Copulatory behaviour and the process of intromission in Anastrepha ludens (Diptera: Tephritidae)

Complex genitalia occur in many arthropods and in some species extreme female morphologies lead to serious mechanical difficulties for males. Tephritid flies offer examples of such complex genitalia. Because of their economic importance and the extensive use of sterile male releases for tephritid control in Texas and Mexico, studies have been done on various aspects of their basic reproductive biology, but the process of intromission has received little attention. The distiphallus of the male of Anastrepha ludens is complex. One membranous sac on the distiphallus is capable of rhythmic cycles of inflation and deflation. Inflations of the sac near the base of the distiphallus probably help propel the aedeagus deeper into the female along with stiffening of the basiphallus and may drive the genital rod (which does not transfer sperm) into the ventral receptacle. We were unable to establish an association between some of the behaviours displayed by males during mating and intromission process. Rev. Biol. Trop. 59 (1): 291-297. Epub 2011 March 01.

En muchos artrópodos, se observan genitales complejos; la morfología extrema en las hembras podría conducir a serios problemas mecánicos para los machos (Kamimura & Matsuo 2001). Las moscas tefrítidas tienen ejemplos de tales órganos genitales complejos. Debido a su importancia económica y la amplia utilización de machos estériles para el control biológico en Texas y México, se han realizado estudios sobre diversos aspectos de su biología reproductiva, pero el proceso de penetración ha recibido muy poca atención. El distiphallus de los machos de Anastrepha ludens es complejo. Un saco membranoso en el distiphallus es capaz de realizar ciclos rítmicos de inflación y deflación. El inflado de la bolsa cerca de la base del distiphallus, junto con la rigidez del basiphallus probablemente ayuda a impulsar el edeagus más profundamente en la hembra y orientar la vara genital (que no transfiere esperma) en la región del receptáculo ventral. No pudimos establecer una asociación entre algunas de las conductas mostradas por los machos durante el apareamiento y el proceso de intromisión.

Rat dorsal prostate is necessary for vaginal adhesion of the seminal plug and sperm motility in the uterine horns

The rat prostate comprises dorsal, ventral and lateral lobes that are morphologically and biochemically distinct. Lesions to these structures are expected to affect the quality of the ejaculate and male fertility. In experiment 1, we analyzed ejaculate parameters of males that had chemical lesions of the dorsal or ventral lobes. At pre-lesion and at 5 and 20 days post-lesion males were mated, and after ejaculation, seminal fluid and seminal plug were obtained from the mated females. In experiment 2, the ventral lobes were ablated, and the ejaculate was analyzed. In experiment 3, the fertility of males with chemically-lesioned dorsal lobes or ablation of the ventral lobes was evaluated. Chemical lesion of the dorsal lobe prevented the adhesion of the seminal plug to vaginal walls. When these males were tested at 5-days postlesion, no sperm were found in uterus, and at 20-days post-lesion, the few sperm encountered showed slow progressive motility. None of the females that mated with dorsal lobe-lesioned males became pregnant. However, chemical lesion or ablation of the ventral lobes did not affect ejaculate or fertility. Our results indicate that the dorsal prostatic lobes are indispensable for reproductive success in males, and define parameters of ejaculate with which fertility can be estimated.

Protective effect of maternal prenatal melatonin administration on rat pups born to mothers submitted to constant light during gestation

We studied the effects of adverse conditions such as constant light (LL) on the circadian rhythm of malate (MDH, EC 1.1.1.37) and lactate (LDH, EC 1.1.1.27) dehydrogenase activities of the testes of male Wistar rats on postnatal day 28 (PN28), anxiety-like behavior (elevated plus-maze test) at PN60 and sexual behavior at PN120. The rats were assigned to mother groups on day 10 of pregnancy: control (12-h light/dark), LL (light from day 10 to 21 of pregnancy), and LL+Mel (LL and sc injection to the mothers of a daily dose of melatonin, 1 mg/kg body weight at circadian time 12, from day 17 to 21 of pregnancy). LL offspring did not show circadian rhythms of MDH (N = 62) and LDH (N = 63) activities (cosinor and ANOVA-LSD Fisher). They presented a 44.7 percent decrease in open-arm entries and a 67.9 percent decrease in time (plus-maze test, N = 15, P < 0.001, Mann-Whitney U-test and Kruskal-Wallis test), an increase in mounting (94.4 percent), intromission (94.5 percent) and ejaculation (56.6 percent) latencies (N = 12, P < 0.01, Mann-Whitney U-test and Kruskal-Wallis test) and lower numbers of these events (61, 59 and 73 percent, respectively; P < 0.01, N = 12) compared to controls. The offspring of the LL+Mel group presented MDH and LDH circadian rhythms (P < 0.05, N = 50, cosinor and ANOVA-LSD Fisher), anxiety-like and sexual behaviors similar to control. These findings supported the importance of the melatonin signal and provide evidence for the protective effects of hormones on maternal programming during gestation. This protective action of melatonin is probably related to its entrainment capacity, favoring internal coupling of the fetal multioscillatory system.

