Search

Reproductive isolation is one of the mechanisms of speciation. The two currently accepted subspecies of Parodia haselbergii (P. haselbergii subsp. haselbergii and P. haselbergii subsp. graessneri) were studied regarding flower traits, phenology, breeding systems and pollination. In addition, a principal component analysis with 18 floral characters and germination tests under controlled conditions were performed for both taxa. Pollination was studied in the field, in two localities of Southern Brazil. Pollinators were recorded through photos and film. Breeding system experiments were performed by applying controlled pollinations to plants excluded from pollinators. Both taxa mostly differ in asynchronous flowering periods, floral traits (including floral part measurements and nectar concentration) and pollinators. The flowers of both subspecies are functionally protogynous and perform remarkably long lifespans (≥ 15 days), both traits being novelties for Cactaceae. Whereas the reddish flowers of P. haselbergii subsp. haselbergii (nectar concentration: ca. 18%) are pollinated by hummingbirds of Thalurania glaucopis, the greenish flowers of P. haselbergii subsp. graessneri (nectar concentration: ca. 29%) are pollinated by Augochlora bees (Halictidae). Both subspecies are self-compatible, yet pollinator-dependent. The principal component analysis evidenced that both subspecies are separated, regarding flower traits. The seeds of both subspecies performed differently in the germination tests, but the best results were recovered at 20 °C and germination considerably decreased around 30 °C. In conclusion, all these results support that both taxa are in reproductive isolation, and can be treated as different species. [ABSTRACT FROM AUTHOR]

Trapping trichomes, a common trait found in protogynous trap flowers, are thought to enable interaction with pollinators, promoting both pollen removal and fruit set. However, this hypothesis has yet to be empirically confirmed. In this study, we experimentally tested whether trapping trichomes favour male and female functions in trap flowers. Using protogynous South American Aristolochia esperanzae trap flowers, we observed the temporal variation in both sexual functions and associated them with the wilting of the flower and trapping trichomes. Next, we described the trapping trichomes features associated with the capture, entrapment and release of pollinators. Finally, we used manipulative experiments involving trapping trichome removal to quantify their influence on pollinator entrapment, pollen removal and fruit set. While flowers wilted after the end of the female phase, the trapping trichomes only wilted some hours after pollen presentation, promoting a delay in the exit of pollinators, so they carried pollen. Trapping trichomes features, such as a density gradient towards the interior of the tube, unidirectional orientation and epicuticular waxes, may be important in the capture and entrapment of pollinators. Trapping trichome removal decreased drastically the probability of pollinator entrapment and pollen removal, leading to no fruit set. These results indicate that the evolution and maintenance of trapping trichomes in trap flowers probably occurred through selective pressures from both sexual functions and highlight their role in the functioning of this highly phenotypically specialized pollination system. Read the free Plain Language Summary for this article on the Journal blog. [ABSTRACT FROM AUTHOR]

Species within the primitive genus Magnolia may often produce specialized floral traits and behaviour to grab the attention of potential pollinators from their surroundings. These reproductive traits in plants undergo various selection pressures and frequently bring forth variations to adapt to the new habitat that may result in speciation. We have aimed to understand the floral traits, the functional role of floral parts, and the variable response of visitors in Magnolia grandiflora belonging to an ancient order Magnoliales. Our observations reveal that the floral traits of M. grandiflora resemble those of basal angiosperms, conforming to the primitive existence of the genus Magnolia. The inconsistency in floral form reflected that M. grandiflora has been experiencing various selection pressures from biotic and abiotic factors. Inconsistency in floral equations and diagrams reflect the structural variability in flowers, which can directly impact pollination and reproductive output. SEM images of pollen grains reveal that the pollen grains were monocolpate and boat-shaped in structure. GC-MS analysis showed that VOCs in stigmatic exudation of the flower were largely composed of terpene hydrocarbons such as Perthenine, β-Elemene, β-Caryophyllene, α-Humulene, Bicyclogermacrene, Germacrene A and D, etc. Beyond pollinators attraction, VOCs play a major role in repelling unwanted visitors and in improving the defensive mechanisms in Magnolia. Beetles, bees, and flies were found to be the active pollinators and the behaviour of bees indicates that bees were trying to replace the role of beetles in pollinating M. grandiflora. In summary, floral whorls were diversely functionalized to ensure maximum reproduction in M. grandiflora.

Most Aristolochiaceae species studied so far are from temperate regions, bearing self‐compatible protogynous trap flowers. Although self‐incompatibility has been suggested for tropical species, the causes of self‐sterility in this family remain unknown. To fill this gap, we studied the pollination of the tropical Aristolochia esperanzae, including the physical and physiological anti‐selfing mechanisms.Floral visitors trapped inside flowers were collected to determine the pollinators. Protogyny was characterized by observing the temporal expression of sexual phases and stigmatic receptivity tests. The breeding system was investigated using hand‐pollination treatments. Pollen tube growth was observed using epifluorescence to identify the self‐incompatibility mechanism.Flies were the most frequent visitors found inside A. esperanzae trap flowers, with individuals from the family Ulidiidae being potential pollinators since they carried pollen. The characteristic flower odour and presence of larvae indicate that A. esperanzae deceives flies through oviposition‐site mimicry. Although this species showed incomplete protogyny, stigmatic receptivity decreased during the male phase, avoiding self‐pollination. Fruits developed only after cross‐ and open pollination, indicating that the population is non‐autonomous, non‐apomictic, and self‐sterile. This occurred through a delay in the growth of geitonogamous pollen tubes to the ovary and lower ovule penetration, indicating a late‐acting self‐incompatibility mechanism.Our findings expand the number of families in which late‐acting self‐incompatibility has been reported, demonstrating that it is more widespread than previously thought, especially when considering less‐studied tropical species among the basal angiosperms. [ABSTRACT FROM AUTHOR]

