Fiber quality and fertility in male alpacas in the Cusco region of Peru.

Introduction: High testosterone levels might be associated with coarser fiber in alpacas, affecting fiber quality. In the husbandry systems employed in the Andes, males with higher libido might have an increased frequency of successful matings than males with lower libido. This study aimed to determine some of the factors affecting fiber quality in Peruvian alpacas and to evaluate the association between fiber quality and male mating behavior. Methods: The study population consisted of 189 adult male alpacas at La Raya, Cusco, Peru, at 4,400 m above sea level, belonging to the National University of San Marcos, Lima, and the National University of San Antonio Abad of Cusco. Fiber samples were collected from male alpacas in September 2015; body condition score (BCS) was evaluated. After washing and drying, the fiber samples were analyzed using an Optical Fiber Diameter Analyser 2000; linear regression analysis between predictor variables (location of alpacas, age, BCS, and fiber color) and fiber quality outcomes was conducted. Fertility data were available only for some males belonging to San Marcos University, consisting of hand-written records from the breeding season January to April 2015; individual fertility quotients were calculated for each male. Results: Age was associated with fiber quality, young alpacas having the finest fibers (p < 0.05). An increased BCS was associated with increased fiber length, fiber diameter and spinning fineness, but decreased comfort factor (p < 0.05). White fibers were thinner (p = 0.05) than colored fibers, with lower comfort factor and spinning fineness. A significant association between the fertility quotient and fiber curvature was observed (p = 0.018). Discussion: These results suggest that careful selection of breeding individuals and attention to husbandry could result in improved fiber quality among alpaca herds in Peru. However, it would be advisable to increase the number of males studied, using more reliable methods for evaluating male fertility and pregnancy diagnosis than were available for this study.

Lateralized Movements during the Mating Behavior, Which Are Associated with Sex and Sexual Experience, Increase the Mating Success in Alphitobius diaperinus (Coleoptera: Tenebrionidae).

In the present study, we explored the effects of displacement directionality in mating behavior (i.e., lateralized and non-lateralized movements) on mating success (i.e., copulation occurs) and efficiency (i.e., time length at which copulation is achieved), and its association with sex and sexual experience in A. diaperinus. To do so, we carried out mating experiments and recorded the behavior of the mating pair during the whole mating sequence (i.e., precopulatory and copulatory phases). During the precopulatory phase, independently of sex and sexual experience, all beetles performed non-lateralized (i.e., backside or frontside) approaches; however, only sexually experienced beetles showed lateralized approaches (i.e., right-side and left-side). Notably, experienced males exhibited greater mating success than virgin males. After the approach, both virgin and experienced males displayed lateralized and non-lateralized mounts on the females with distinct mating success. Regardless of their sexual experience, 100% of successful mating attempts were achieved when males mounted from the females' right side. Furthermore, the development of lateralized approaches and mounts reduces the time of mating sequence span compared with non-lateralized behaviors. We highlight the importance of lateralization in mating behavior and sexual experience to achieve higher mating success, addressing a potential learning ability of beetles based on experience.

Chemical Signals Associated With Gender and Sexual Experience Affect Mating and the Attractiveness of the Poultry Pest, Alphitobius diaperinus (Coleoptera: Tenebrionidae).

Alphitobius diaperinus is one of the most significant pests in the poultry industry. Identifying the role of self-produced chemical signals can help control it. Here, we exposed adults to the olfactory signals of other adults of similar and different genders (either males or females) and sexual experiences (i.e., virgin and experienced) to assess their long-range attractiveness and, at short-range, their mating behavior responses (i.e., touching, mounting, and copulation). In olfactometric experiments, our results indicate that adults are attracted to the olfactory signals of other male adults, independently of gender, or sexual condition, indicating the presence of generalized long-range attractive signals, in contrast to female signals, can be both factor-dependent. However, in mating experiments, virgin males developed more robust mating responses (i.e., they mount and copulate longer with females) compared to sexually experienced males, even though they both have similar precopulatory behavioral responses (i.e., time of antennal and leg touching). These results address the importance of short-range chemical signals in eliciting copulation. Furthermore, when virgins of both genders were tested, their mating responses were significantly longer than any other pair combination, indicating that sexual experience also affects mating behavior. Chemical analyses of adult extracts showed that sexual experience, but not gender, is linked to differences in chemical profiles of adults, primarily involved in short-range signaling. These findings provide new insights into the attractiveness and mating responses of A. diaperinus and the role of sexual experience in shaping the behavior and chemical profile of insects that mate multiple times during their lifetime.