PATRONES DE ALIMENTACIÓN, SUEÑO Y ACTIVIDAD REPRODUCTIVA EN JERBOS DE MONGOLIA (Meriones unguiculatus) / PATTERNS OF FEEDING, SLEEP AND REPRODUCTIVE BEHAVIOR IN MONGOLIAN GERBILS (Meriones unguiculatus)

Los jerbos de Mongolia son roedores utilizados como excelente modelo biológico. A pesar de esto, su clasificación como especie diurna, nocturna o crepuscular no ha sido clara. Los experimentos que se presentan en este artículo evaluaron patrones de alimentación, sueño-actividad y actividad reproductiva y copulativa en condiciones de luz/oscuridad 12:12 en Jerbos de Mongolia. Los resultados de los experimentos sugieren un patrón nocturno de comportamiento en estos roedores.

Mongolian Gerbils are often used as a biological model, but it remains unclear whether these rodents display nocturnal, diurnal, or crepuscular patterns of behavior. The experiments presented below studied patterns of sleep-activity, feeding, and reproductive behavior under 12:12 light dark cycles. All data from these experiments suggest a nocturnal pattern of behavior in these rodents.

Genitalic stridulation during copulation in a species of crane fly, Tipula (Bellardina) sp. (Diptera: Tipulidae) / Estridulación genital durante la cópula en una especie de mosca grulla, Tipula (Bellardina) sp. (Dípteros: Tipulidae)

The male genitalia of many animal groups have elaborate and species-specific forms. One hypothesis  to explain why this is so is that male genitalia function as stimulatory devices that are under sexual selection by cryptic female choice. This report is based on a videotaped observation of a single male of an unidentified species of Tipula (Bellarina) from San José Province, Costa Rica. A male crane fly stridulated (produced vibrations) during copulation using sustained and stereotyped movements of file and scraper structures on his genitalia. Males of related species have similar file and scraper structures on their genitalia, suggesting that they probably also stridulate during copulation. Rev. Biol. Trop. 57 (Suppl. 1): 251-256. Epub 2009 November 30.

Un macho de Tipula (Bellardina) sp. estriduló (produjo vibraciones) por medio de movimientos estereotipados de estructuras de sus órganos genitales durante varios minutos de la cópula. Los machos de algunas especies relacionadas poseen estructuras similares, lo cual sugiere que también estridulan durante la cópula.

Histological and histochemical characterization of the secretory cells of Choeradoplana iheringi Graff, 1899 (Platyhelminthes: Tricladida: Terricola)

The present study aims at providing a detailed description of the histology, as well as the first histochemical characterization, of the secretory cells of the epidermis, pharynx, and copulatory organs of Choeradoplana iheringi, in order to give further support to studies on the physiology of these organs. The secretory cells are distinguished on the basis of secretion morphology and its staining properties, using trichrome methods and histochemical reactions. Four cell types open through the epidermis of Ch. iheringi, three of them secreting basic protein and a fourth containing glycosaminoglycan mucins. The epidermal lining cells store glycogen. In the pharynx, four secretory cell types were distinguished. Two types produce glycoprotein, a third type secretes basic protein, and another one produces glycosaminoglycan mucins. In the male copulatory organs, the prostatic vesicle receives four secretory cell types containing basic protein, except for one type which produces glycoprotein. The two secretory cell types opening into the male atrium secrete, respectively, glycoprotein, and glycosaminoglycan mucins. In the female copulatory organs, the female atrium and its proximal diverticulum, the vagina, receive two types of secretory cells producing, respectively, basic protein and glycosaminoglycan mucins. Another secretory cell type constitutes the so-called shell glands which open into the common glandular duct, secreting basic protein. The lining cells of the male and female atria produce a mucous secretion containing glycosaminoglycans. In addition, the lining epithelium of the female atrium presents an apical secretion of a proteic nature. The occurrence of a kind of spermatophore is reported for the first time for a species of Choeradoplana. This structure is located in the male or female atria in different specimens, and characterized by erythrophil, xanthophil, and/or mixed secretions associated with sperm.