For most vertebrates, sexual fate is genetically determined and remains fixed throughout life. However, for some teleost fishes sex is more plastic. Significant progress has been made in characterising the cellular and molecular processes that underpin gonadal sex change. The brain-mediated mechanisms that underlie and initiate this transformation, however, remain poorly understood. One reason for this is the current lack of a neuroanatomical reference work for sex changing fishes. Here, we present a brain atlas for the New Zealand (NZ) spotty wrasse (Notolabrus celidotus), developed from 10 wild caught specimens (2 male and 8 female). From each fish, coronal cryosections were collected and stained with cresyl violet solution. Photomicrographs were taken of each section using an inverted bright field microscope and 3D reconstructions were rendered of each brain for annotation and volumetric comparison of specific brain regions. The brain atlas describes the general features of the NZ spotty wrasse brain as well as its specificities. This atlas provides the necessary foundation for further investigation of the brain mechanisms driving protogyny in this species. [ABSTRACT FROM AUTHOR]

Lemna aequinoctialis Welw. is a widely spread species that has diverse physiological and molecular properties. Flower characteristics are important factors in deducing taxonomical status; however, owing to the rarity of flowering observations in Lemna, studying them has been a prolonged challenge. In this study, physiological and morphological analyses were conducted by inducing flowering, and molecular analysis was done based on the two chloroplast DNA loci (matK, atpF−atpH intergeneric spacer) of L. aequinoctialis sensu Landolt (1986) from 70 strains found in 70 localities in Japan, Korea, Thailand, and the US. In total, 752 flowering fronds from 13 strains were observed based on axenic conditions. Two different trends in flower organ development—protogyny and adichogamy—were detected in these strains. Their physiological traits were divided into two groups, showing different morphological features based on frond thickness, root cap, and anther sizes. Molecular analysis showed two lineages corresponding to two physiological groups. These were identified as L. aequinoctialis sensu Beppu et al. (1985) and L. aoukikusa Beppu et Murata based on the description of the nomenclature of L. aoukikusa. These were concluded as independent taxa and can be treated as different species. Furthermore, the distribution of L. aoukikusa is not only limited to Japan. [ABSTRACT FROM AUTHOR]

The andromonoecy is an unusual sex expression in trees in which an individual plant bears both functionally staminate and hermaphrodite flowers on the inflorescences. This study aims to investigate the effect of crown layers on the floral biology and reproductive effort of Aesculus indica (Wall. ex Camb.) Hook. The results revealed that the peak period of anthesis was between 06:00 and 08:00 h of the day. Male flower production was predominantly higher as compared to the perfect flowers on the inflorescences. There was no significant variation between total pollen production in staminate and perfect flowers. Features like protogyny and inter-level asynchrony promote xenogamy; however, intra-level asynchrony results in geitonogamy. Controlled pollination treatments revealed the existence of self-incompatibility in flowers. Pollination syndromes in flowers support ambophily. A trend of consistent improvement in reproductive success from lower canopy layers to upper crown layers in the analyzed trees was recorded. The crown layers have a significant impact on flower production, fruit, and seed set. An increase in male flower production due to the increment in the crown is a mechanism of reproductive assurance as a pollen donor and pollinator recipient and also due to the differential cost of expenditure of reproduction in crown layers. Andromonoecy in A. indica promotes self-incompatibility, and there was a tapering trend of reproductive success in the crown layers. [ABSTRACT FROM AUTHOR]

Females and males may have distinct phenotypic optima, but share essentially the same complement of genes, potentially leading to trade-offs between attaining high fitness through female versus male reproductive success. Such sexual antagonism may be particularly acute in hermaphrodites, where both reproductive strategies are housed within a single individual. While previous models have focused on simultaneous hermaphroditism, we lack theory for how sexual antagonism may play out under sequential hermaphroditism, which has the additional complexities of age-structure. Here, we develop a formal theory of sexual antagonism in sequential hermaphrodites. First, we construct a general theoretical overview of the problem, then consider different types of sexually antagonistic and life-history trade-offs, under different modes of genetic inheritance (autosomal or cytoplasmic), and different forms of sequential hermaphroditism (protogynous, protoandrous or bidirectional). Finally, we provide a concrete illustration of these general patterns by developing a two-stage two-sex model, which yields conditions for both invasion of sexually antagonistic alleles and maintenance of sexually antagonistic polymorphisms. [ABSTRACT FROM AUTHOR]

We investigated reproductive behavior and sexual patterns in two odacid fish—Rainbow cale Heteroscarus acroptilus and Herring cale Olisthops cyanomelas—inhabiting temperate reefs in Australia on the basis of underwater observations and histological studies. The males of both species established a territory and continuously courted females they encountered in the territory. The males and females went up in the water column to release gametes in pairs. We found ovarian cavities in the gonadal tissue of H. acroptilus males, suggesting that protogynous sex change occurred in this species. Dichromatism is reported in O. cyanomelas, with males having a dark blue body color while females have a brown body color; however, we found small mature males also included among brown individuals. Furthermore, we diagnosed O. cyanomelas with gonochorism, which is rare in closely related labrids. We compared the similarities and differences in reproductive behavior and sexual patterns between the two species and with labrids. [ABSTRACT FROM AUTHOR]

Growth rate, longevity, maturity and spawning seasonality were estimated for the endemic Hawaiian hogfish Bodianus albotaeniatus. The sex‐specific von Bertalanffy growth parameters are L∞ = 339 mm fork length (LF) and K = 0.66 year−1 for females and L∞ = 417 mm LF and K = 0.33 year−1 for males. The maximum age is 22 years. Histological gonad analysis and the absence of small and young males indicate a monandric protogynous hermaphrodite. Size and age at maturity for combined sexes are L50 = 238 mm LF and A50 = 1.6 years. [ABSTRACT FROM AUTHOR]

Many plants express their female and male sex roles at different times (dichogamy), with important consequences for mating. Dichogamy can yield mate limitation via biased floral sex ratios, particularly at the beginning and end of the flowering season when many plants simultaneously function as the same sex. This form of mate limitation should be reduced if plants adjust their allocations to female versus male sex functions in a manner that tracks seasonal variability in mating opportunities. For example, under protogyny (i.e. dichogamy with female function expressed first) plants with male-biased sex expression should have enhanced mating opportunities early in the flowering season as other plants begin to flower (in female sex phase). We quantified seasonal changes in sex allocation, patterns of mate availability and realized siring success in a population of protogynous Sagittaria latifolia. Our results were consistent with previous findings that seasonal changes in sex allocation should compensate for lost mating opportunities under the temporally variable mating environments caused by dichogamy. However, patterns of siring success in the population were inconsistent with this interpretation. We suggest that realized siring success might depend more strongly on spatial than on temporal aspects of mate availability.

