Sexagem cirúrgica em aves silvestres

Relata-se a utilização da laparoscopia na sexagem de 349 aves silvestres nacionais e exóticas, pertencentes a 61 espécies, de 11 famílias e seis ordens. Foram sexadas aves com idades entre quatro meses e 42 anos e peso corpóreo entre 55g e 3,4kg. Com essa técnica foi possível visualizar as gônadas, avaliar seu estágio de desenvolvimento e observar os órgãos adjacentes. A técnica cirúrgica utilizando endoscópio rígido para sexagem de aves silvestres foi considerada rápida e segura. Nenhum óbito foi verificado durante ou em conseqüência do procedimento cirúrgico.

ULTRASTRUCTURE OF THE HINNY (EQUUS-ASINUS X EQUUS-CABALLUS) SEMINIFEROUS EPITHELIUM

The gonads and the germinative cells of 3 male hinnies were studied with light and transmission electron microscopy with the aim to observe the development of germ cells and verify the morphological modifications due to the hybridization. The hinny seminiferous epithelium presented Sertoli cells and spermatogonia with normal features and anomalous spermatocytes I. The other cells from the spermatogenic sequence were not seen. Most of the alterations began to occur in the cytes I, which presented nuclear vacuolization and deposits of amorphous material between the carioteca and the nuclear lamina, forming vesicles, or exaggerated chromatin condensation, resulting in pyknosis. In the cytoplasm vacuolization was also observed, besides organelle destruction.The arrest of meiosis due to lock of chromosome homologies leads to germinative cell degeneration and, therefore, the spermatogenesis arrest. This fact causes a profound alteration in the seminiferous epithelium morphology in comparison with the parental species.

PARTICIPATION OF OPIOID RECEPTORS IN THE MODULATION OF THE ANALGESIC RESPONSE BY ADRENAL AND GONADAL GLANDS

The involvement of opioid receptors in the analgesic response was evaluated by the tail-immersion test in simultaneously adrenalectomized and ovariectomized female Wistar rats (210-250 g). The reaction time (mean +/- SEM) for tail withdrawal from hot water decreased significantly 2 weeks after surgery (3.52 +/- 0.20 s) when compared to intact animals (6.09 +/- 0.23 s). Hormonal replacement with dexamethasone (50-mu-g/day) did not affect reaction time (3.38 +/- 0.19 s). However, this response was restored by combined adrenal and gonadal steroid substitution (estradiol 5-mu-g/day and progesterone 1.5-mu-g 6 h before the tests) therapy (5.11 +/- 0.45 s in animals treated with dexamethasone plus estradiol and 5.04 +/- 0.43 s in animals treated with dexamethasone plus estradiol plus progesterone). Naloxone (2 mg/kg) decreased the reaction time of animals treated with adrenal and gonadal steroids (5.11 +/- 0.45 vs 4.15 +/- 0.44 s and 5.04 +/- 0.43 vs 3.87 +/- 0.28 s, respectively, before and after naloxone) but failed to decrease it in rats treated with dexamethasone only (3.88 +/- 0.18 vs 4.34 +/- 0.25 s, before and after naloxone). These observations indicate that gonadal steroids are the most important steroid factors involved in the reaction time to tail immersion in hot water and confirm other reports that the opioid pathways modulating the neuronal circuitry require the presence of these hormones.

Caracterização morfológica dos estádios de desenvolvimento do aparelho reprodutor masculino da rã-touro, Rana catesbeiana, no sistema anfigranja de criação intensiva

The objective of this work was to caracterize the morphological characterization of the development stages of male reproduction apparel of bullfrog Rana catesbeiana from intensive Anfigranja system. During the period of one year, 657 bullfrog males were removed from regrowing and reproduction sections in Anfigranja system to study basic aspects of the reproduction of this specie. The collections were realized monthly and, in that occasion, the body and testicles weights for each animal were recorded and their macroscopic gonadal characteristics, registred. Testicles from 274 males were removed and histologically analyzed. From the macro and microscopic gonadal characteristics, analysis set of the testicles, five stages of gonadal maturation for the male of Rana catesbeiana were determined: juvenile, beginning of maturation, intermediate maturation, advanced maturation and spent.

