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1.
Nat Commun ; 11(1): 623, 2020 01 30.
Artigo em Inglês | MEDLINE | ID: mdl-32001689

RESUMO

Optical in vivo recordings from freely walking Drosophila are currently possible only for limited behaviors. Here, we expand the range of accessible behaviors with a retroreflective marker-based tracking and ratiometric brain imaging system, permitting brain activity imaging even in copulating male flies. We discover that P1 neurons, active during courtship, are inactive during copulation, whereas GABAergic mAL neurons remain active during copulation, suggesting a countervailing role of mAL in opposing P1 activity during mating.


Assuntos
Copulação/fisiologia , Drosophila/fisiologia , Neuroimagem/métodos , Comportamento Sexual Animal/fisiologia , Comportamento Social , Animais , Encéfalo/metabolismo , Corte/psicologia , Proteínas de Drosophila/metabolismo , Feminino , Neurônios GABAérgicos/metabolismo , Masculino , Neuroimagem/instrumentação , Neurônios/metabolismo , Córtex Olfatório/diagnóstico por imagem
2.
Nature ; 578(7793): 137-141, 2020 02.
Artigo em Inglês | MEDLINE | ID: mdl-31996852

RESUMO

Organisms have evolved diverse behavioural strategies that enhance the likelihood of encountering and assessing mates1. Many species use pheromones to communicate information about the location, sexual and social status of potential partners2. In mice, the major urinary protein darcin-which is present in the urine of males-provides a component of a scent mark that elicits approach by females and drives learning3,4. Here we show that darcin elicits a complex and variable behavioural repertoire that consists of attraction, ultrasonic vocalization and urinary scent marking, and also serves as a reinforcer in learning paradigms. We identify a genetically determined circuit-extending from the accessory olfactory bulb to the posterior medial amygdala-that is necessary for all behavioural responses to darcin. Moreover, optical activation of darcin-responsive neurons in the medial amygdala induces both the innate and the conditioned behaviours elicited by the pheromone. These neurons define a topographically segregated population that expresses neuronal nitric oxide synthase. We suggest that this darcin-activated neural circuit integrates pheromonal information with internal state to elicit both variable innate behaviours and reinforced behaviours that may promote mate encounters and mate selection.


Assuntos
Feromônios/fisiologia , Proteínas/fisiologia , Comportamento Sexual Animal/fisiologia , Animais , Feminino , Masculino , Camundongos , Bulbo Olfatório/fisiologia , Reforço Psicológico
3.
Environ Pollut ; 259: 113883, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-31931411

RESUMO

Artificial Light At Night (ALAN) is an emerging pollution, that dramatically keeps on increasing worldwide due to urbanisation and transport infrastructure development. In 2016, it nearly affected 23% of the Earth's surface. To date, all terrestrial and aquatic ecosystems have been affected. The disruption of natural light cycles due to ALAN is particularly expected for nocturnal species, which require dark periods to forage, move, and reproduce. Apart from chiropterans, amphibians contain the largest proportion of nocturnal species among vertebrates exhibiting an unfavourable conservation status in most parts of the world and living in ALAN polluted areas. Despite the growing number of studies on this subject, our knowledge on the direct influence of nocturnal lighting on amphibians is still scarce. To better understand the consequences of ALAN on the breeding component of amphibian fitness, we experimentally exposed male breeding common toads (Bufo bufo) to ecologically relevant light intensities of 0.01 (control), 0.1 or 5 lux for 12 days. At mating, exposed males took longer than controls to form an amplexus, i.e. to pair with a female, and broke amplexus before egg laying, while controls never did. These behavioural changes were associated with fitness alteration. The fertilisation rate of 5 lux-exposed males was reduced by 25%. Salivary testosterone, which is usually correlated with reproductive behaviours, was not altered by ALAN. Our study demonstrates that ALAN can affect the breeding behaviour of anuran species and reduce one component of their fitness. Given the growing importance of ALAN, more work is needed to understand its long-term consequences on the behaviour and physiology of individuals. It appears essential to identify deleterious effects for animal populations and propose appropriate management solutions in an increasingly brighter world.