The fall armyworm (FAW) Spodoptera frugiperda (J. E. Smith; Lepidoptera; Noctuidae) has invaded Jiangxi Province, Southeast China for the past 3 years. Although the FAW displays a wide host range, its main host plants in Jiangxi Province are field corn. Understanding the population dynamics of the FAW on different host plants is critical for developing an appropriate control strategy. This study investigated the effects of food plants (corn, peanut, soybean and sugarcane) on life‐history traits of FAW and tested the leaf contents of the total flavonoids, reducing sugars, sucrose and C/N ratio of these host plants. We found that the FAW fed on corn leaves exhibited significantly shorter larval and pupal development times, larger body weight, higher growth rate, lower weight loss, smaller sexual size dimorphism, shorter preoviposition period and higher fecundity than those fed on peanut, soybean and sugarcane leaves. The FAW showed a protogyny phenomenon because the pupal development stage was significantly longer in males than females. Food plants changed the relationships between larval development time and pupal weight and between fecundity and longevity. The corn leaves showed significantly higher contents of reducing sugars and sucrose, lower content of the total flavonoids and a moderate C/N ratio compared with the other leaves, suggesting that the corn leaf tissues are more nutritious. Our results provide the most comprehensive information about the life‐history traits of this newly invasive pest. These findings may help us understand why the FAW mainly infests corn plants and may be critical for the development of strategies to predict infestation levels. [ABSTRACT FROM AUTHOR]

The article discusses research on the floral reproductive biology and nectar chemistry of the rare perennial Jalmota grandiflora (Solanaceae) from Mexico. Topics covered include the range of nectar glucose, fructose and sucrose content per flower based on refractometer studies, stigma declines in receptivity during the life of the flower, and the selective force in floral evolution.

Sexual size dimorphism (SSD) is shaped by multiple selective forces that drive the evolution of sex-specific body size, resulting in male or female-biased SSD. Stronger selection on one sex can result in an allometric body size scaling relationship consistent with Rensch's rule or its converse. Anurans (frogs and toads) generally display female-biased SSD, but there is variation across clades and the mechanisms driving the evolution of SSD remain poorly understood. We investigated these topics in a diverse family of African treefrogs (Hyperoliidae). Hyperoliids display traits considered rare among amphibians, including sexual dichromatism and protogynous sex change. Using phylogenetic comparative methods, we tested if adult ecology, sexual dichromatism, and sex change were predictors of body size or SSD. We also tested whether hyperoliids displayed allometric interspecific body size scaling relationships. We found a majority of hyperoliid taxa display female-biased SSD, but that adult ecology and sexual dichromatism are poor predictors of sex-specific body size and SSD. Regardless of the groupings analyzed (partitioned by clades or traits), we found support for isometric body size scaling. However, we found that sex change is a significant predictor of SSD variation. Species in the Hyperolius viridiflavus complex, which putatively display this trait, show a significant reduction in SSD and are frequently sexually monomorphic in size. Although protogynous sex change needs to be validated for several of these species, we tentatively propose this trait is a novel mechanism influencing anuran body size evolution. Beyond this association, additional factors that shape the evolution of anuran body size and SSD remain elusive.

Flowers of Jaltomata weigendiana (Solanaceae) secrete red nectar that is visible through the partially translucent corolla. We report the pattern of nectar presentation during the sexual phases of the flower and characterize the breeding system. Comparison of flower sets experiencing daily removal starting Day 1 with flowers that accumulated nectar for one or two days prior to daily removal revealed no discernible effect on the life-of-the-flower nectar production, sugar production and floral longevity. Flowers produce about the same cumulative volume of nectar during the two sexual phases. However, cumulative nectar sugar production is about 4 times higher during the male phase. Nectar standing crop ranged from 4–26.6 µl for Day 1 flowers and 0–8.7 µl for flowers from which nectar was removed the previous day. With daily removal of nectar, 21 of 40 flowers contained no nectar during the last day of the flower's life. All unmanipulated flowers developed fruits (autonomous self-pollination). However, manual self-pollinations and manual cross-pollinations resulted in fruits that weighed significantly more and had significantly more seeds than fruits produced by autonomous self-pollination. Protogyny and herkogamy promote cross-pollination, but delayed autonomous selfing at the end of the flower's life ensures seed set if pollinator-mediated pollination fails. [ABSTRACT FROM AUTHOR]

Summary statement: Socially induced sex change is orchestrated by a novel combination of genes and epigenetic factors that govern sex differentiation and cell fate. Approximately 500 fish species can change sex in adulthood. The molecular basis for this astonishing transformation remains broadly unknown. Genetic regulation of embryonic sex differentiation is well established in vertebrates but also appears influential in sequential hermaphrodites. Recent work indicates that epigenetic effects and genes regulating cell fate are also important drivers of sex change. Here we use the spotty wrasse to investigate gonadal sex change at a molecular level. While the expression of some sex differentiation genes (dmrt1, foxl2a, ctnnb1) in spotty wrasse follow established sex-biased patterns, others (sox9a, znrf3, rspo1) oppose typical vertebrate-models. We propose that gene neofunctionalisation due to teleost whole-genome duplication may explain these counter-intuitive expression profiles. Significant epigenetic reprogramming within the transitional spotty wrasse gonad is implied through the dynamic expression of methyltransferases and the chromatin-modifying Jumonji family genes, jarid2b and kdm6bb. Furthermore, our results show that fancl and pou5f3, two genes associated with either DNA repair pathways or stem cell pluripotency, are downregulated as sex change advances. This highlights genetic factors that may underlie a functional change of cell fate trajectory. Collectively, this work demonstrates the diversity of genetic pathways that are dynamically activated in a phased, sex-specific manner to co-ordinate vertebrate sex change. [ABSTRACT FROM AUTHOR]

In seasonal environments, competition among males can drive males to emerge before females. Females, simultaneously, should avoid emerging at times after sufficient male availability. We show that the consequent sexual conflict over timing traits can produce arms races toward ever earlier emergence, if low mate-search efficiency or sperm limitation elevate the latter risk for females. In reality, however, arms races over timing cannot proceed indefinitely as this ignores the relevant ecological context for phenology: the temporal niche of resource availability for offspring development. We model the interaction of natural and sexual selection to predict the sexual conflict load, i.e. the loss of population fitness caused by sexual conflict. We show that selection to avoid matelessness can exacerbate another problem of maladaptation: a temporal mismatch between the organism (e.g. insect) and its resource (e.g. host plant). Load frequently associates with protandry if males can mate multiply, yet lack of multiple mating does not imply zero load. A temporal mismatch can still evolve, where both sexes emerge and mate suboptimally early with respect to the seasonal resource peak, because monogamy does not guarantee that every individual finds one mate, and selection favors early individuals in mate-finding contexts. [ABSTRACT FROM AUTHOR]

