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1.
Whereas mating behaviors and social structure have been studied extensively in monogamous hermaphroditic gobiid species, such studies are relatively limited for polygamous gobiid species. To investigate the reproductive strategy of polygamous gobies, mating groups of the common fusegoby Fusigobius neophytus were observed on reefs of Kuchierabu-jima Island, southern Japan. Males established mating nests on flat-rock surfaces within their territorial home ranges on sandy rubble flats. Females maintained independent home ranges outside the male home ranges during nonreproductive periods, but they shifted their home ranges to overlap with male ranges and actively visited male mating nests during their reproductive periods (1–3 days at ca. 7-day intervals). Females often changed mates during their serial mating. The mating system used by the common fusegoby fits with the definition of male-territory-visiting polygamy. The sex ratio within the study population was female-biased. Nest-holding males were significantly larger than females and were polygynous (mating with up to eight females). These characteristics fit well with the prediction of protogyny by the size-advantage model. Some of the females were observed to undergo functional sex changes to nest-holding males. In addition, small floating males demonstrated sneaking behavior. None of the floating males were derived from females that had changed sex, suggesting a diandric life-history pathway for F. neophytus.  相似文献   

2.
In the two-spotted spider mite Tetranychus urticae (Acari: Tetranychidae), because only the first mating results in fertilisation, adult males guard quiescent deutonymph females, the stage immediately before adult emergence. Previous studies showed that T. urticae males prefer to guard older rather than younger females. However, as previous experimental designs have included uncertain factors, findings have not always been sufficiently rigorous. Therefore, we reexamined whether T. urticae males discriminate between the females closest to becoming receptive and younger females. One male was introduced onto leaf squares with two differently aged quiescent deutonymph females, with time lags between the females of 3, 6, 12 or 23 h, and whether the older or younger female was guarded was recorded. When the time lags between the females were 3, 6 or 12 h, males showed no preferences. Males preferred older females over younger ones only when the time lag was 23 h. Under non-choice conditions, fewer males guarded the 23-h younger females than other older females, suggesting that the attractiveness of the younger females is weaker than older females. Our results are not fully consistent with previous studies; T. urticae males do not obviously discriminate between females closest to becoming receptive and younger females.  相似文献   

3.
Behavioral interactions between individuals of the same sex can affect the outcome of intersexual selection. For this reason, intrasexual selection is oftentimes examined independently from intersexual selection in studies aimed at understanding mating behaviors. However, a more complete understanding of sexual selection effects within a population can only come from exploring both intrasexual and intersexual selection and the potential interactions between the levels of selection. Association preferences in male and female Etheostoma fonticola do not reveal a size preference for same sex or opposite-sex individuals. However, male-male interactions may influence female choice in E. fonticola. We examined whether male E. fonticola that differ in body size exhibit differences in agonistic behaviors and mating success. Larger males do exhibit higher rates of aggressive behaviors and smaller males, in turn, exhibit more defensive behaviors. However, differences between larger and smaller males in male-male interactions did not translate into differences in spawning success. These results suggest that male size influences dominance relationships in E. fonticola but not mating success. There were also no differences between large and small males in mating attempts, which could be an outcome of the year-round breeding season found in this species, females laying eggs singly, or males fertilizing eggs individually.  相似文献   

4.
The objective of this work was to evaluate the reproductive behavior and response of Elasmopalpus lignosellus (Zeller) males to calling females. Frequency of mating was recorded in couples during the first 7 days of the adult stage. Calling behavior of females was observed during the first 4 days of the adult stage and responses of males, in the same age intervals, to calling females were recorded in wind tunnel bioassays. The maximum number of matings occurred when the couple was between 24 and 48 h old. The scotophase period significantly influenced mating behavior, which peaked between 6 and 8 h of darkness and the mean mating duration was 93.9 ± 4.2 min. Calling females, when evaluated in a wind tunnel, attracted significantly more males than in bioassays with clean air (control). The number of individuals in calling behavior was significantly lower for females that were between 0 to 24 h old compared to the other females evaluated, but this did not influence male response. A lower proportion of males between 48 to 72 h old responded to calling females and these responses were delayed in comparison with males of other ages (0 to 24, 24 to 48, and 72 to 96 h old). These results indicate that the age of E. lignosellus males influences the response to conspecific calling females.  相似文献   