Assuntos
Bufo bufo , Luz , Comportamento Sexual Animal , Animais , Bufo bufo/fisiologia , Ecossistema , Feminino , Masculino , Fotoperíodo , Comportamento Sexual Animal/fisiologia , Comportamento Sexual Animal/efeitos da radiação
4.
Bull Entomol Res ; 110(1): 96-105, 2020 Feb.
Artigo em Italiano | MEDLINE | ID: mdl-31190656

RESUMO

Diamides have been used worldwide to manage the diamondback moth (DBM), Plutella xylostella L. (Lepidoptera: Plutellidae), however some strains showed resistance to these molecules. Also, pheromone traps could be used to manage this pest, hence reducing the use of insecticides in the field. Resistant DBM strains may have biological disadvantages in comparison to susceptible strains in areas without sprays, including reduction in fitness or behavioral changes. Therefore, the aim of this study was to investigate whether DBM strains resistant to chlorantraniliprole showed adaptive costs that could alter male attraction to the sex pheromone, in comparison to susceptible strains in the laboratory and semi-field conditions. First, the LC1, LC10, LC25, and LC50 of DBM to chlorantraniliprole were established, which were 0.003, 0.005, 0.007, and 0.011 mg a.i. liter-1, and 5.88, 24.80, 57.22, and 144.87 mg a.i. liter-1 for the susceptible and resistant strains, respectively. Development and reproduction of DBM strains subjected to those concentrations were compared. Later, male response to the sex pheromone was investigated in a Y-tube in the laboratory and in a greenhouse to pheromone traps. Resistant DBM strain showed an adaptive cost in comparison to the susceptible strain that can result in a delay in population growth in the field when selection pressure is absent. Conversely, resistant males have no olfactory response alteration in comparison to susceptible males, consistently at 3 (P = 0.6848) and 7 days (P = 0.9140) after release, suggesting that pheromone traps continue to be a viable alternative to manage DBM in an IPM system.


Assuntos
Adaptação Biológica , Inseticidas , Mariposas/fisiologia , Comportamento Sexual Animal/fisiologia , ortoaminobenzoatos , Animais , Resistência a Inseticidas/fisiologia , Masculino , Atrativos Sexuais , Olfato
5.
Biosci Biotechnol Biochem ; 84(1): 25-30, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31516064

RESUMO

The Japanese orange fly, Bactrocera tsuneonis, infests various citrus crops. While male pheromone components accumulated in the rectal glands are well characterized for Bactrocera, but information regarding the chemical factors involved in the life cycles of B. tsuneonis remains scarce. Herein, several volatile chemicals including a γ-decalactone, (3R,4R)-3-hydroxy-4-decanolide [(3R,4R)-HD], were identified as major components, along with acetamide and spiroketals as minor components in the rectal gland complexes of male B. tsuneonis flies. The lactone (3R,4R)-HD was also identified in female rectal gland complexes. The amount of this compound in mature males was significantly higher than those observed in females and immature males. The lactone (3R,4R)-HD was detected in flies fed with sucrose only, indicating that this lactone is not derived from dietary sources during adulthood, but biosynthesized in vivo. The predominant accumulation of (3R,4R)-HD in mature males also suggests a possible role in reproductive behavior.