The andromonoecy is an unusual sex expression in trees in which an individual plant bears both functionally staminate and hermaphrodite flowers on the inflorescences. This study aims to investigate the effect of crown layers on the floral biology and reproductive effort of Aesculus indica (Wall. ex Camb.) Hook. The results revealed that the peak period of anthesis was between 06:00 and 08:00 h of the day. Male flower production was predominantly higher as compared to the perfect flowers on the inflorescences. There was no significant variation between total pollen production in staminate and perfect flowers. Features like protogyny and inter-level asynchrony promote xenogamy; however, intra-level asynchrony results in geitonogamy. Controlled pollination treatments revealed the existence of self-incompatibility in flowers. Pollination syndromes in flowers support ambophily. A trend of consistent improvement in reproductive success from lower canopy layers to upper crown layers in the analyzed trees was recorded. The crown layers have a significant impact on flower production, fruit, and seed set. An increase in male flower production due to the increment in the crown is a mechanism of reproductive assurance as a pollen donor and pollinator recipient and also due to the differential cost of expenditure of reproduction in crown layers. Andromonoecy in A. indica promotes self-incompatibility, and there was a tapering trend of reproductive success in the crown layers.

We investigated reproductive behavior and sexual patterns in two odacid fish—Rainbow cale Heteroscarus acroptilus and Herring cale Olisthops cyanomelas—inhabiting temperate reefs in Australia on the basis of underwater observations and histological studies. The males of both species established a territory and continuously courted females they encountered in the territory. The males and females went up in the water column to release gametes in pairs. We found ovarian cavities in the gonadal tissue of H. acroptilus males, suggesting that protogynous sex change occurred in this species. Dichromatism is reported in O. cyanomelas, with males having a dark blue body color while females have a brown body color; however, we found small mature males also included among brown individuals. Furthermore, we diagnosed O. cyanomelas with gonochorism, which is rare in closely related labrids. We compared the similarities and differences in reproductive behavior and sexual patterns between the two species and with labrids.

Male and female Spicara flexuosa (Rafinesque, 1810) may be considered as two distinct stocks whose population can be monitored and managed separately due to sexual dimorphism. This study focused on revealing the sex inversion, sexual dimorphism, and morphological differences of S. flexuosa in the Black Sea based on traditional morphometric characters. The sex inversion length was estimated as 140 mm according to binomial analysis. Male specimens exhibit positive allometric growth, indicating that males invest more in body weight than in length. Our results indicated male individuals being characterized by deeper bodies and longer fins than females. Results from this study show four morphological differences between male and female S. flexuosa indicating pronounced sexual dimorphism. [ABSTRACT FROM AUTHOR]

Protogynous sex change has been widely reported as a life-history strategy in polygynous reef fish. Dascyllus reticulatus is known to form haremic colonial groups on branching corals and is thought to undergo protogynous sex change based on gonad histology. We conducted a 2-year underwater survey on 13 haremic groups to examine the sex-change patterns of D. reticulatus on reefs of southern Japan. We observed 11 instances of protogynous sex change. One involved a take-over sex change by the largest female following the disappearance of the dominant male. In other contexts, females undergo sex changes in the presence of males or larger females. These sex-change individuals commonly had limited mating opportunities as females. Of the ten sex changers, five subordinate females became bachelor males showing no sexual behavior despite their ability to release sperm. Owing to behavioral crypticity, these bachelor males remained within their groups without suffering attacks from territorial males. Furthermore, sex changers showed higher growth rates than females. Two bachelor sex changers subsequently obtained mating status, of which one became a female again after inter-group migration. It is suggested that female D. reticulatus often overcomes reproductively isolated situations via the growth advantages of protogynous sex change and sexual plasticity. [ABSTRACT FROM AUTHOR]

Abstract In mid‐May, 2019, the fall armyworm (FAW) Spodoptera frugiperda invaded Jiangxi Province, China, and caused extensive damage to corn crops. However, little attention has been given to the life‐history traits of the FAW. In the present study, we systematically investigated the life‐history traits of the newly invasive FAW on corn leaves at 19, 22, 25, 28, and 31°C under a photoperiod of LD 15:9 hr. The FAW thrived on the corn leaves with short developmental periods, high survival rates of larvae and pupae, very high mating success rates, and high fecundity. The pupal developmental stage was significantly longer in males than females at all temperatures, thus resulting in a protogyny phenomenon. The pupal weight was heaviest after a relatively shorter larval development stage at a higher temperature (25°C); thus, the FAW did not follow the temperature–size rule. Females were smaller than males, indicating sexual size dimorphism. A small proportion of females delayed their pre‐oviposition period and began to lay eggs on the 7th to 9th day after adult emergence. There were positive relationships between pupal weight and larval developmental time and between adult weight and fecundity. There was a negative relationship between fecundity and longevity. These findings can help us to predict the population dynamics of the FAW on corn and to develop a suitable and practical management strategy.