5.
Many species of the butterfly genus Phengaris are regarded as endangered in many parts of their distribution. Several species are also widely distributed across northern China. Due to land use change and overgrazing, their habitats are declining and many patches have been lost. This paper investigates the distribution and habitats of the Chinese Phengaris species (of the subgenus Maculinea). Shrub-grassland near forests seem the most frequent habitat for Phengaris, while flat open grasslands are mostly over-grazed and thus survival for Phengaris butterflies there seems difficult. Throughout Europe, P. teleius is an endangered species, while there is still no information on its status in China. To improve the knowledge on the population ecology of P. teleius, its population structure, adult behaviour and movement were studied through mark–release–recapture methods in the Qinling Mountains of Taibai County. Eight grassland patches which were potentially suitable were found in the area in 2013. In total, 480 individuals (274 females) were marked, resulting in an overall recapture rate of 16 %. The average daily population size was 44 butterflies (±23 SD) during the adult flight period. Sixty-seven percent of the females and 38 % of the males moved less than 50 m, and 17 % of recaptured females and 38 % of males moved more than 200 m. The mean movement distance was 107 ± 177 m for males and 182 ± 122 m for females. The majority of the recaptures (86 %) were made within the patches, only a few individuals (14 %) moved between patches. Due to human disturbance and destruction, all of the eight potentially suitable patches are becoming smaller and increasingly isolated, thus these populations of P. teleius may face an increasing risk of extinction, which may well be a tip of the iceberg of habitat loss and fragmentation of P. teleius in Taibai County and possibly beyond. Hence we hope our initial study of P. teleius could have positive impacts on the conservation of Phengaris butterflies in China.  相似文献   

6.
Hypoaspis larvicolus (Acari: Laelapidae) (first report from Turkey) occurred together with Sancassania polyphyllae (Acari: Acaridae) on the larvae of the scarab beetle, Polyphylla fullo (Coleoptera: Scarabaeidae), that were feeding on the roots of strawberry in Aydin, Turkey. Laboratory studies were conducted to (1) observe whether H. larvicolus feeds and completes its life cycle on the various stages of S. polyphyllae or other astigmatid mites, such as Acarus siro, Carpoglyphus lactis and Tyrophagus putrescentiae (Acaridae), and to determine its population growth when feeding on these prey, and (2) to determine development periods, longevity and fecundity of H. larvicolus feeding on C. lactis. Hypoaspis larvicolus females did not feed on S. polyphyllae, but fed, developed and reproduced when A. siro, C. lactis or T. putrescentiae were provided as prey. Hypoaspis larvicolus is larviparous as well as oviparous. The female lays eggs or gives birth to larvae. If a female gives birth to a larva, it is attached under the female’s venter for 1–2 days, a phenomenon recorded for the first time in Hypoaspis; in fact, for the first time in mites. The results of the population growth experiments revealed that H. larvicolus feeding on C. lactis produced the highest number of eggs, juveniles and adults. The developmental periods of H. larvicolus feeding on C. lactis at life-cycle path I (larva to adult) and II (egg to adult) were 12.2?±?0.3 and 15.6?±?0.6 days (females) and 19.5?±?0.2 and 20.9?±?0.4 days (males), respectively. Longevity of females versus males of H. larvicolus was 120.6?±?7.2 versus 91.6?±?13.1 days (life cycle I) and 110.0?±?27.7 versus 118.3?±?10.9 days (life cycle II), respectively.  相似文献   