Assuntos
Lactonas/química , Glândula de Sal/química , Tephritidae/fisiologia , Acetamidas/síntese química , Acetamidas/química , Animais , Cromatografia Gasosa , Citrus , Dieta , Feminino , Furanos/síntese química , Furanos/química , Japão , Lactonas/síntese química , Masculino , Espectrometria de Massas , Reprodução/fisiologia , Atrativos Sexuais/química , Comportamento Sexual Animal/fisiologia , Compostos de Espiro/síntese química , Compostos de Espiro/química , Sacarose
6.
Zoolog Sci ; 36(6): 504-510, 2019 Dec 09.
Artigo em Inglês | MEDLINE | ID: mdl-31833321

RESUMO

In the traditional view of sexual selection, females are the choosier sex, and males of many species often develop exaggerated ornaments. Recently, however, the evolution and maintenance of female ornaments has also attracted significant attention. In the present study, we examined the function of a female ornament, i.e., red coloration of the area around gill cover, in the context of male mate preferences in the cyprinid fish Puntius titteya. The result of a dichotomous choice experiment showed that males preferred females with redder coloration. Together with the results of a previous study, these findings suggest that males and females in this species mutually select each other based on red coloration. In addition, females with higher color saturation spawned larger eggs. With supplementation of carotenoid-rich foods, females exhibited redder coloration and higher color saturation. These results imply that, by choosing females based on carotenoid-based coloration, males might obtain high quality mates and offspring.


Assuntos
Cyprinidae/fisiologia , Comportamento Sexual Animal/fisiologia , Pigmentação da Pele/fisiologia , Animais , Feminino , Masculino
7.
PLoS One ; 14(12): e0226239, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31841551

RESUMO

Bacteria and other types of microbes interact with their hosts in several ways, including metabolic pathways, development, and complex behavioral processes such as mate recognition. During the mating season, adult males of the lesser long-nosed agave pollinator bat Leptonycteris yerbabuenae (Phyllostomidae: Glossophaginae) develop a structure called the dorsal patch, which is located in the interscapular region and may play a role in kin recognition and mate selection. Using high-throughput sequencing of the V4 region of the 16S rRNA gene, we identified a total of 2,847 microbial phylotypes in the dorsal patches of eleven specimens. Twenty-six phylotypes were shared among all the patches, accounting for 30 to 75% of their relative abundance. These shared bacteria are distributed among 13 families, 10 orders, 6 classes and 3 phyla. Two of these common bacterial components of the dorsal patch are Lactococcus and Streptococcus. Some of them-Helcococcus, Aggregatibacter, Enterococcus, and Corynebacteriaceae-include bacteria with pathogenic potential. Half of the shared phylotypes belong to Gallicola, Anaerococcus, Peptoniphilus, Proteus, Staphylococcus, Clostridium, and Peptostreptococcus and specialize in fatty acid production through fermentative processes. This work lays the basis for future symbiotic microbe studies focused on communication and reproduction strategies in wildlife.


Assuntos
Quirópteros/fisiologia , Microbiota/fisiologia , Comportamento Sexual Animal/fisiologia , Animais , Dorso/microbiologia , Bactérias/genética , Bactérias/isolamento & purificação , Biodiversidade , Quirópteros/microbiologia , DNA Bacteriano/análise , Sequenciamento de Nucleotídeos em Larga Escala , Masculino , México , Microbiota/genética , RNA Ribossômico 16S/análise , RNA Ribossômico 16S/genética , Reprodução/fisiologia
8.
Nat Commun ; 10(1): 4770, 2019 10 18.
Artigo em Inglês | MEDLINE | ID: mdl-31628317

RESUMO

Animals perform or terminate particular behaviors by integrating external cues and internal states through neural circuits. Identifying neural substrates and their molecular modulators promoting or inhibiting animal behaviors are key steps to understand how neural circuits control behaviors. Here, we identify the Cholecystokinin-like peptide Drosulfakinin (DSK) that functions at single-neuron resolution to suppress male sexual behavior in Drosophila. We found that Dsk neurons physiologically interact with male-specific P1 neurons, part of a command center for male sexual behaviors, and function oppositely to regulate multiple arousal-related behaviors including sex, sleep and spontaneous walking. We further found that the DSK-2 peptide functions through its receptor CCKLR-17D3 to suppress sexual behaviors in flies. Such a neuropeptide circuit largely overlaps with the fruitless-expressing neural circuit that governs most aspects of male sexual behaviors. Thus DSK/CCKLR signaling in the sex circuitry functions antagonistically with P1 neurons to balance arousal levels and modulate sexual behaviors.