Reproductive biology of the neotropical superfetaceous Pamphorichthys hollandi (Cyprinodontiformes : Poeciliidae)

We investigated sex ratio, reproductive period, fecundity, and sexual dimorphism of Pamphorichthys hollandi in southeastern Brazil. Reproductive status was identified according to a female's gonads/embryos development scale. of the 613 collected specimens, 373 (60 %) were females and 240 (40 %) males giving a sex ratio of I male: 1.6 female. Sexual dimorphism was evident in respect to body size, body coloration, and anal and pelvic-fin morphologies. The highest proportion of reproductive females was registered in January and February, which represent wet and hot periods. The simultaneous presence of more than one litter at different stages of development within a single female characterized this species as superfetaceous.

Melanocytes in the testes of Eupemphix nattereri (Anura, Leiuperidae): Histological, stereological, and ultrastructural aspects

Ectothermic vertebrates have a well-developed system of melanin-containing cells, which localize in several organs and tissues and compose an extracutaneous pigmentary system. This research aimed at characterizing histological and ultrastructural patterns of pigmented cells in the testes of the anura Eupemphix nattereri (Steindachner, 1963), including the stereological and quantitative evaluation of this cell type in the gonads. Ten adult males were collected in Nova Itapirema, São Paulo, Brazil, and submitted to morphological studies with light and transmission electron microscopy. The testis presents a great number of large cells with many brown granules and long cytoplasmic processes. The pigmented cells found in the testis are structurally similar to melanocytes, characterized by large amounts of melanosomes. The cells may be in intimate contact with the same cell type, with myoid cells surrounded by a large amount of collagen fibers, Leydig cells, and next to fibroblasts. The distribution and amount of extracutaneous melanocytes is variable when other organs and membranes are analyzed, allowing the establishment of species-specific patterns for the extracutaneous pigmentary system.

Estimativa do Tamanho da Primeira Maturação Sexual da Rã - Touro, Rana catesbeiana, no Sistema Anfigranja de Criação Intensiva

The objective of this research was to study the basic aspects of bullfrog reproduction in Anfigranja system from June 1989 to July 1990. For the 1493 animals involved in this experiment (657 males and 836 females) biometrical data were obtained (weight, length and tympanum diameter) and developmental stages of gonads were determined. Female sizes at first maturation were 10,33 cm and 109,78 g and for males it was around 8,09 cm; all males above 45 g were already in the maturation process. The relationship between tympanum diameter and body length (RTC) was considered a good index for male maturation.

Caracterização morfológica dos estádios de desenvolvimento do aparelho reprodutor feminino da rã-touro, Rana catesbeiana, no sistema anfigranja de criação intensiva

The objective of this work was to caracterize the morphological characterization of the development stages of female reproduction apparel of bullfrog Rana catesbeiana from intensive Anfigranja system. During the period of one year, 836 bullfrog females were removed from regrowing and reproduction sections of the Anfigranja system to study the basic aspects of the reproduction of this specie. The collections were realized monthly and, in that occasion, the body and ovary weights for each animal were recorded and their macroscopic gonadal characteristics, registred. The ovaries from 303 females were removed and histologically examined. From the macro and microscopic characteristics analysis set of the ovary, five stages of gonadal maturation for the female of Rana catesbeiana were determined: juvenile, beginning of maturation, intermediate maturation, advance maturation and spent.

Cytogenetical characterization of six orb-weaver species and review of cytogenetical data for Araneidae

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Impact of breed and sex on porcine endocrine transcriptome: a bayesian biometrical analysis

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Anatomy of the male reproductive system of Phrynops geoffroanus (Testudines: Chelidae).

The reproductive system of male Phrynops geoffroanus adults is macroscopically described and the variation in testicular biometry is evaluated. A pair of oval testes is connected by the efferent ductules to the epididymis, which continue as deferent ducts, which emerge in the penis. The volume of the gonads showed the highest averages during spring and summer months. GSI varied significantly throughout the year, with the highest averages observed in the months that correspond to the end of spring and the beginning of summer, when the reproduction of the species takes place, and the lowest averages were seen in winter, suggesting a cyclical testicular activity.