7.
Andes virus (AND) is a hantavirus hosted by the sigmodontine rodent Oligoryzomys longicaudatus in southern Argentina, where it is responsible for most cases of hantavirus pulmonary syndrome (HPS). Our study provides data about the spatial variation in abundance of the rodent host of AND hantavirus. We report results of a longitudinal study performed in a locality of the Andean region of Chubut Province. From November 2003 (spring) to July 2006 (winter), O. longicaudatus was the most common species captured (63%) and it showed significant differences in abundance among habitats and seasons. Most antibody-positive rodents were O. longicaudatus (9.2%), followed by A. longipilis (3.6%) and A. olivaceus (1.5%). The highest number of antibody-positive animals was observed for males that belonged to the heaviest mass classes. Antibody-positive O. longicaudatus were more abundant in brush habitats. We found low richness of rodents and abundance of O. longicaudatus in areas affected by anthropogenic activity. The infection seems to be regionally persistent, but the risk to humans in a landscape would be localized. To develop accurate models for predicting HPS outbreaks, further research is needed to characterize rodent movement patterns across the landscape.  相似文献   

8.
The behavior of polar deep-sea nekton is very poorly known. To obtain insight into mating behavior of the abundant and ecologically important sub-Antarctic deep-sea squid Onykia ingens, our goals were to (1) quantify spermatophore production; (2) determine the preferred location for spermatangia deposition; (3) investigate whether male and female O. ingens mate with multiple mates; and (4) discuss the location of implanted spermatangia in light of mating behavior and egg fertilization. Toward this end, we examined male and female O. ingens specimens from Falkland Island and New Zealand waters. Male O. ingens store up to 198 spermatophores (mean 103 ± 61; n = 12) in their reproductive system, which are produced over a period of considerable somatic growth (200–400 mm ML), and which may have a considerable size range. Males insert their long extendible terminal organ in the mantle cavity of the female, potentially through the funnel, to deposit spermatophores in one or more of four regions on the female’s body. Most implanted spermatangia (52.5 %) were found in the funnel region, but many were also found inside the mantle cavity closer to the oviducts. Males with longer terminal organs therefore may be able to position closer to the oviducts where fertilization chances are higher than for spermatangia located in the funnel region. The number of implanted spermatangia per individual female (4–60, mean 29 ± 20; n = 24), the multiregional spermatangia deposition, and the different outer appearance of spermatangia, suggested that females have multiple mating events. Since males produce more spermatophores (up to 200) than the number of spermatangia in one region (<60), it is likely that males too mate with more than one female. We show how quantitative assessment of reproductive characteristics can provide insight into the reproductive behavior of deep-sea species for which in situ observations are currently lacking.  相似文献   

9.
We investigated factors which may determine realised paternity following multiple mating in a promiscuous ladybird Harmonia axyridis (Pallas) (Coleoptera: Coccinellidae), namely the mating order and ability of males of different morphs to fertilize females. In experiments using males of two colour morphs, we found that the first male had a reproductive advantage over the second male (sperm precedence P2 = 0.38). Males of the melanic morph spectabilis had a reproductive advantage over males of the semi-melanic morph axyridis (P2 = 0.35). Analysis of paternity using microsatellites applied to young larvae, which avoids possible differential mortality of progeny, confirmed the precedence of the first male and higher paternity rate of colour morphs that are more frequent in the wild. Hatchability of eggs increased from 65% after the first mating to 85% after the second mating delayed by five days. Average duration of mating was 157 min and did not differ between the first and second mating and between the colour morphs of males.  相似文献   

10.
As an initial contribution to understanding the adaptive value of behavioral and life-history strategies, the life cycle and mating behavior of an unstudied species of tephritid fruit fly in the genus Rhagoletis are characterized for the first time. Over a 9-month fruiting period, a small proportion of Solanum appendiculatum Dunal (< 10 %) was found to be infested with a single larva of Rhagoletis solanophaga (Hernández & Frías). The average duration of R. solanophaga lifecycle (c.a. 140 days from egg laying to death of adults) exceeded the three month fruitless period. Additionally, R. solanophaga is capable of exploiting Solanaceous plants in at least two genera. These features could have selected for a non-diapausing species of Rhagoletis, a genus where most species are univoltine. Nevertheless, some individuals in the population became dormant. As other members of the genus, R. solanophaga exhibited a resource defense mating system with forced copulations and multiple mating. Both males and females could be highly promiscuous and individual mating success exhibited a wide range of outcomes. Regardless of mating success, mated females stored similar amounts of sperm in two spherical spermathecae. Long copulations were observed, perhaps functioning as a form of mate guarding with probable disadvantages for females. We outline hypotheses and opportunities for future comparative studies examining sperm competition and mate guarding.  相似文献   

