordagens mais contextualizadas dos conteúdos de programas de educação sexual, quando seu foco for a redução da gravidez precoce.

OBJECTIVES: To study knowledge of some aspects of the female reproductive anatomy and physiology and their association with socio-demographic and reproductive "choices" of pregnant adolescents. METHODS: A cross-sectional study was performed with 200 first time pregnant adolescents who attended a public women's health clinic in the municipality of Indaiatuba, Sao Paulo, Brazil. During their first prenatal care visit, face-to-face interviews were conducted using a structured questionnaire and a three-dimensional handmade female model. Bivariate data analyses were performed using Person's Chi-square or Fisher Exact test. Data were also analyzed using multivariate logistic regression models to test for associations of indicators of knowledge of female reproductive anatomy, physiology of female reproductive organs and physiology of reproduction with socio-demographic characteristics and reproductive "choices". RESULTS: The majority had little knowledge of anatomy (55.5 percent), with external organs more easily identified and placed than the internal; of physiology of reproductive organs (61.0 percent), and of physiology of reproduction (76.5 percent). Associations were found between knowledge and age of partner, couple difference of age, maintenance of the relationship with partner after pregnancy, religious affiliation, and level of education. No association was found between indicators of knowledge with use of contraceptives at first intercourse and with intention of having the baby at that time. CONCLUSION: This study addressed the complexity of the relationship between knowledge of reproductive anatomy and physiology and the theme of adolescent pregnancy, and emphasized the need for more contextualized approaches of programmatic contents on sexual education, in view of the intention to reduce early pregnancy.

Características seminais, corpóreas e anatômicas do aparelho reprodutor de reprodutores da raça canchim aos 14 e 48 meses de idade. / Anatomical, corporal and seminal characteristics of the reproductive system of canchim breed reproductors at ages from 14 to 48 months / Características seminales, corpóreas y anatómicas del aparato reproductor de reproductores de la raza canchim a los 14 y 48 meses de edad

Foram utilizados 20 touros da raça Canchim em inatividade sexual, divididos em grupo 1 (G1), constituído de 10 animais com 14 meses de idade e grupo 2 (G2), com 10 animais de 48 meses de idade. A proposta desse estudo foi investigar as características dos ejaculados e das mensurações anatômicas do trato reprodutivo da raça Canchim. Os parâmetros obtidos foram: peso médio de 445,5 e 706,02 kg; circunferência escrotal de 31,80 e 36,25 cm e índice de massa corpórea de 270,33 e 346,73 kg/m2 para o G1 e G2, respectivamente, com diferenças significativas (p < 0,05) entre eles. Realizaram-se quatro colheitas de sêmen por touro por meio de eletroejaculação, com intervalos de 14 dias, verificando-se diferença significativa (p < 0,05) para os defeitos espermáticos totais, entre a primeira (5,48) e a terceira colheitas (1,08), no G2. Os resultados sugerem que o desenvolvimento do aparelho reprodutivo e a espermatogênese estão presentes aos 14 meses de idade.

Twenty bulls of the Canchin breed in sexual inactivity were divided in group 1(G1) with ten animals at the age of 14 months old and group 2 (G2) with ten animals at the age of 48 months old. The purpose of this study was to investigate the characteristics of the ejaculators and anatomic measurements of reproductive tract in Canchim breed. The parameters obtained were the average weight from 445.5 to 706.02 kg, scrotal circumference from 31.8 to 36.25 cm and Corporal Mass Index from 270.33 to 346.73 kg/m² for G1 and G2 respectively with a significant difference (p<0.05). Four semen collections per bull were made with electro ejaculation with intervals of 14 days, and it showed significant difference (p<0.05) for the total spermatic flaws, between the first (5.48) and the third collect (1.08) in G2. These results suggest that the development of the reproductive tract and the spermatogenesis are present at the age of 14 months old.

Fueron utilizados 20 toros de la raza Canchim en inactividad sexual, divididos en grupos:Grupo 1 (G1) con 10 animales, con edades de 14 meses y el grupo 2 (G2) con 10 animales, con edades de 48 meses, teniendo como objetivo verificar la adaptación al clima tropical, por medio de las características de los eyaculados y medidas anatómicas del aparato reproductivo. Los parámetros obtenidos fueron peso medio de 445,5 y 706,02 kg; circunferencia escrotal de 31,80 y 36,25 cm e índice de masa corpórea de 270,33 y 346,73 kg/m² para el G1 y G2, respectivamente, con diferencias significativas (p<0,05). Fueron realizadas cuatro colectas de semen por toro, con intervalo de 14 días, por medio de electroeyaculación verificando diferencias significativas (p<0,05) para los defectos espermáticos totales entre la primera (5,48) y la tercera colecta (1,08) en el G2. Los resultados sugieren que el desarrollo del aparato reproductor y la espermatogénesis están presentes a los 14 meses de edad.

The stumptail macaques of China.

The stumptail macaque species Macaca thibetana and Macaca arctoides replace one another from north to south in subtropical and tropical China. These species differ in external and cranial characters. Neonatal pelage color is pale grayish-brown in M. thibetana and whitish in M. arctoides. In adults, ventral pelage is whitish in M. thibetana and brown in M. arctoides. The forehead and cheeks are thickly furred in adult M. thibetana and bald in M. arctoides. Facial skin color typically is sexually dimorphic in M. thibetana-buffy in males and reddish in females-and monomorphic in M. arctoides-reddish in both sexes. Head and body length, weight, relative tail length, and relative ear length all tend to average greater in M. thibetana than in M. arctoides. Skull length, rostral-postrostral ratio, and relative canine length in males average greater in M. thibetana. than in M. arctoides; relative zygomatic breadth and relative bimalar breadth average greater in M. arctoides than in M. thibetana. Reproductive anatomy in both sexes is strikingly divergent in these two species. Although these species are adapted to different climatic zones, many aspects of their natural history are generally similar, as far as is now known. One apparent behavioral difference is that M. thibetana usually sleeps in caves or rocky crevices, while M. arctoides usually sleeps in trees.