Reproductive biology and moulting cycle of the crab Callinectes ornatus (Decapoda, Portunidae) from the Ubatuba region, Sao Paulo, Brazil

To investigate the reproductive biology of Callinectes ornatus gonadal and moulting cycles were studied over two consecutive years in the Ubatuba region. Six stages of gonadal development were detected in females and four in males. Observations on the number of ovigerous females, on the moulting stages of males and females, and on the percentage of individuals exhibiting mature gonads reveal a continuous reproductive cycle, the stages of which progress at different rates. These data support the hypothesis that C. ornatus shows staggered spawning, with possibly more than one annual reproductive period. A pause in growth before the terminal moult may occur in this species.

Relação peso-comprimento e fator de condição para Cichla cf. ocellaris e Cichla monoculus (Perciformes, Cichlidae) no reservatório de Volta Grande, Rio Grande - MG/SP

The aim of this paper was to analyze the length-weight relationship and the condition factor of two species of cichlids (Cichla cf. ocellaris and Cichla monoculus) (Perciformes, Cichlidae) that were inducted in Volta Grande Reservoir, Rio Grande. There was no difference in the length-weight relationship between the sexes for Cichla cf. ocellaris and Cichla monoculus. The allometric condition factor showed a fall in the spring and another smaller one in the winter. It happens when these fishes change their feeding activity. In the spring all the reproductive behavior are developed and, in the winter, there is a shortage of prey. The variation of the relative condition factor followed the variation of the allometric condition factor due to the low contribution of the gonads weight and the small amount of accumulated fat in the total weight. The length distribution, length-weight relationship and condition factor of these fishes vary in accordance with the time of introduction into the reservoir, the characteristics of the ecosystem as well as the interactions among the species at these sites.

Endocrine Disruptors and Hypothalamic Sexual Differentiation

The so-called endocrine disruptors have been described as compounds which interfere with the estrogen action in their receptors and may exert a crucial role in the development of the reproductive tract and in the brain sexual differentiation. Thus, conducts and/or exposure to these drugs in the perinatal period that apparently do not endanger the neonate may cause side effects. During embrionary development, the gonads, through discharge of a small quantity of reproductive hormones, will guarantee the phenotype of male or female at birth, as well as actuate in specific areas sexual differentiation of the central nervous system. Several experimental models have shown an interference of drugs acting as endocrine disruptors in hypothalamic sexual differentiation. Thus, reproductive function is impaired by exposure to estrogen in the perinatal life of rats and the mechanisms involved in this effect are distinct for males and females. Perinatal exposure to drugs which may be considered endocrine disrupters may induce an incomplete masculinization and defeminization of the central nervous system. Alterations in these processes, if present, generally are perceived only at puberty or adult reproductive life. These later alterations may include anomalies in the process of fertility or in sexual behavior.

Reproductive biology of the shrimp Rimapenaeus constrictus (Decapoda, Penaeidae) in the ubatuba region of Brazil

Sexual maturity, temporal reproductive pattern, and recruitment of juveniles were examined for the shrimp Rimapenaeus constrictus at three different bays in the Ubatuba region (Mar Virado, Ubatuba, and Ubatumirim), State of São Paulo (23°S 45°W). Monthly samples were taken from January 1998 to December 1999. The presence or absence of mating plugs (associated with mating and insemination) and ovarian maturity were used to examine breeding in adult females. The whole sample comprised 3863 females and 1468 males. Estimates of size (carapace length) at the onset of sexual maturity were 7.0 mm and 7.8 mm for males and females, respectively. Higher percentage of females bearing ripe gonads was observed during spring and summer over the course of the study, contrasting to the low proportion in fall 1998 and winter 1999. Juvenile shrimps were sampled year-round. These results suggest a continuous reproductive pattern for R. constrictus. Mating, spawning, and juvenile recruitment took place mostly in shallow waters up to 20-m depths in the study region. Warm to mild temperatures may favour the spawning pattern observed in this species. The classical paradigm of continuous reproduction at lower latitudes, with increased seasonality of breeding period at higher latitudes, seems to apply to this species.