11.
Male Ilyoplax pusilla perform a waving display, a simple up-down movement of the claws during the reproductive season. Large males dedicated most of their surface activity to waving displays and gained higher mating success. On the other hand, small males infrequently performed waving displays and devoted their time exclusively to foraging. To examine female preference for the size of waving males, two female-release experiments were conducted. In the experiments, we recorded female choice between small- and large-waving claw models over short (10 cm) and long (25 cm) distances. In both the short- and long-distance choice experiments, significantly more females chose the large-claw model over the small-claw model. The following characteristics may produce obvious age-dependent sexual advertisement in I. pusilla, which grows throughout a life: (1) the strong female preference for large claws; (2) the short, 2-year lifespan that includes only two reproductive seasons; and (3) the lack of alternative mating strategies (e.g., surface mating).  相似文献   

12.
Changes in the signaling effort of virgin females are known to occur until their first mating. Young females tend to increase the calling effort (number and time duration of bouts) as they age. In this context, the calling behavior of virgin females of Atheloca subrufella, an important pest of coconut palms (Cocos nucifera), was studied under laboratory conditions. Thirty four virgin females were observed during 16 scotophases (25 ± 2 °C, 75 ± 5 % RH and 10 h scotophase), until they stopped calling in the following photophase. The calling position, pattern and frequency were evaluated. Females of A. subrufella showed only one calling position, and calling peaked between the second and fifth scotophases. Most females did not start calling immediately after emergence. Neither the individual duration of calling nor the number of calling bouts changed over time. However, the time that calling started was earlier in older females, probably to avoid competition with younger females and increase the probability of mating. These data support the hypothesis that there is an age-dependent pattern of pheromone emission in virgin females of A. subrufella.  相似文献   

13.
Reproduction and maturation in the economically important, but data-deficient, Mustelus minicanis and M. norrisi were analysed using catches of populations exploited by a gillnet fishery during two years in the southern Caribbean Sea. In total, 691 female (mean ± SD total length–TL of 55.3 ± 5.8 cm) and 503 male (50.4 ± 4.9 cm TL) M. minicanis were assessed, with ~95% of all specimens deemed mature. Almost 25% of females were gravid (occurring between January and October) and with variable temporal development of up to six embryos (3.3 ± 1.2), implying protracted temporal parturition. Parity in the sex ratio of embryos, but not in landed catches, suggested sexual segregation across the fished area. The 50% sizes at maturity (M 50) (± SE) were similarly estimated at 45.11 (± 0.39) and 45.48 (± 0.42) cm TL for females and males, respectively. Relatively fewer (235) M. norrisi were landed, with samples comprising 150 females (82.6 ± 18.1 cm TL) and 85 males (75.5 ± 17.7 cm TL). More than 30% of both sexes were immature. Ten percent of females were gravid (up to 11 embryos) and present in catches between October and February, coinciding with the northern hemisphere autumn/winter. Female and male M 50s were 76.65 (± 1.16) and 69.63 (± 1.92) cm TL, respectively. The results imply variable inter-specific reproductive plasticity and the need for further life-history studies. Increasing gillnet selectivity might represent a simple precautionary management option for concurrently regulating catches of the smaller-bodied M. minicanis during peak abundances of gravid females and similar-sized juvenile M. norrisi.  相似文献   