Influence of exogenous corticosterone on testicular function and mating behavior of Nigerian indigenous cocks.

In bridging the knowledge gap on stress physiology of Nigerian indigenous chickens, this study investigated the effect of exogenous corticosterone (eCORT) as stress inducing agent on the testicular function and mating behavior of Nigerian indigenous cocks. Twenty-four (24) cocks and one hundred and forty four (144) hens (mating ratio of 1 cock: 6 hens) were grouped into four and assigned to each of the four eCORT treatments (0, 2, 4 and 6 mgeCORT/KgBW) daily for 14 days. Semen samples were collected on days 0, 7 and 14 and analyzed for semen volume (SV), progressive sperm motility (PSM), membrane integrity (MI) and sperm abnormality (SA). Mating behaviors were monitored on days 3, 5 and 8. Blood samples, for hormonal (Luteinizing Hormone (LH), Follicle Stimulating Hormone (FSH) Testosterone (TEST) and stress analysis (heterophil/lymphocyte ratio, H/L) were collected from brachial vein on days 7 and 14. On day 15, cocks were euthanized and testes harvested for histomorphometry. Data were analyzed using multivariate analysis, one-way ANOVA and Kruskal-Wallis tests all in SPSS 23. Administration of 4 mgeCORT/KgBW declined (P<0.05) PSM while 4 mgeCORT/KgBW and 6 mgeCORT/KgBW cocks had reduced (P<0.05) SV and MI with increased SA. Compared to baseline values, progressive sperm motility of cocks administered 6 mgeCORT for 7 and 14 days decreased (P<0.05) by 57.5% and 52.4%, respectively. Exogenous CORT had no significant (P>0.05) influence on the mating behaviors, H/L ratio, FSH and TEST. However, 2 mgeCORT/KgBW enhanced LH levels. Administration of eCORT did not affect the testicular epithelial height and seminiferous tubular diameter. In conclusion, optimal stress induced by eCORT impaired semen quality but with less impact on reproductive hormones, H/L and mating behaviors of intensively raised Nigerian indigenous cocks.

From copula to fertilization: The reproduction of primitive crab Hypoconcha parasitica (Linnaeus, 1763) (Podotremata: Dromiidae).

This study describes the mating behavior of Hypoconcha parasitica under laboratory conditions highlighting the spermathecal morphology and focusing on the seminal fluid storage and release of spermatozoa. The pairs were kept in aquaria where the mating behavior was recorded and described. The spermathecae of the female were analyzed using scanning electron microscopy, X-ray micro-CT, histology, and histochemistry. No pre- or post-copulatory mate guarding was observed in H. parasitica. The sperm transfer occurred with each pair maintaining the protection shield (bivalve shell) on their dorsum. The pair of spermathecae is covered exclusively by the cuticle, following the Podotremata pattern. Many muscle fiber bundles are attached to the cuticular wall facing toward the cephalothorax cavity, especially covering the lateral and slightly dorso-anterior region toward the apodeme of Sternite 7. The spermathecal organization indicates that the process of sperm release during fertilization occurs through muscular action exerted by the female on the wall of the chamber. Thus, the musculature distribution in Hypoconchinae distinguishes them from described for other Podotremata such as Homolidae, which shows the musculature associated with the spermathecae aperture. Like the Homolidae, the first pleopod in H. parasitica seems to take part in the transfer/ movement of spermatozoa and oocytes between the sternum and abdomen, which forms a temporary chamber where fertilization occurs. In conclusion, the spermathecal morphology and associated structures bring new insights to the mechanisms involved in the sperm storage and fertilization of primitive crabs and how the Dromiidae spermatheca perform a new pattern among the poorly studied Podotremata.