O presente estudo tem por objetivo fornecer detalhada descrição da histologia e a primeira caracterização histoquímica das células secretoras da epiderme, da faringe e do aparelho reprodutor de Ch. iheringi, visando a propor estudos da fisiologia desses órgãos. As células secretoras foram diferenciadas com base na morfologia da secreção e em sua coloração, com métodos tricrômicos e reações histoquímicas. Quatro tipos de células secretoras desembocam na epiderme de Ch. iheringi, sendo três com secreção protéica básica e uma do tipo mucoso, contendo glicosaminoglicanas. As células de revestimento que compõem a epiderme armazenam glicogênio. Na faringe, quatro tipos de células secretoras são observadas: duas produzem secreção de natureza glicoprotéica, uma apresenta secreção protéica básica e uma secreta glicosaminoglicanas. No aparelho copulador masculino, em sua vesícula prostática desembocam quatro tipos de células secretoras, as quais contêm secreção protéica básica, excetuando uma cuja secreção é de natureza glicoprotéica. O átrio masculino recebe a desembocadura de dois tipos de células secretoras, um tipo contendo secreção glicoprotéica e outro, glicosaminoglicanas. No aparelho copulador feminino, o átrio feminino e seu divertículo ental, a vagina, recebem a desembocadura de dois tipos de células secretoras, que produzem, respectivamente, proteína básica e glicosaminoglicanas. Um outro tipo de célula secretora constitui as chamadas glândulas da casca, que desembocam no ducto glandular comum e secretam proteína básica. As células de revestimento dos átrios masculino e feminino produzem secreções mucosas constituídas por glicosaminoglicanas. O epitélio de revestimento do átrio feminino apresenta, ainda, um tipo diferenciado de secreção protéica acumulada apicalmente. A ocorrência de um tipo de espermatóforo é registrada pela primeira vez para uma espécie de Choeradoplana. Tal estrutura foi observada em três espécimes, ocorrendo no átrio masculino ou feminino, sendo caracterizada pela associação de espermatozóides com secreções eritrófilas, xantófilas e/ou mistas.

Why do male Xylographus contractus Mellié (Coleoptera: Ciidae) present abdominal fovea? Evidence of sexual pheromone secretion / Por que machos de Xylographus contractus Mellié (Coleoptera: Ciidae) apresentam fóvea abdominal? Evidências de secreção de feromônio sexual

Most male ciids present a fovea in the first urosternite. We tested two alternative hypotheses for the function of male abdominal fovea in Xylographus contractus Mellié: (i) the fovea secretes sexual pheromone, and (ii) the fovea secretes aggregation pheromone. For this, 59 specimens were submitted, separately, to two stimuli (fovea extracts and control) in an y-shaped glass olfactometer. For the analyses, we considered the 47 individuals that moved toward one of the longer olfactometer branches. The probability of moving toward the fovea extract was greater for females than for males (chi2 = 3.94, P = 0.047). The proportion of males that moved toward any of the olfactometer branches was the same (chi2 = 0.29, P = 0.59). We concluded that the male's abdominal fovea secretes a sexual pheromone and that there is no aggregation pheromone being secreted by this structure. We suggested that this sexual pheromone is used for short-range communication, acting in pre-copulatory courtship.

A maioria dos machos de ciídeos possuem uma fóvea no primeiro urosternito. Foram testadas duas hipóteses alternativas para explicar a função da fóvea abdominal em machos de Xylographus contractus Mellié: (i) a fóvea secreta feromônio sexual, e (ii) a fóvea secreta feromônio de agregação. Para isso, avaliou-se a resposta de 59 indivíduos, separadamente, a dois estímulos olfativos (extrato da fóvea e controle) em olfatômetro tipo Y. Nas análises, consideraram-se as respostas dos 47 indivíduos que se dirigiram a um dos braços do olfatômetro. A probabilidade de se deslocar em direção ao extrato de fóvea foi maior para fêmeas do que para machos (chi2 = 3,94, P = 0,047). A proporção de machos que se dirigiram para cada um dos braços do olfatômetro foi a mesma (chi2 = 0,29, P = 0,59). A fóvea abdominal dos machos secreta feromônio sexual, não sendo secretado nenhum feromônio de agregação por essa mesma estrutura. Sugere-se que o feromônio sexual seja usado em comunicação a curta distância, mediando mecanismos pré-copulatórios.

SCANNING ELECTRON MICROSCOPIC OBSERVATIONS ON THE COPULATORY SPICULES OF THE MALE NECATOR AMERICANUS AND ANCYLOSTOMA DVODENALE / 中国寄生虫学与寄生虫病杂志

Scanning electron microscopic observations were made on the morphological structures of the two copulatory spicules of the male Necator americanus and Ancylostoma duodenale. In both species,one of the two copulatory spicules was in the shape of a concave groove and the other, in the shape of an oblate tube. Owing to the difference in the concavity of the groove shaped copulatory spicule between the two species as shown by the cross sections, Necator americanus usually appear to have only one copulatory spicule whereas Ancylostoma duodenale usually show two separate copulatory spicules in appearance (Figs 1 -10).