Assuntos
Proteínas de Drosophila/metabolismo , Drosophila melanogaster/metabolismo , Proteínas do Tecido Nervoso/metabolismo , Neurônios/metabolismo , Neuropeptídeos/metabolismo , Oligopeptídeos/metabolismo , Fatores de Transcrição/metabolismo , Animais , Animais Geneticamente Modificados , Nível de Alerta/fisiologia , Comunicação Celular/genética , Proteínas de Drosophila/genética , Drosophila melanogaster/genética , Drosophila melanogaster/fisiologia , Feminino , Locomoção/fisiologia , Masculino , Proteínas do Tecido Nervoso/genética , Neurônios/citologia , Neuropeptídeos/genética , Oligopeptídeos/genética , Comportamento Sexual Animal/fisiologia , Transdução de Sinais/genética , Sono/fisiologia , Fatores de Transcrição/genética
9.
Behav Processes ; 168: 103944, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31472169

RESUMO

In the terrestrial crustacean Armadillidium vulgare, a large size range exists in natural populations within which males and females could potentially mate. Because of continuous growth far beyond sexual maturity, the largest individuals can be nearly ten times the live mass of the smallest sexually mature individuals. In this study, we explored the influence of male and female body mass on the mating behaviour and success. Starting with a representative panel of males and females in which females are significantly larger than males in average, we followed the sexual behaviour of 23 groups of 20 mixed-sex virgin animals under conditions comparable with natural field situation during the early breeding season. We found a correlation between paired individuals showing an assortative pairing. During pairing male stimulates female and duration of stimulation is determinant for pairing follow-up: efficient stimulation is correlated with female size and not with male size. In consequence, pairs in mating show a reversed size dimorphism between male and female where female are about 20% smaller. Largest females were not mated. During copulation behaviour, the quantity of sperm transferred is positively correlated with copulation duration. Stored sperm can be used for immediate breeding by the female and stored in the spermatheca for future breeding. The last option allows to largest females in the field to continue breeding without additional mating, avoiding the lack of availability of large males able to stimulate them efficiently.


Assuntos
Tatus/crescimento & desenvolvimento , Peso Corporal , Impulso (Psicologia) , Comportamento Sexual Animal , Animais , Tamanho Corporal , Correlação de Dados , Feminino , Masculino , Fatores Sexuais , Comportamento Sexual Animal/fisiologia , Contagem de Espermatozoides
10.
Behav Processes ; 167: 103939, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31421152

RESUMO

In spiders, pheromones are known to be responsible for attracting the opposite sex, eliciting male searching and courtship behaviors, as well as for synchronizing potential mates in space and time. Most spiders are cannibalistic and aggressive. Thus, early recognition of a female as a possible mate is essential for males, who may suffer high energetic or reproductive costs to the extreme of losing all fitness opportunities. In Acanthogonatus centralis Goloboff 1995, a mygalomorph spider, what female signs might be triggering male courtship behavior remain unknown, as well as whether males can discriminate between females. The aims of the present work were (1) establishing whether males can detect the presence of females using airborne and silk-borne signals and (2) determining whether males can discriminate the reproductive status and body condition of females. We found no evidence that airborne pheromones play a role in the sexual communication of A. centralis, but silk-bound contact signals function as a female advertisement. Also, this is the first study that demonstrates that male mygalomorph spiders can discriminate between different signals on silk through direct contact, showing a preference for unmated females.