Influence of exogenous corticosterone on testicular function and mating behavior of Nigerian indigenous cocks

In bridging the knowledge gap on stress physiology of Nigerian indigenous chickens, this study investigated the effect of exogenous corticosterone (eCORT) as stress inducing agent on the testicular function and mating behavior of Nigerian indigenous cocks. Twenty-four (24) cocks and one hundred and forty four (144) hens (mating ratio of 1 cock: 6 hens) were grouped into four and assigned to each of the four eCORT treatments (0, 2, 4 and 6 mgeCORT/KgBW) daily for 14 days. Semen samples were collected on days 0, 7 and 14 and analyzed for semen volume (SV), progressive sperm motility (PSM), membrane integrity (MI) and sperm abnormality (SA). Mating behaviors were monitored on days 3, 5 and 8. Blood samples, for hormonal (Luteinizing Hormone (LH), Follicle Stimulating Hormone (FSH) Testosterone (TEST) and stress analysis (heterophil/lymphocyte ratio, H/L) were collected from brachial vein on days 7 and 14. On day 15, cocks were euthanized and testes harvested for histomorphometry. Data were analyzed using multivariate analysis, one­way ANOVA and Kruskal-Wallis tests all in SPSS 23. Administration of 4 mgeCORT/KgBW declined (P0.05) influence on the mating behaviors, H/L ratio, FSH and TEST. However, 2 mgeCORT/KgBW enhanced LH levels. Administration of eCORT did not affect the testicular epithelial height and seminiferous tubular diameter. In conclusion, optimal stress induced by eCORT impaired semen quality but with less impact on reproductive hormones, H/L and mating behaviors of intensively raised Nigerian indigenous cocks.(AU)

Analysis of Honeybee Drone Activity during the Mating Season in Northwestern Argentina.

Males in Hymenopteran societies are understudied in many aspects and it is assumed that they only have a reproductive function. We studied the time budget of male honey bees, drones, using multiple methods. Changes in the activities of animals provide important information on biological clocks and their health. Yet, in nature, these changes are subtle and often unobservable without the development and use of modern technology. During the spring and summer mating season, drones emerge from the hive, perform orientation flights, and search for drone congregation areas for mating. This search may lead drones to return to their colony, drift to other colonies (vectoring diseases and parasites), or simply get lost to predation. In a low percentage of cases, the search is successful, and drones mate and die. Our objective was to describe the activity of Apis mellifera drones during the mating season in Northwestern Argentina using three methods: direct observation, video recording, and radio frequency identification (RFID). The use of RFID tagging allows the tracking of a bee for 24 h but does not reveal the detailed activity of drones. We quantified the average number of drones' departure and arrival flights and the time outside the hive. All three methods confirmed that drones were mostly active in the afternoon. We found no differences in results between those obtained by direct observation and by video recording. RFID technology enabled us to discover previously unknown drone behavior such as activity at dawn and during the morning. We also discovered that drones may stay inside the hive for many days, even after initiation of search flights (up to four days). Likewise, we observed drones to leave the hive for several days to return later (up to three days). The three methods were complementary and should be considered for the study of bee drone activity, which may be associated with the diverse factors influencing hive health.

Different mating contexts lead to extensive rewiring of female brain coexpression networks in the guppy.

Understanding the basis of behavior requires dissecting the complex waves of gene expression that underlie how the brain processes stimuli and produces an appropriate response. In order to determine the dynamic nature of the neurogenomic network underlying mate choice, we use transcriptome sequencing to capture the female neurogenomic response in two brain regions involved in sensory processing and decision-making under different mating and social contexts. We use differential coexpression (DC) analysis to evaluate how gene networks in the brain are rewired when a female evaluates attractive and nonattractive males, greatly extending current single-gene approaches to assess changes in the broader gene regulatory network. We find the brain experiences a remarkable amount of network rewiring in the different mating and social contexts we tested. Further analysis indicates the network differences across contexts are associated with behaviorally relevant functions and pathways, particularly learning, memory and other cognitive functions. Finally, we identify the loci that display social context-dependent connections, revealing the basis of how relevant neurological and metabolic pathways are differentially recruited in distinct social contexts. More broadly, our findings contribute to our understanding of the genetics of mating and social behavior by identifying gene drivers behind behavioral neural processes, illustrating the utility of DC analysis in neurosciences and behavior.