The labrid fish Pteragogus aurigarius undergoes protogynous (female-to-male) sex change, with dichromatic and dimorphic differences in sexes. Similar to some other protogynous fishes, this species is polygynous. We report the size and age at which sex change occurs by monthly sampling fishes at Tateyama, central Japan, from 2011 to 2012, and investigate conditions of sex change in rearing experiments from 2013 to 2015. Sexual phases are determined using gonad histology, and ages by otolith analysis. Of 231 sampled specimens, 99 were female, 129 were male, and three were intersexual. Of males, 86 resembled typical males, and are referred to as "normal males (NM)", and 43 resembled females in color, which we refer to as "males with female appearance (MFA)". NM sizes exceeded those of female, intersexual and MFA individuals. Because intersexual and MFA individuals did not differ in color or size, they may have recently transitioned to being male. Intersexual and MFA individuals ranged 85–135 mm in total length and 1–3 years in age, and appeared from September to March. Because the spawning season runs from June to September, sex change must occur afterwards. Sex change occurred in solitary females, and larger females held with other females in aquaria, both with and without aquarium partitions. Size hierarchy in social groups may be important for sex change of the largest female to male regardless of the number of individuals present. [ABSTRACT FROM AUTHOR]

Hypericum fasciculatum and Stillingia aquatica are abundant codominant shrubs in South Florida depression ponds. Hypericum fasciculatum was studied from multiple perspectives: its competitive context, its adaptations to depression marsh seasonal extremes, and its reproductive biology. Hypericum fasciculatum showed slight intraspecific competition among mature individuals. Its seedling densities diminished with water depths. Interspecific competition with S. aquatica was not detected, probably due in part to markedly divergent root systems. Hypericum fasciculatum is more tolerant of competition from neighboring graminoids than is S. aquatica. The former has wide-spreading sinuous shallow main roots topped with short branch roots rising vertically into the overlying wet substrate. The leaves are dimorphic, with the mature foliage needlelike, having the stomates in abaxial slits. The inner bark is spongy, water-retentive, and substantially thicker than that of other measured local shrubs. Flowering is year-round with usually high fecundity, although flowers abort during drought stress. Seeds per fruit diminished in the wet vs. dry season and with insect-exclusion vs. open pollination. Flowering is protogynous, the buds opening before dawn with the stamens clumped at the base of the style. As the day progresses, the stamens become erect serially with the stigmatic pollen load increasing correspondingly, including with pollinators excluded. Evidence supports extensive self-pollination mixed with entomophily. Insect visitors are diverse. [ABSTRACT FROM AUTHOR]

Age compositions from eight blue cod (Parapercis colias) subpopulations off the South Island of New Zealand were compared to investigate recruitment patterns temporally and spatially. Findings indicate (1) recruitment is highly variable between years, (2) subpopulations closer to each other have similar age compositions, and (3) strong and weak recruitment events are linked and the key processes that drive recruitment strength are acting on a large spatial scale. Recruitment variability among years and similarities between areas are likely to be density-independent, due to environmental fluctuations. Age compositions exhibited modal progression of age classes providing validation of ageing based on counts of rings on otoliths. Sex ratio by age and length were compared in relation to their reproductive strategy of changing sex from female to male (protogynous hermaphrodites). Sex ratio pattern differed for each of the eight subpopulations but was most similar in those from the same area. Males dominate at younger ages and sex ratio swings in favour of females with increasing age. Patterns in sex ratio with size are virtually the opposite to those of age because the largest fish are invariably males. These results support the theory that the form of protogyny in blue cod is diandric. [ABSTRACT FROM AUTHOR]

In mid‐May, 2019, the fall armyworm (FAW) Spodoptera frugiperda invaded Jiangxi Province, China, and caused extensive damage to corn crops. However, little attention has been given to the life‐history traits of the FAW. In the present study, we systematically investigated the life‐history traits of the newly invasive FAW on corn leaves at 19, 22, 25, 28, and 31°C under a photoperiod of LD 15:9 hr. The FAW thrived on the corn leaves with short developmental periods, high survival rates of larvae and pupae, very high mating success rates, and high fecundity. The pupal developmental stage was significantly longer in males than females at all temperatures, thus resulting in a protogyny phenomenon. The pupal weight was heaviest after a relatively shorter larval development stage at a higher temperature (25°C); thus, the FAW did not follow the temperature–size rule. Females were smaller than males, indicating sexual size dimorphism. A small proportion of females delayed their pre‐oviposition period and began to lay eggs on the 7th to 9th day after adult emergence. There were positive relationships between pupal weight and larval developmental time and between adult weight and fecundity. There was a negative relationship between fecundity and longevity. These findings can help us to predict the population dynamics of the FAW on corn and to develop a suitable and practical management strategy. [ABSTRACT FROM AUTHOR]

Juglans mandshurica is a monoecious heterodichogamous species with protogynous and protandrous mating strategies that occur at a 1:1 ratio and are randomly distributed in the population. The inconsistent male and female flowering periods of the same mating type result in an imbalance of the ratio of male and female flowers, contributing to the low yield of this species. However, little more is known about its floral development. Following three consecutive years of observations, histological analysis, and scanning electron microscopy, we found that the morphological and anatomical development of the male and female flowers were synchronous. The male floral morphological development of J. mandshurica was divided into seven phases, while that of the female flower was nine. Four stages were shared between the male and female flower’s anatomical development. Our findings indicate that there was minimal overlap between sexual functions within the same mating type, guaranteeing synchronization, mutual non-interference, outcrossing, and avoidance of self-fertilization. These results provide a theoretical basis for the improvement of fruit yield and quality through the reasonable allocation of protogynous and protandrous individuals in a population, and for artificial pollination control. Further, these findings lay a foundation for further research on the genetic mechanisms and environmental effects on flower development of heterodichogamous J. mandshurica.

Juglans mandshurica is a monoecious heterodichogamous species with protogynous and protandrous mating strategies that occur at a 1:1 ratio and are randomly distributed in the population. The inconsistent male and female flowering periods of the same mating type result in an imbalance of the ratio of male and female flowers, contributing to the low yield of this species. However, little more is known about its floral development. Following three consecutive years of observations, histological analysis, and scanning electron microscopy, we found that the morphological and anatomical development of the male and female flowers were synchronous. The male floral morphological development of J. mandshurica was divided into seven phases, while that of the female flower was nine. Four stages were shared between the male and female flower's anatomical development. Our findings indicate that there was minimal overlap between sexual functions within the same mating type, guaranteeing synchronization, mutual non-interference, outcrossing, and avoidance of self-fertilization. These results provide a theoretical basis for the improvement of fruit yield and quality through the reasonable allocation of protogynous and protandrous individuals in a population, and for artificial pollination control. Further, these findings lay a foundation for further research on the genetic mechanisms and environmental effects on flower development of heterodichogamous J. mandshurica. [ABSTRACT FROM AUTHOR]