Assuntos
Comunicação Animal , Feromônios , Comportamento Sexual Animal/fisiologia , Aranhas/fisiologia , Animais , Feminino , Masculino , Reprodução/fisiologia , Seda
11.
Zoology (Jena) ; 135: 125690, 2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-31383295

RESUMO

In this study, we investigated the reproductive biology of the small lizard Eurolophosaurus nanuzae based on evidence of sperm storage by females and variations of the renal sexual segment (RSS) in males. We found a remarkable occurrence of crypts containing bundles of sperm and secretions in the epithelium of E. nanuzae oviducts. The chemical composition of the secretions associated with the sperm within the crypts was similar to secretions from the oviductal epithelium, which suggests that females can produce substances involved in the maintenance of stored sperm. Female sperm storage does not occur over the span of years for long-term reproduction; the majority of females with stored sperm occurred during the peak and late periods of the reproductive season. We discuss this result in relation to post-copulatory sexual selection strategies in the context of sperm competition for restricted successful fertilisation. In males, testicular activity was continuous, while RSS activity varied seasonally, in synchrony with female reproductive activity. Throughout the reproductive season, the RSS was hypertrophied, with maximum activity during the peak of the reproductive season. The lowest RSS activity occurred when females were not reproductive (non-reproductive season). Considering that RSS secretions are essential for reproduction, an absence or reduction of these secretions during the non-reproductive season may imply the reduced functionality of sperm during this period. Since sperm production continues throughout the whole reproductive cycle in E. nanuzae males, RSS activity could be an important indicator of reproduction, beyond testicular activity.


Assuntos
Lagartos/anatomia & histologia , Lagartos/fisiologia , Animais , Feminino , Gônadas , Masculino , Oviductos/anatomia & histologia , Reprodução/fisiologia , Comportamento Sexual Animal/fisiologia , Espermatozoides
12.
Nat Commun ; 10(1): 3818, 2019 08 23.
Artigo em Inglês | MEDLINE | ID: mdl-31444351

RESUMO

The ecological contexts that promote larger brains have received considerable attention, but those that result in smaller-than-expected brains have been largely overlooked. Here, we use a global sample of 2062 species to provide evidence that metabolic and life history tradeoffs govern the evolution of brain size in birds and play an important role in defining the ecological strategies capable of persisting in Earth's most thermally variable and unpredictable habitats. While some birds cope with extreme winter conditions by investing in large brains (e.g., greater capacity for planning, innovation, and behavioral flexibility), others have small brains and invest instead in traits that allow them to withstand or recover from potentially deadly events. Specifically, these species are restricted to large body sizes, diets consisting of difficult-to-digest but readily available foods, and high reproductive output. Overall, our findings highlight the importance of considering strategic tradeoffs when investigating potential drivers of brain size evolution.


Assuntos
Aclimatação/fisiologia , Evolução Biológica , Aves/fisiologia , Encéfalo/anatomia & histologia , Tamanho do Órgão/fisiologia , Distribuição Animal/fisiologia , Animais , Clima , Ecossistema , Comportamento Alimentar/fisiologia , Estações do Ano , Comportamento Sexual Animal/fisiologia
13.
Behav Processes ; 167: 103921, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31376418

RESUMO

In a mating system in which females are monandrous and males are polygynous, females may incur a risk by mating with males with possible sperm depletion following consecutive matings. Here, we examined the effects of male mating history on male mating success and female reproductive fitness in the wolf spider Pardosa pseudoannulata by performing mating trials and sperm counting experiments. Results showed that male mating history had a significant negative impact on subsequent copulation success but had little effect on courtship duration and courtship intensity. In addition, neither male courtship intensity nor morphological measurements of males and females had significant effects on male mating success. Furthermore, male mating history had no obvious impact on the fecundity of inseminated females, with no significant differences observed in the oviposition rate of females, the numbers and the carapace width of the second-instar spiderlings between treatments. Results showed that the number of sperm decreased significantly after mating but could be replenished, with no significant differences observed between groups in which males had rested for 7 d. These findings suggest that polygynous male spiders may recharge their sperm during the mating season, but how females differentiate the mating status of males remains unknown.