The size of signal detection and emission organs in a synchronous firefly: sexual dimorphism, allometry and assortative mating.

The size of the organs responsible for emitting and detecting sexual communication signals is a likely target for selection. Communication via bioluminescent signals in synchronous fireflies is a promising model to test hypotheses regarding differences between males and females in the effect of the size of signal emission and detection organs on fitness components. Synchronous firefly species congregate in large numbers during the mating season, displaying bioluminescent signals aimed at potential mates during relatively short nightly periods. Operational sex ratios are male-biased and, thus, the so-called typical sex roles (indiscriminate males and choosy females) are expected to evolve. We studied the synchronous firefly Photinus palaciosi, a species that during the mating season congregates in forests of central Mexico offering a magnificent natural show that attracts numerous tourists. P. palaciosi females have reduced wings (brachyptery) and cannot fly. Our field study tested the hypothesis that the male-biased operational sex ratio and the short daily mating period result in strong male-male competition that selects for males with larger lanterns and larger eyes, and against male mate choice, whereas female-female mate competition is absent and, thus, no selection on lantern or eye size is expected. Even though lantern, eye or body size do not predict the probability of being found in copula for either sex, sexual dimorphism in these features, along with allometric slopes of lantern size and assortative mating in terms of relative lantern size, support not only the hypothesis of intense sexual selection among males, but the possibility of subtle mechanisms of sexual selection among females. Trade-offs between investment in signaling (lanterns) versus detection (eyes) structures, or with pressures different from sexual selection such as those imposed by predators, are also likely to be important in shaping the evolution of sexual signaling in these fireflies.

Influence of Sexual Genotype and Gender Self-Perception on Sociosexuality and Self-Esteem among Transgender People.

Empirical data from studies with both heterosexual and homosexual individuals have consistently indicated different tendencies in mating behavior. However, transgenders' data are often overlooked. This exploratory study compared levels of sociosexuality and self-esteem between transgenders and non-transgender (cisgender) individuals. The aim was to verify whether either sexual genotype or gender self-perception had more influence on the examined variables in transgenders. Correlations between self-esteem and sociosexuality levels were also investigated. The sample consisted of 120 Brazilian individuals (51 transgenders) from both sexes. Sociosexuality scores indicated mostly sex-typical patterns for transgenders of both sexes across the construct's three dimensions (behavior, attitude, and desire), except for female-to-male transgenders' behavioral sociosexuality. Unique associations between the dimensions of sociosexuality were found for transgender participants. No differences in self-esteem were observed and no correlations between self-esteem and sociosexuality were found. The results suggest that transgenders' sociosexuality is largely influenced by their sexual genotype despite their incongruent gender self-perception and that the relationships between behavior, attitude, and sociosexual desire are different from those observed in cisgenders.

Asymmetric evolutionary responses to sex-specific selection in a hermaphrodite.

Sex allocation theory predicts that simultaneous hermaphrodites evolve to an evolutionary stable resource allocation, whereby any increase in investment to male reproduction leads to a disproportionate cost on female reproduction and vice versa. However, empirical evidence for sexual trade-offs in hermaphroditic animals is still limited. Here, we tested how male and female reproductive traits evolved under conditions of reduced selection on either male or female reproduction for 40 generations in a hermaphroditic snail. This selection favors a reinvestment of resources from the sex function under relaxed selection toward the other function. We found no such evolutionary response. Instead, juvenile survival and male reproductive success significantly decreased in lines where selection on the male function (i.e., sexual selection) was relaxed, while relaxing selection on the female function had no effect. Our results suggest that most polymorphisms under selection in these lines were not sex-antagonistic. Rather, they were deleterious mutations affecting juvenile survival (thus reducing both male and female fitness) with strong pleiotropic effects on male success in a sexual selection context. These mutations accumulated when sexual selection was relaxed, which supports the idea that sexual selection in hermaphrodites contributes to purge the mutation load from the genome as in separate-sex organisms.