• Kersting's groundnut flowers are bisexual and incompletely protogynous. • The flowers are of 'pre-anthesis cleistogamous' type. • Spontaneous self-pollination occurs in the flower, facilitated by style bending. • Emasculation may be done on one-day buds to prevent unwanted self-pollination. Knowledge gap on the reproductive biology of orphan crops is a major challenge to their cultivar development and genetic improvement. This study described the reproductive organs and phenology, assessed receptivity of stigma versus anther dehiscence, and examined pollen viability and germination in Kersting's groundnut. Experiments were conducted on nine morphotypes in a randomized complete block design with three replications in a screenhouse. Phenological observations were made on 1026 flower buds. Anther dehiscence was determined through microscopic observations while receptivity of the stigma was assessed using the hydrogen peroxide test. Pollen viability was assayed using histochemical staining. In vitro germination and pollen tube growth were assessed for up to 72h. Flowers were bisexual and incompletely protogynous, and spontaneous self-pollination was favoured by style bending. Flowering and fruiting were classified into six developmental stages each. Timing of all stages differed significantly (P<0.001) among morphotypes. The stigma was receptive 1-2 days before anther dehiscence and remained so until each flower wilted. Anthesis started 3 days from young bud appearance and lasted between 2–4 days depending on the morphotype. Pollen viability rates were very high (88–98%) and differed among morphotypes (P< 0.001). Pollen germination rates were low (8–37%) and varied among morphotypes and anthesis stages (P <0.05). Pollen tube growth varied significantly among morphotypes, anthesis stages and incubation time. The morphotype ZHLA-2 exhibited the highest reproductive vigour and could be recommended as pollen donor for hybridization. The study provides information on the best time and stage for emasculation and is expected to help breeders optimise a hybridisation protocol. [ABSTRACT FROM AUTHOR]

The pollination syndrome hypothesis usually does not successfully apply to the diversity of floral phenotypes or help predict the pollinators of most plant species. In Bromeliaceae, there is a wide range of floral visitors, making its species ideal to test for a correlation between nectar and floral traits with pollination syndrome. In this study, we analyzed the floral features, nectar production patterns, pollinators and floral visitors of Vriesea gigantea, and discussed its potential adaptive and ecological significance. We study three natural populations from the Atlantic Forest, Southern Brazil. The species presented protogyny and herkogamy, and its anthesis occurred at different periods among different populations. Vriesea gigantea has a relatively constant rate of nectar production during the day that continues overnight but at a reduced rate. Newly opened flowers already have around 80.0 μl of nectar. Although classified as chiropterophilous, based on flower morphology and pollinator observations, our results show that hummingbirds are effective pollinators in the studied populations of V. gigantea. [ABSTRACT FROM AUTHOR]

The importance of interspecific competition in structuring communities of plant-eating insects has been somewhat controversial. If interspecific competition is ever important for phytophagous insects, it is likely to be observed in the insect guild that feeds in the phloem of trees. We tested for signals of interspecific competition in co-occurring species of pine sawyer beetles Monochamus Megerle (Coleoptera Cerambycidae), generally the largest phloemophagous insects in pines. We evaluated patterns of body size and its correlation with other life-history traits. By studying pine sawyer beetles in different areas (Northeast USA, Southeast USA and Portugal) we assessed the interaction with climate. As predicted under the hypothesis of interspecific competition, there were always clear size differences among coexisting species. As predicted if competition is asymmetric, smaller species were less abundant and emerged earlier than the larger species. In the larger and numerically dominant species, sexual size dimorphism was more pronounced and the sex ratio was skewed towards females. In the smaller species, males emerged earlier (protandry), whereas the larger species lacked differences in emergence time or displayed protogyny. Effects of climate only seem to have been expressed in the larger dominant species of each area, whereas the effects of competition in smaller species probably overshadow the effects of climate. [ABSTRACT FROM AUTHOR]

Abstract The pollination syndrome hypothesis usually does not successfully apply to the diversity of floral phenotypes or help predict the pollinators of most plant species. In Bromeliaceae, there is a wide range of floral visitors, making its species ideal to test for a correlation between nectar and floral traits with pollination syndrome. In this study, we analyzed the floral features, nectar production patterns, pollinators and floral visitors of Vriesea gigantea, and discussed its potential adaptive and ecological significance. We study three natural populations from the Atlantic Forest, Southern Brazil. The species presented protogyny and herkogamy, and its anthesis occurred at different periods among different populations. Vriesea gigantea has a relatively constant rate of nectar production during the day that continues overnight but at a reduced rate. Newly opened flowers already have around 80.0 μl of nectar. Although classified as chiropterophilous, based on flower morphology and pollinator observations, our results show that hummingbirds are effective pollinators in the studied populations of V. gigantea.

Fewer than 1% of vertebrate species are hermaphroditic, and essentially all of these are fishes. Four types of hermaphroditism are known in fishes: simultaneous (or synchronous) hermaphroditism (SH), protandry (male-to-female sex change; PA), protogyny (female-to-male sex change; PG), and bidirectional sex change (BS or reversed sex change in protogynous species). Here we present an annotated list of hermaphroditic fish species from a comprehensive review and careful re-examination of all primary literature. We confirmed functional hermaphroditism in more than 450 species in 41 families of 17 teleost orders. PG is the most abundant type (305 species of 20 families), and the others are much less abundant, BS in 66 species of seven families, SH in 55 species of 13 families, and PA in 54 species of 14 families. The recently proposed phylogenetic tree indicated that SH and PA have evolved several times in not-closely related lineages of Teleostei but that PG (and BS) has evolved only in four lineages of Percomorpha. Examination of the relation between hermaphroditism type and mating system in each species mostly supported the size-advantage model that predicts the evolution of sequential hermaphroditism. Finally, intraspecific variations in sexual pattern are discussed in relation to population density, which may cause variation in mating system. [ABSTRACT FROM AUTHOR]

The synchronized dispersal of colonies is an important strategy among social insects in terms of both successful mating and the avoidance of inbreeding. Although several studies have focused on these processes in the most common termite species characterized by pulsed dispersal, only a few studies have reported on termite species characterized by continuous dispersal. Here, we describe the phenology and biological characters of the dispersal flight of Neotermes sugioi, a dry-wood termite native to the Ryukyus Islands of Japan, using five colonies isolated under semi-field conditions over a period of 183 days. We obtained evidence for the synchronicity of alate emergence among colonies of N. sugioi based on observations of synchronous patterns on the major flight and non-flight days, which showed positive correlations in alate emergence between all colony pairs. However, due to the occurrence of months with small correlation coefficients, and inconsistent alate emergence peaks among colonies on a single day, N. sugioi showed less synchronization than subterranean termites characterized by pulsed dispersal flights. Environmental conditions of temperatures and humidities greater than 22 °C and 70% were found to be necessary for high flight activity during both high and low flight seasons. In all colonies, the sex ratio of emerging alates during the observation period was significantly biased toward males. Given that adjustment of synchronous and asynchronous alate release among neighboring colonies could reduce the risk of sibling pair mating and inbreeding, the characteristic alate emergence in N. sugioi may indirectly minimize the potential for inbreeding. [ABSTRACT FROM AUTHOR]