14.
When animal home ranges overlap extensively in species lacking overt territorial behaviours, identifying exclusive core areas within individual ranges can be difficult. By analysing the size and overlap of successively smaller core areas among individual Eurasian red squirrels (Sciurus vulgaris), we determined exclusive areas within the home ranges of resident males and females. Possible effects of habitat composition and food supplies were explored by monitoring squirrels in different conifer forests and during years with low and high tree seed production. Using outlier-exclusive cores (OEC) revealed that the total ranges consisted of large sally zones (on average, 35% of the total minimum convex polygon [MCP] range) around home ranges with multi-nucleate cores. The mean OEC home range size did not differ between the sexes but was larger with poor food availability. Home ranges (99% incremental cluster polygons [ICP]) overlapped extensively between sexes (average overlap high food–low food: males by females 21–40%, females by males 43–45%) and among males (males by males 26–44%), while intrasexual overlap among females was low (9–10%). The overlap of inner cores among females rapidly approached zero, suggesting the intrasexual territoriality of 75% core areas. This was not the case among male squirrels, for which intrasexual overlap averaged only 4% at 50% but 18% at 75% core areas. Even the smallest inner cores had some degree of intersexual overlap, indicating that complete territoriality did not occur in this species. Female home ranges were more strongly affected by annual fluctuations in food supplies than male ranges. Females reduced the size of their food-based intrasexual territories when food availability increases. Males probably benefit from using larger home ranges and core areas, which overlap with the ranges of several females, by increasing their probability of successful mating.  相似文献   

15.
The mating system and sexuality of the gobiid fish Trimma marinae were investigated in aquaria and by gonadal histological examination. The male to female sex ratio in the study aggregation was female biased (14:27), and females were larger than males. T. marinae were monogamous because they established continuous pairs and spawned repeatedly with the same individuals. Observations of aggressive behavior suggested that the monogamous mating system resulted from female mate guarding. We also performed a rearing experiment to test whether sex change occurs in this species. None of the males or females reared separately in aquaria for 63 days changed sex. Additionally, gonadal histology revealed that mature fish had unisexual gonads (testis or ovary). These results strongly suggest that T. marinae is gonochoristic. However, immature fish had a bisexual gonadal structure, indicating juvenile hermaphroditism.  相似文献   

16.
The demography and reproductive biology of three Epinephelus groupers (Serranidae), namely E. polyphekadion, E. tauvina, and E. howlandi in the Yaeyama Islands, Okinawa, were examined based on age assessment using otoliths and gonadal histology. The maximum ages for these three species were 26 year, 23 year, and 17 year. The von Bertalanffy growth functions were also determined for each species. The size and age at 50% female maturity were estimated to be 358 mm in total length (TL) and 6.0 year for E. polyphekadion, 371 mm TL and 6.7 year for E. tauvina, and 327 mm TL and 4.1 year for E. howlandi, respectively. Significant differences between the sexes in size and age frequencies were found in all three species, with males being larger and older than females, or transitional individuals. These results strongly indicated that the population of these three grouper species showed monandric protogynous hermaphroditism. The sex ratios of E. polyphekadion and E. tauvina were biased in favor of females, but that of E. howlandi was equivalent between sexes. The relative sizes of ripe testes indicated that the intensity of sperm competition varied among species suggesting different mating system of each species. Reproductive seasonality was similar among species, with active vitellogenesis coinciding with the annual rise in water temperature. The active spawning period was determined to be between April and May for E polyphekadion, in May for E. howlandi, and from March to June for E. tauvina.  相似文献   

17.
Riverbanks in Thailand are home to two fireflies, Pteroptyx malaccae and Pteroptyx valida, which form massive mixed-species mating congregations. In conservation, both represent flagship species that attract much public attention. However, their populations have become sparse. With the increasing spread of urbanization, more information is needed on whether and how the fireflies are able to adapt to such new environments. 24 population surveys were conducted across 13 months at a park surrounded by an urban area in Samut Prakan Province to record their pattern of occurrence. The results showed a year-round presence with high abundance around Jul-Oct, corresponding to local rainy season. On average, the park housed 7?±?3 congregations with a total of 488?±?274 displaying males (Mean?±?SD, Max?=?1281, Min?=?111, N?=?24). Congregation sizes ranged from 5 to 560 males with an average of 70 (N?=?172) and the ratio of P. malaccae to P. valida around 3:1. The distribution pattern was dominated by a few very large and long-lasting congregations that contained most of the males in the area. Location-wise, these large congregations tended to occur at certain “hotspots”, which may aid in flash visibility. Theoretical comparison to hilltopping and other lekking insects was discussed. In terms of plant species, the fireflies most often utilized Sonneratia caseolaris as congregation platform which is consistent with many other areas. However, exotic ornamental plants such as Terminalia catappa were also frequently used here, especially during the rainy season. The behavioral adaptability may aid conservation efforts.  相似文献   