Diferencias en la conducta de emparejamiento entre mujeres jóvenes universitarias de Santiago de Chile en relación con el consumo de píldoras anticonceptivas orales / Differences in mating behavior among university young women of Santiago de Chile in relation to the consumption of oral contraceptive pills

Durante los últimos años en Chile se ha detectado una masificación en el uso de anticonceptivos orales. Sin embargo, en Chile y al igual que en casi todos los países latinoamericanos prácticamente no se han investigado sus implicancias sobre la conducta humana. Específicamente, este estudio evaluó el impacto del uso de estos anticonceptivos sobre la conducta de emparejamiento en un grupo de 164 mujeres jóvenes universitarias, con una media de edad igual a 19 años y provenientes de cuatro universidades chilenas. Para ello se utilizó la adaptación chilena del Cuestionario de Componentes del Valor de Pareja que está compuesto por 22 ítems que se responden en una escala Likert de siete valores. Los resultados señalan diferencias entre las mujeres que consumen píldoras anticonceptivas (PA) y las que no lo hacen. Las consumidoras presentan los mayores valores del índice general del cuestionario sobre los componentes del valor de pareja y las subescalas de historia de relaciones de pareja, apreciación desde el sexo opuesto y apariencia. Estos resultados indican que las mujeres consumidoras de la PA se autoperciben y creen que el sexo contrario las evalúa como atractivas y muestran una vida sexual más diversificada, no mostrando diferencias en los otros aspectos relevantes para el valor de pareja no vinculados centralmente al atractivo físico. En definitiva, los resultados parecen indicar que el consumo de anticonceptivos hormonales no modifica la conducta social y parental de las mujeres, aunque su uso parece estar asociado con una mayor autopercepción de atractivo y mayor diversidad sexual.

Oral contraceptives, also known as birth control pills (PAs from now on), have been available on the world market for five decades. At present, the use of PA is massifier worldwide, being consumed by more than 100 million women on the planet. In recent years, in Latin America has been detected a dramatic increase in the use of oral contraceptives, and Chile is not the exception. In this sense, it is probable that the increase in the consumption of PAs in Chile is linked to the increase of women who decide to pursue higher studies and to develop professional careers. Concurrently, a wide field of research has been focused on the physiological and psychological effect of the consumption of oral contraceptives on human behavior, being mating behavior one of the main topics of research. However, in Chile as in most Latin American countries there is a lack of studies on the implications of the consumption of oral contraceptives on human behavior. In the present study, we investigated in a group of 164 university young women (Mean ± Standard Deviation: 19.27± 2.88 years) of Chile the impact of the use of oral contraceptives on mating behavior. Accordingly, we have applied a validated psychometric test to assessed mate value, one of the more relevant components of mating behavior i.e., the Mate Value Questionnaire. Mate value can be defined as a construct that incorporates a number of physical, psychological, and social dimensions that are related to an individual's ability to find, attract, and successfully retain a partner. This questionnaire is composed by 22 items and 7 subscales that are answered in a Likert Scale of 7 values. The Mate Value Questionnaire showed a high reliability (α = .85). According with previous studies that showed a decrease in sexual satisfaction and desire on women that consume oral contraceptives, we predicted a decrease of mating behavior and, then, a decrease on Mate Value for those women that use oral contraceptives. This effect was expected for all subscales of this questionnaire with the exception of relationship history subscale since women that consume oral contraceptives reported to have more diverse sexual partners on previous studies. The results show differences between women who use oral contraceptives (n = 87 women: 19.60 ± 2.89 years) in comparison to those who do not (n = women: 18.90 ± 2.84 years). However, the differences were, in general, opposed to our expectations being the consumers of oral contraceptives who presented the highest values of the general index of the Mate Value Questionnaire, and, concretely, for the subscales of relationship history, views of the opposite sex, and looks. In addition, we have failed into found any differences between groups in subscales that were not associated to physical appearance, such as wealth, sociality and fear of failure. The results suggest that the use of hormonal contraceptives does not modify the social and parental behavior of the women, although their use seems to be associated with a greater self-perception of attractiveness and greater diversity in sexual life. This study provides new information that will increase the understanding and discussion about the hypothetical effect that would or would not, the consumption of the PA on the pairing behavior. It is important to point out that the field of research on changes in the sexual preferences of women, derived from hormonal states, is in an important discussion process. Therefore, we believe that it is critical to carry out research in the future in order to elucidate the real robustness of this phenomenon, improving our understanding about the behavioral effects of consuming oral contraceptives.