The location of nectar secretion in flowers of Jaltomata has not been identified with certainty until now: removal of the corolla and androecium from one side of living flowers allowed us to see, in progress, nectar secretion by the ovarian nectary. We studied Jaltomata quipuscoae, a wild plant that grows in southern Peru and produces copious, red floral nectar. Unmanipulated flowers do not set fruit in a pollinator-free greenhouse, demonstrating lack of autogamy, but self-compatibility was demonstrated by manual self-pollinations leading to fruit-set. Anther dehiscence is staggered with the anthers of a flower dehiscing over hours on the same day. The corolla and nectar are UV-absorptive. Flowers last 4–10 days, are usually protogynous during the first day the corolla is open, and do not close for the night. [ABSTRACT FROM AUTHOR]

The Frenchman seabream Polysteganus baissaci is an important commercial fish species found on the slopes of the fishing banks of the exclusive economic zone of Mauritius. Exploitation of this species started in 2007, and it is targeted using hydraulic reels with baited hooks. The introduction of suitable management measures is important for this fishery and a sound understanding of the biology is required. Monthly biological data were collected over a 2-year period from fish landed in the commercial catch, to investigate aspects of the biology. A total of 698 females and 1 129 males (sex ratio 1:1.6) were collected from commercial fishing vessels operating on the Nazareth Bank. Females dominated smaller size classes (30–36 cm total length [TL]), whereas males were mostly present at larger sizes (37–44 cm TL). Although ripe and spent female gonads were found throughout the study period, the gonadosomatic index (GSI) revealed a peak in spawning between April and September, coinciding with the cooler sea temperatures in the region. Male GSI (0.169 [SD 0.0443]) during its peak month (August) was more than 14-times lower than the female GSI (2.470 [SD 1.0185]) during its peak month (July), and this, together with male and female length frequencies and adult sex ratios, provides strong supporting evidence for protogyny in this species. Although this fishery appears to harvest adults exclusively, which is positive in terms of sustainability, the potential hermaphroditism in this species necessitates implementation of a conservative harvest strategy, including effort limitation and a closed fishing season over the peak spawning period. [ABSTRACT FROM AUTHOR]

In the common sandpiper both sexes do not participate equally in brood rearing. The attendance of females progressively declines and by the third week after hatching, most of them leave their broods. To check if this unequal parental care results in different migration phenology of males and females, adult common sandpipers were caught at four ringing sites in Poland during their autumn migration and were sexed using a discriminant equation. The median date of female migration was 6 days earlier than that of males. In the first days of July, males comprised only 22% of common sandpipers caught, while later their percent share increased gradually and in August reached up to 80% of captured birds. However, birds of both sexes were present among migrants during the whole migration period and migration period of both sexes overlapped to a great extent. Most probably birds migrating through the study area came from a vast breeding area, where the period of egg laying differs between its northernmost and southernmost parts by at least 1 month.

The Serranidae are well known for protogynous sex change. The red-belted anthias Pseudanthias rubrizonatus inhabits Kagoshima Bay. We aimed to estimate the body size and age of P. rubrizonatus exhibiting sex change. We determined their sex based on the body color and the observation of their gonad. The sampled fish were 0–7 years old, although no individuals 1 or 6 years old were found. The fork length (FL) ranged from 10 to 114 mm. According to estimates from growth curves calculated from the body size of fish of each sex, the theoretical size of individuals exhibiting sex change was 96.9 mm FL and 14.1 g body weight. Gonadal transitions were observed in fish of 81–100 mm FL, 7–14 g body weight, and 2–3 years old, regardless of their apparent sex. These gonads included atretic oocytes in the testis. Most males had ovarian cavities in the testis. Histological observation showed that P. rubrizonatus is a protogynous fish species. [ABSTRACT FROM AUTHOR]

In many taxa, the most common form of sex-biased migration timing is protandry--the earlier arrival of males at breeding areas. Here we test this concept across the annual cycle of long-distance migratory birds. Using more than 350 migration tracks of small-bodied trans-Saharan migrants, we quantify differences in male and female migration schedules and test for proximate determinants of sex-specific timing. In autumn, males started migration about 2 days earlier, but this difference did not carry over to arrival at the non-breeding sites. In spring, males on average departed from the African non-breeding sites about 3 days earlier and reached breeding sites ca 4 days ahead of females. A cross-species comparison revealed large variation in the level of protandry and protogyny across the annual cycle. While we found tight links between individual timing of departure and arrival within each migration season, only for males the timing of spring migration was linked to the timing of previous autumn migration. In conclusion, our results demonstrate that protandry is not exclusively a reproductive strategy but rather occurs year-round and the two main proximate determinants for the magnitude of sex-biased arrival times in autumn and spring are sex-specific differences in departure timing and migration duration. [ABSTRACT FROM AUTHOR]

The reproductive and acoustic behaviours of Gulf grouper Mycteroperca jordani were studied at a spawning aggregation site in the southern Gulf of California, México. In May 2015–2017, divers located and surveyed a spawning aggregation site within Cabo Pulmo National Park. Adult M. jordani conformed to a lek mating system in which large males formed territories over sand adjacent to a rocky reef that were spatially segregated from smaller females outside of courtship and spawning periods. Females moved into male territories during evening hours to spawn. Male courtship behaviours targeted a single female, included head shakes and burst rises and preceded pair spawning prior to sunset. Males and females displayed three shared colour phases, but four phases were sex‐specific. During evening hours, courtship and spawning, both sexes exhibited sexual dichromatism concurrent with reproductive behaviours. The pair‐spawning mating system and observations of bimodal size distributions by sex support previous claims of protogyny in the species. Males produced sounds during territorial patrols, courtship and spawning rushes, which corroborated the importance of acoustic communication within the behavioural repertoire associated with spawning. Long‐term acoustic monitoring revealed increases in total sounds detected day−1 from March through June with diel increases (e.g., evenings) that may be indicative of the spawning season. Observations of spawning on 12 consecutive evenings in May 2017 coupled with extended periods of sound production suggest that spawning does not follow a lunar rhythm. This first description of the mating system and sounds of the endangered M. jordani facilitates future development of seasonal and areal protections to restore and manage the species. [ABSTRACT FROM AUTHOR]