18.
Despite the importance of roe deer as a host for Ixodes ticks in central Europe, estimates of total tick burden on roe deer are not available to date. We aimed at providing (1) estimates of life stage and sex specific (larvae, nymphs, males and females, hereafter referred to as tick life stages) total Ixodes burden and (2) equations which can be used to predict the total life stage burden by counting the life stage on a selected body area. Within a period of 1½ years, we conducted whole body counts of ticks from 80 hunter-killed roe deer originating from a beech dominated forest area in central Germany. Averaged over the entire study period (winter 2007–summer 2009), the mean tick burden per roe deer was 64.5 (SE ± 10.6). Nymphs were the most numerous tick life stage per roe deer (23.9 ± 3.2), followed by females (21.4 ± 3.5), larvae (10.8 ± 4.2) and males (8.4 ± 1.5). The individual tick burden was highly aggregated (k = 0.46); levels of aggregation were highest in larvae (k = 0.08), followed by males (k = 0.40), females (k = 0.49) and nymphs (k = 0.71). To predict total life stage specific burdens based on counts on selected body parts, we provide linear equations. For estimating larvae abundance on the entire roe deer, counts can be restricted to the front legs. Tick counts restricted to the head are sufficient to estimate total nymph burden and counts on the neck are appropriate for estimating adult ticks (females and males). In order to estimate the combined tick burden, tick counts on the head can be used for extrapolation. The presented linear models are highly significant and explain 84.1, 77.3, 90.5, 91.3, and 65.3% (adjusted R 2) of the observed variance, respectively. Thus, these models offer a robust basis for rapid tick abundance assessment. This can be useful for studies aiming at estimating effects of abiotic and biotic factors on tick abundance, modelling tick population dynamics, modelling tick-borne pathogen transmission dynamics or assessing the efficacy of acaricides.  相似文献   

19.
The effects of feeding on root by the larvae and three types of Momordica cochinchinensis Spreng (Cucubitaceae) leaves (young, mature and senescent) by the adults of Aulacophora foveicollis Lucas (Coleoptera: Chrysomelidae) were studied under laboratory conditions. Total larval developmental time was 19.7 ± 0.2 days by feeding on young roots. Adult males lived for 28.4 ± 1, 65.7 ± 1.1 and 22.8 ± 1.3 days on young, mature and senescent leaves, respectively; whilst adult females lived for 34.3 ± 1.2, 68.5 ± 0.9 and 26.4 ± 1.4 days on young, mature and senescent leaves, respectively. Fecundity was highest in mature leaves fed insects (202.2 ± 10.6). Total carbohydrate, protein, lipid, nitrogen and amino acid were much higher in root followed by mature leaves than young and senescent leaves. Moisture content was highest in mature leaves than the roots, young and senescent leaves. Phenols were greatest in young leaves followed by mature leaves and least in senescent leaves and roots of the said plant. Flavonols were higher in young leaves and least in root. These results suggest that A. foveicollis adults perform better on mature leaves than young and senescent leaves for their nutrition.  相似文献   

20.
The factors that affect the home range size of domestic cats (Felis silvestris catus) in a semi-domesticated condition (i.e., cats that receive shelter and food from humans but are free to move in the wider natural environment) is not completely understood. Here, using radio telemetry, we present the first assessment of the home range size and activity patterns of male domestic cats living in the insular environment of Brazil’s Atlantic Forest, and examine the extent to which these were influenced by the presence (‘resident males with females’: RMF group) or absence (‘single males’: SM group) of females in the residences of their owners. Daily and seasonal activity patterns have also been characterized. Home ranges of the RMF were markedly smaller than that of the SM and exhibited less overlap with the home ranges of other males than did those of the SM. Male cats were most active at twilight and evening (44.68 ± 1.07) and least active in the afternoon (28.76 ± 2.79). RMF presented nocturnal activity greater than SM, especially in the dry season. Our data indicate that presence of females is an important factor in shaping these parameters of domestic male cats.  相似文献   

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