Assuntos
Fertilidade/fisiologia , Comportamento Sexual Animal/fisiologia , Aranhas/fisiologia , Animais , Feminino , Masculino , Oviposição/fisiologia , Reprodução/fisiologia , Espermatozoides/fisiologia
14.
Behav Processes ; 168: 103940, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31446194

RESUMO

Pheromones play a pivotal role in intra-species communication for reproduction and social behavior in a variety of mammals, such as boars. For boars, saliva is a rich source of pheromones, however, the identification of additional sources and relative abundance of pheromones in various body fluids of sows is also essential to understand the reproductive behaviors of pigs. The present study was designed to identify the source(s) of pheromones in sows. We collected urine, feces, saliva and cervical mucus/vaginal wash samples from sows at pre-estrus, estrus and post-estrus phases, and from gilts and exposed boars to each of these potential sources of pheromones. All the boars tested spent more time sniffing and hyper-salivating in response to urine from sows in estrus than that from sows not in estrus. The sniffing behavior of boars towards estrus samples differed from that towards the samples from non-estrus sows (P < 0.005) and gilts (P < 0.001). Further, hypersalivation behavior of boars differed between estrus samples and gilt samples (P < 0.05) and estrus samples compared to pre-estrus samples (P < 0.05). This is an indication that pheromones are abundant in the estrus samples. We conclude that urine of estrus sows can be a rich source of pheromones and the same can be used to identify, purify and characterize novel pheromone molecules.


Assuntos
Estro/fisiologia , Feromônios/fisiologia , Comportamento Sexual Animal/fisiologia , Sus scrofa/fisiologia , Animais , Feminino , Feromônios/urina , Suínos , Desmame
15.
Adv Physiol Educ ; 43(4): 458-466, 2019 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-31460777

RESUMO

In this teaching laboratory, students design and perform an experiment to determine estrogen's role in imprinting the brain of neonatal rats to express either male or female sexual behavior. A discussion question is provided before the laboratory exercise in which each student is asked to search the literature and provide written answers to questions and to formulate an experiment to test the role of estrogen in imprinting the mating behavior of male and female rats. Students discuss their answers to the questions in laboratory with the instructor and design an experiment to test their hypothesis. In male rats, testosterone is converted by aromatase expressed by neurons in the brain to estrogen. Production of estrogen in the brain of neonatal rats imprints mating behavior in males, where a lack of estrogen action in the brain imprints female sexual behavior. The model involves administering exogenous testosterone to imprint male behavior in female pups or administration of an aromatase inhibitor (letrozole) or an estrogen receptor antagonist (ICI 182,780) to imprint female sexual behavior in male pups. In the model, litters of neonatal pups are treated with either carrier (control), testosterone propionate, aromatase inhibitor (letrozole), or an estrogen receptor antagonist (ICI 182,780) postnatally on days 1 and 3. Alteration of mating behavior is evaluated through the numbers of males and females that breed and establish pregnancy. This is a very simple protocol that provides an excellent experiment for student discussion on the effects of hormone action on imprinting brain sexual behavior.


Assuntos
Encéfalo/fisiologia , Hormônios Esteroides Gonadais/fisiologia , Fisiologia/educação , Comportamento Sexual Animal/fisiologia , Animais , Avaliação Educacional/métodos , Feminino , Humanos , Masculino , Vias Neurais/fisiologia , Ratos , Maturidade Sexual/fisiologia
16.
PLoS One ; 14(7): e0218778, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31291268