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.

Behavioral Analysis and Ethogram of Mating in the Wasp Sphex latreillei (Lepeletier) (Hymenoptera: Crabronidae).

The present study reevaluates mating in Sphex latreillei (Lepeletier) based on the analysis of 69 filmed reproductive interactions from a population in central Chile. Behaviors recorded before, during, and after copulation were analyzed through Markov chains, identifying statistically significant behavioral transitions that are summarized in a mating ethogram. The results suggest that females exercise choice either during copulation by the means of an internal courtship, or via a post-copulation selection. Both types of inter-sexual selection proposed would explain, in both female and male, the dynamics of a sexual behavior crucial for a reproductive success.

Multiple Paternity in the Norway Rat, Rattus norvegicus, from Urban Slums in Salvador, Brazil.

The Norway rat, Rattus norvegicus, is one of the most important pest species globally and the main reservoir of leptospires causing human leptospirosis in the urban slums of tropical regions. Rodent control is a frequent strategy in those settings to prevent the disease but rapid growth from residual populations and immigration limit the long-term effectiveness of interventions. To characterize the breeding ecology of R. norvegicus and provide needed information for the level of genetic mixing, which can help identify inter-connected eradication units, we estimated the occurrence of multiple paternity, distances between mothers and sires, and inbreeding in rats from urban slum habitat in Salvador, Brazil. We genotyped 9 pregnant females, their 66 offspring, and 371 males at 16 microsatellite loci. Multiple paternity was observed in 22% (2/9) of the study litters. Of the 12 sires that contributed to the 9 litters, we identified 5 (42%) of those sires among our genotyped males. Related males were captured in close proximity to pregnant females (the mean inter-parent trapping distance per litter was 70 m, ±58 m SD). Levels of relatedness between mother-sire pairs were higher than expected and significantly higher than relatedness between all females and non-sire males. Our findings indicate multiple paternity is common, inbreeding is apparent, and that mother-sire dyads occur in close proximity within the study area. This information is relevant to improve the spatial definition of the eradication units that may enhance the effectiveness of rodent management programs aimed at preventing human leptospirosis. High levels of inbreeding may also be a sign that eradication efforts are successful.

Outbreeding and lack of temporal genetic structure in a drone congregation of the neotropical stingless bee Scaptotrigona mexicana.

Drone aggregations are a widespread phenomenon in many stingless bee species (Meliponini), but the ultimate and proximate causes for their formation are still not well understood. One adaptive explanation for this phenomenon is the avoidance of inbreeding, which is especially detrimental for stingless bees due to the combined effects of the complementary sex-determining system and the small effective population size caused by eusociality and monandry. We analyzed the temporal genetic dynamics of a drone aggregation of the stingless bee Scaptotrigona mexicana with microsatellite markers over a time window of four weeks. We estimated the drones of the aggregation to originate from a total of 55 colonies using sibship re-construction. There was no detectable temporal genetic differentiation or sub-structuring in the aggregation. Most important, we could exclude all colonies in close proximity of the aggregation as origin of the drones in the aggregation, implicating that they originate from more distant colonies. We conclude that the diverse genetic composition and the distant origin of the drones of the S. mexicana drone congregation provides an effective mechanism to avoid mating among close relatives.

Effects of D-004, a lipid extract of the fruit of the Cuban royal palm (Roystonea regia) or the lipidosterolic extract of saw palmetto (Serenoa repens) on the sexual activity in male rats: A controlled, experimental study.