The data of literary sources concerning the bloom of angiosperm plants and deviation in the development of a flower and inflorescence, in particular untimely flowering, was generalized; our observation results of some peculiarities of re-bloom of woody plants in the National Dendrological Park “Sofiyivka” of NAS of Ukraine (NDP “Sofiyivka”) were discussed. The flowering process was formed during a long-term evolution of a propagation system of angiosperm plants as a basis of fertilization and further fruit and seed development. As a result of vernalization and photoperiodism reactions, flowering (under regular conditions) occurs in the most favorable period for pollination and fertilization of every plant. However, various deviations, in particular, the untimely (most frequently double, sometimes three- and four-fold) flowering occurs in this perfect process of generative organ formation of angiosperm plants. An increased number of reports about re-bloom (at the end of summer – at the beginning of fall) of the representatives of various woody plant species whose flowers usually blossom in May-June prompts the analysis of the available information concerning the mechanisms of flowering and the causes which lead to deviation of flowering processes. Flowering of the woody plant representatives of the collection fund of the NDP “Sofiyivka” was studied; statistics about re-bloom in different cities of Ukraine were monitored. The classification of re-bloom facts was carried out according to V.L. Vitkovskiy (1984). Although this classification has mostly a stated nature, it was good enough when being formulated and, with certain conditions, it can be applied nowadays. Accordingly, using this classification, abnormal cases can include facts of early summer-fall flowering and early winter flowering. A late spring flowering can be adaptive response of damaged plants to exogenous stresses, due to which the probability of sexual propagation remains. Early spring-early summer flowering is a dual-natured category which, under certain conditions, may have adaptive meaning and facilitate seminal propagation. Most cases of untimely flowering registered in NDP “Sofiyivka” represent a group of early summer-fall flowering, in some cases late spring flowering occurred though. Secondary flowering is usually connected with meteorological peculiarities of the year. Most frequently it is seen in very dry years, first of all, after hot and dry spring. The rebloom can have an adaptive nature in case of development seeds with full germination, moreover the immature germs of underdeveloped seeds formed from the flowers of early summer-fall flowering can be used in breeding programs.

Many plants express their female and male sex roles at different times (dichogamy), with important consequences for mating. Dichogamy can yield mate limitation via biased floral sex ratios, particularly at the beginning and end of the flowering season when many plants simultaneously function as the same sex. This form of mate limitation should be reduced if plants adjust their allocations to female versus male sex functions in a manner that tracks seasonal variability in mating opportunities. For example, under protogyny (i.e. dichogamy with female function expressed first) plants with male-biased sex expression should have enhanced mating opportunities early in the flowering season as other plants begin to flower (in female sex phase). We quantified seasonal changes in sex allocation, patterns of mate availability and realized siring success in a population of protogynous Sagittaria latifolia . Our results were consistent with previous findings that seasonal changes in sex allocation should compensate for lost mating opportunities under the temporally variable mating environments caused by dichogamy. However, patterns of siring success in the population were inconsistent with this interpretation. We suggest that realized siring success might depend more strongly on spatial than on temporal aspects of mate availability., Competing Interests: We declare no competing interests., (© 2023 The Authors.)

PREMISE OF THE STUDY: The pawpaw, Asimina triloba, is an underutilized fruit crop native to North America that belongs to the mainly tropical, early-divergent family Annonaceae. Asimina is the only genus within the Annonaceae with species adapted to cold climates. A thorough analysis of its reproductive biology, specifically pollen-pistil interaction during the progamic phase, is essential to understand both its adaptation to cold climates and how to optimize its fertilization and fruit set. METHODS: We characterized pollen-pistil interaction in Asimina triloba, including the floral cycle and anatomy, stigmatic receptivity, and the pollen tube pathway. We used a combination of histological, cytological, and immunolocalization approaches. KEY RESULTS: Asimina triloba has a gynoecium formed by plicate carpels with a short stylar canal. Unicellular papillae form a continuous tissue covered by a copious secretion from the stigma to the ovary, which is most prominent on the stigma surface where it forms an extragynoecial compitum. Compared to the stigmas of other species in the Annonaceae, the stigmas of A. triloba show a long stigmatic receptivity associated with a long flowering cycle. Stigmatic receptivity is concomitant with the secretion of cell-wall-related arabinogalactan proteins (AGPs). CONCLUSIONS: A long female phase with a long period of stigmatic receptivity is unusual among protogynous flowers of the magnoliid clade, suggesting a derived condition of A. triloba within the Annonaceae. This phase further correlates with the presence of cell-wall-related arabinogalactan proteins in the secretion, which may indicate the conservation of these glycoproteins during stigmatic receptivity and pollen tube growth in angiosperms. [ABSTRACT FROM AUTHOR]

The Asian sheephead wrasse, Semicossyphus reticulatus, is the largest labrid in temperate waters around Japan. However, the growth pattern of this wrasse remains unclear. Age, growth, and reproduction of S. reticulatus specimens were investigated by sampling in the western Seto Inland Sea, Japan. Opaque ring marks formed on the marginal zone of sectioned otoliths during February-March, suggesting their validity for age estimates. The largest individual was a male, with a standard length (SL) of 591 mm, weight of 8.5 kg, and age of 17 years. Males had significantly larger SLs and older ages than females, and male gonads were histologically confirmed to have secondary testis structures retaining central lumens, suggesting monandric protogyny. The oldest S. reticulatus individual captured was estimated to be a 31-year-old male. The von Bertalanffy growth equation calculated from estimated age and SL was L = 489 (1 − e), indicating considerably slow growth, particularly after the age of 10 years, which is similar to that of the California sheephead wrasse, Semicossyphus pulcher. The humpheads of S. reticulatus enlarged gradually as their body grew, often resulting in a conspicuous humphead, even in large females. [ABSTRACT FROM AUTHOR]