RESUMO

Social learning has important ecological and evolutionary consequences but the role of certain factors, such as social rank, neophobia (i.e., avoidance of novel stimuli), persistence, and task-reward association, remain less understood. We examined the role of these factors in social learning by captive coyotes (Canis latrans) via three studies. Study 1 involved individual animals and eliminated object neophobia by familiarizing the subjects to the testing apparatus prior to testing. Studies 2 and 3 used mated pairs to assess social rank, and included object neophobia, but differed in that study 3 decoupled the food reward from the testing apparatus (i.e., altered task-reward association). For all three studies, we compared performance between coyotes that received a demonstration from a conspecific to control animals with no demonstration prior to testing. Coyotes displayed social learning during study 1; coyotes with a demonstrator were faster and more successful at solving the puzzle box but did not necessarily use the same modality as that observed to be successful. In study 2, there was no difference in success between treatment groups but this is likely because only one coyote within each pair was successful so successful coyote results were masked by their unsuccessful mate. In study 3, there was no difference in success between treatment groups; only two coyotes, both dominant, hand-reared males with demonstrators were able to perform the task. However, coyotes with a demonstrator were less neophobic, measured as latency to approach the object, and more persistent, measured as time spent working on the apparatus. Social rank was the best predictor of neophobia and persistence and was also retained in the best model for time to eat inside the apparatus, a post-trial measurement of object neophobia. These results suggest coyotes are capable of social learning for novel tasks but social rank, neophobia, and persistence influence their social-learning capabilities. This study contributes to understanding the mechanisms underlying how animals gain information about their environment.


Assuntos
Coiotes/psicologia , Comportamento Imitativo/fisiologia , Resolução de Problemas/fisiologia , Aprendizado Social/fisiologia , Animais , Coiotes/fisiologia , Feminino , Masculino , Observação , Recompensa , Comportamento Sexual Animal/fisiologia , Comportamento de Utilização de Ferramentas/fisiologia
17.
PLoS One ; 14(7): e0218069, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31265478

RESUMO

Seahorses are considered one of the most iconic examples of a monogamous species in the animal kingdom. This study investigates the relationship between stocking density and mating and competitive behavior from the context of the field biology of the dwarf seahorse, Hippocampus zosterae (Jordan & Gilbert). Animals were housed in 38 liter tanks at a range of densities and sex ratios (from 2-8 animals per tank), and their reproductive and other social behaviors were monitored from tank introduction through copulation. At low tank densities and even sex ratios but comparatively high field densities, frequency of both mating and competitive behaviors was low in trials. A higher level of males in tanks across all densities increased competition, activity levels, and aggression leading to egg transfer errors and brood expulsion, resulting in lower reproductive success. Across seahorse species, mean and maximum wild densities were consistently lower than those used in ex situ breeding, with adult sex ratios that were significantly female biased. However, significant variation exists in wild seahorse densities across species, with higher densities detected in focal/mark recapture studies and on artificial habitat structures than reported with belt transect sampling techniques. Interchange of knowledge gained in both aquarium and wild contexts will allow us to better understand the biology of this genus, and improve reproduction in captivity. Interpreting ex situ reproductive behaviors of seahorses within various densities reported from natural populations will help us predict the impact of conservation efforts and increase the likelihood of long-term persistence of populations for this threatened genus.


Assuntos
Ecossistema , Comportamento Sexual Animal/fisiologia , Smegmamorpha/fisiologia , Animais , Feminino , Masculino , Dinâmica Populacional
18.
Behav Processes ; 166: 103896, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31271768

RESUMO

Male-female interactions in several group living organisms, including some fish species tend to be dynamic and play a key role in determining their mating and courtship behavior. Laboratory-bred zebrafish (Danio rerio) strains are one of the most widely used model systems in various fields of biology. While research on wild zebrafish behavior is gaining ground, our knowledge about their mating ecology and mating strategies is still limited. We investigated diel temporal patterns in inter-sex dyadic interactions among wild zebrafish and the occurrence of behavioral dimorphism in their interactive behaviors. We observed randomly paired male and female individuals at three distinct time intervals (early morning, morning and afternoon sessions) in the day and collected occurrence data for six discrete inter-individual interactive behaviors that were associated with mating, aggression, and display. We used generalized linear mixed models to examine the effect of time, sex of the individual and presence of oviposition substrate on these behavioral traits. We found a higher incidence of mating-associated behavior during the early parts of the day which declined by the afternoon. These mating-associated behaviors were also dependent on the presence of gravel substrate for egg-laying compared to other behaviors. This work is the first of its kind that details patterns in behavioral dimorphism between sexes in zebrafish. Our results throw light on the complex dynamics of male-female interactions in a group living externally fertilizing species and can have implications in designing experiments involving behavioral testing of zebrafish which is increasingly being done in toxicological studies and laboratory breeding.