BACKGROUND: The etiology of benign prostatic hyperplasia (BPH) is not completely understood, but hormonal changes in aging men seem to be pivotal. Dihydrotestosterone, a potent, active metabolite of testosterone, is formed by the enzymatic action of prostate 5α-reductase and causes cell growth and hyperplasia. Consistent with this action, male sexual dysfunction has been clinically documented to be among the drug-related adverse events associated with 5α-reductase inhibitors. The lipidosterolic extract of saw palmetto (LESP) fruit (Serenoa repens) has been used to treat BPH. D-004, a lipid extract of Roystonea regia Royal palm fruit, has been found to prevent prostatic hyperplasia induced by testoste-rone in rodents and to competitively inhibit prostate 5α-reductase activity in vitro. OBJECTIVE: The purpose of this study was to assess the effects of D-004 and LESP, administered as single or repeated doses, on the sexual activity in male rats. METHODS: This controlled, experimental study was conducted at the Pharmacology Department, Centre of Natural Products, National Centre for Scientific Research, Havana City, Cuba. Adult male Wistar rats weighing 250 to 300 g were randomized into 5 groups: 2 groups treated orally with D-004 (400 and 800 mg/kg); 2 groups treated orally with LESP (400 and 800 mg/kg); and 1 control group orally administered a water vehicle. Sexual activity behavior (the number of mounts and intromissions, mount latency, and intromission latency) was assessed during 2 observation periods: 90 minutes after the initial dose and at the end of the 30-day treatment. Latency was defined as time elapsed between the first mount and intromission. RESULTS: A total of 50 rats (mean [SD] age, 10 [3] weeks; mean [SD] weight, 295 [10] g) were included in the experiment. There were no significant difterences in the mean number of mounts, intromissions, mount latency, or intromission latency in the groups treated with single or repeated doses of D-004 or LESP (400 and 800 mg/kg) compared with the controls. There was also no between-group difterence in mating behavior among the active treatment groups. All rats survived up to study completion, with normal behavior (weight gain, food intake, daily observations, without any sign of toxicity). There were no observable adverse events during the study. CONCLUSIONS: D-004 and LESP administered as a single dose or repeated doses for 30 days did not significantly affect male rat sexual activity behavior compared with a vehicle control group.

Field observations of mating behavior in the neck-banded snake Scaphiodontophis annulatus (Serpentes: Colubridae)

We observed the mating behavior of the neck-banded snake Scaphiodontophis annulatus (a common species of colubrid in the South Pacific of Costa Rica) in the pre-montane wet forest of Las Cruces Biological Station (San Vito de Java, Costa Rica). Three S. annulatus were observed during courtship between 10-12 AM in a patch of primary forest. The two males were observed to interact with the female, but not signs of male-male agonistic interactions were observed. Their behavior includes grabbing and holding the female, copula, and biting during the copula.

El comportamiento de apareamiento es descrito para la serpiente Scaphiodontophis annulatus, una especie de colúbrido común en el Pacífico sur de Costa Rica. El comportamiento incluye capturar y sujetar a la hembra, mordiscos durante la cópula y coito. Dos machos fueron observados al interactuar con una sola hembra, pero no se detectó señales de interacciones antagónicas macho-macho.

Courtship behavior and spawning of the hairy blenny Labrisomus nuchipinnis (Labrisomidae) in southeastern Brazil

Labrisomus nuchipinnis is a diurnal bottom-dwelling sit-and-wait carnivorous fish that inhabits holes and rifts of rocky areas in tropical shallow waters. Here we report on the courtship behavior and spawning of this hairy blenny in southeastern Brazil, with a detailed description and comparison with other Blennioidei. Labrisomus nuchipinnis is a territorial species that was observed courting with more than one female, and presenting a well defined pattern cycle related to reproductive behavior and paternal egg care. Adhesive demersal eggs are laid on small algae-covered rocks at sites with increased current velocity within the male's territory, which may enable higher egg survivorship and shorter developmental time.

Labrisomus nuchipinnis é um peixe bentônico e carnívoro de hábitos diurnos, que espreita suas presas e que habita tocas e frestas de ambientes rochosos em águas rasas tropicais. Registramos o comportamento de corte e desova deste amborê no sudeste do Brasil, descrevendo-o em detalhe e comparando-o com os de outros Blennioidei. Labrisomus nuchipinnis é uma espécie territorial que foi observada em corte com mais de uma fêmea, apresentando uma seqüência cíclica padrão relacionada ao comportamento reprodutivo, e cuidado paternal para com os ovos. Os ovos demersais adesivos são depositados em pequenas rochas cobertas por algas, em locais de elevada hidrodinâmica, localizados dentro do território do macho, o que deve proporcionar uma maior taxa de sobrevivência dos filhotes e menor tempo de desenvolvimento dos embriões.