Assuntos
Agressão/fisiologia , Comportamento Animal/fisiologia , Caracteres Sexuais , Comportamento Sexual Animal/fisiologia , Animais , Feminino , Masculino , Oviposição/fisiologia , Reprodução/fisiologia , Peixe-Zebra
19.
PLoS Genet ; 15(7): e1008309, 2019 07.
Artigo em Inglês | MEDLINE | ID: mdl-31344027

RESUMO

Males of the Drosophila melanogaster mutant croaker (cro) generate a polycyclic pulse song dissimilar to the monocyclic songs typical of wild-type males during courtship. However, cro has not been molecularly mapped to any gene in the genome. We demonstrate that cro is a mutation in the gene encoding the Calmodulin-binding transcription factor (Camta) by genetic complementation tests with chromosomal deficiencies, molecular cloning of genomic fragments that flank the cro-mutagenic P-insertion, and phenotypic rescue of the cro mutant phenotype by Camta+-encoding cDNA as well as a BAC clone containing the gene for Camta. We further show that knockdown of the Camta-encoding gene phenocopies cro mutant songs when targeted to a subset of fruitless-positive neurons that include the mcALa and AL1 clusters in the brain. cro-GAL4 and an anti-Camta antibody labeled a large number of brain neurons including mcALa. We conclude that the Camta-encoding gene represents the cro locus, which has been implicated in a species-specific difference in courtship songs between D. sechellia and simulans.


Assuntos
Calmodulina/metabolismo , Proteínas de Drosophila/genética , Drosophila melanogaster/fisiologia , Comportamento Sexual Animal/fisiologia , Transativadores/genética , Animais , Encéfalo/metabolismo , Corte , Proteínas de Drosophila/metabolismo , Teste de Complementação Genética , Masculino , Especificidade da Espécie , Transativadores/metabolismo , Vocalização Animal
20.
PLoS One ; 14(7): e0219518, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31344046

RESUMO

Using a well-established model species for demographic, behavioural and aging research, the Mediterranean fruit fly (Ceratitis capitata), we explored whether nutritional stress early in adult life affects the sexual performance and survival in older ages. To do so we established two different protein starvation (PS) protocols that included the elimination of proteinaceous diet either before or after sexual maturity of male medflies. The frequency of sexual signalling and the age of death were daily recorded. Sexual signalling is directly related with male mating success in this model system. PS early in adult life results in high mortality rates (similar to sugar-only fed males), which are gradually restored in more advanced ages. Provision of a proteinaceous diet following early-life PS increases straightaway male sexual signalling to levels similar with those having continuous access to proteinaceous diet. Switching diet regimes from a protein-free to a protein-rich one progressively compensates mortality rates. Apparently, males prioritize sexual signalling over lifespan. PS after attaining sexual maturity significantly reduces both longevity and sexual performance. Access to protein only early in life is insufficient to support lifetime energy-consuming behaviours such as sexual signalling. Continuous access to a proteinaceous diet determines both lifetime sexual performance and longevity. Early in life PS males prioritize the allocation of nutritional elements, when available, in sexual activities over soma-maintenance.


Assuntos
Ceratitis capitata/fisiologia , Proteínas de Insetos/metabolismo , Longevidade/fisiologia , Comportamento Sexual Animal/fisiologia , Animais , Dieta , Feminino , Estimativa de Kaplan-Meier , Masculino , Modelos de Riscos Proporcionais
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