Female crabs enter a stage of rapid ovarian development after mating, and cholesterol is a substrate for steroid hormone synthesis. Therefore, in this experiment, an 8-week feeding trial was conducted to investigate the effects of mating treatments (mated crab and unmated crab) and three dietary cholesterol levels (0·09 %, 0·79 % and 1·40 %) on ovarian development, cholesterol metabolism and steroid hormones metabolism of adult female swimming crab (Portunus trituberculatus). The results indicated that crabs fed the diet with 0·79 % cholesterol significantly increased gonadosomatic index (GSI) and vitellogenin (VTG) content than other treatments in the same mating status. Moreover, mated crabs had markedly increased GSI and VTG content in the ovary and hepatopancreas than unmated crabs. The histological observation found that exogenous vitellogenic oocytes appeared in the mated crabs, while previtellogenic oocytes and endogenous vitellogenic oocytes were the primary oocytes in unmated crabs. The transmission electron microscopy analysis showed that when fed diet with 0·79 % cholesterol, the unmated crabs contained more rough endoplasmic reticulum and mated crabs had higher yolk content than other treatments. Furthermore, mating treatment and dietary 0·79 % cholesterol level both promoted cholesterol deposition by up-regulation of the mRNA and protein expression levels of class B scavenger receptors 1 (Srb1), while stimulating the secretion of steroid hormones by up-regulation of the mRNA and protein expression of steroidogenic acute regulatory protein (Star). Overall, the present results indicated that mating behaviour plays a leading role in promoting ovarian development, and dietary 0·79 % cholesterol level can further promote ovarian development after mating.

Smoking has dangerous and sometimes irreversible effects on various body tissues, including the reproductive system. We conducted this research to determine the in vivo effects of cigarette smoke condensate (CSC) on reproduction in mice. In this experimental in vivo study, 32 male and female NMRI mice were divided into four groups. The mice were injected with CSC (CSC-1R3F) for 28 days. The mice were mated 1 day after the last injection and observed daily for 1 week for the presence of a vaginal plug to track mating. We evaluated mating success rate, and sperm and oocyte quality, pregnancy outcome, childbearing status, and in vitro fertilization (IVF). The results showed a decrease in successful mating in female mice that received the CSC injections. CSC significantly influenced the number of offspring born to males. When the CSC was injected into male mice, there was a significant increase in the number of offspring compared with the group in which only the females received CSC injections. According to the results, there was a negative effect of CSC on morphological parameters in male and female mice. Also, successful IVF after exposure to CSC was significantly decreased in the female mice treated group. The results indicated that CSC significantly affected the number of offspring and fecundity success in females.

Empirical data on the relations between mating and reproductive success are rare for humans, especially for industrial and post-industrial populations. Existing data show that mating (and especially long-term mating) can be beneficial for fitness, especially that of males. This finding is in line with the hypothesis of sexual selection operating in human populations. The present research expands on previous studies by: 1) analysing additional fitness indicators, including having children with different partners; 2) including parental investment in the analysis as another important marker of sexual selection; 3) analysing several mediators between mating, reproductive fitness and parental investment, i.e. age of first and last reproduction and desired number of children. The data were obtained in 2019 from a sample of parents living in Serbia (N=497). The findings showed that long-term mating (duration of longest partner relationship) was positively related to parental investment and number of offspring and grand-offspring. Furthermore, the link between long-term mating and reproductive success was completely mediated by the age of first reproduction and desired number of children. Short-term mating (number of sexual partners) was marginally positively related to the number of children participants had with different partners and negatively related to parental investment. No sex differences in the link between mating, fitness and parental investment were detected. In general, the signatures of sexual selection were weak in the present data, but those that were detected were in line with sexual selection theory. The present findings provide a deeper insight into the adaptive function of mating and also the mechanism of how mating is beneficial for fitness.

Well-being (vs. ill-being) might function as an internal guide for approaching (vs. avoiding) situations, strategies, and achievements that ancestrally led to higher (vs. lower) reproductive success. Indeed, coupled individuals report higher well-being than singles, while depressive individuals report lower mate value and higher sociosexuality. Here we investigate associations between well-being, depression and evolutionary reproduction-related aspects (mate value, intrasexual competition, age, and sociosexuality). Overall, 1,173 predominantly heterosexual Brazilian women (mean = 31.89; standard deviation = 11.10) responded to online instruments measuring self-perceived happiness, life-satisfaction, depression, mate value, intrasexual competition, age, and sociosexuality. Multiple regression models indicated that higher well-being was positively predicted by mate value and negatively by intrasexual competition and sociosexual desire, while the opposite was true for depression. Although intrasexual competition and unrestricted sociosexuality can, under some circumstances, increase individual reproductive success, they are risky and suboptimally effective strategies, thus leading to feelings of ill-being. Contrarily, affective long-term bonds, higher mate-value, and lower intrasexual competition might increase feelings of well-being, because this would lead to a safer route towards ancestral reproductive advantages.

The historical and contemporary presence of southern right whales (SRWs; Eubalaena australis) around the Falkland Islands (Malvinas) has received little recognition. We assessed SRW occurrence in the Falklands via whaling records, a literature review, systematic surveys (boat, aerial and shore-based), and citizen science sightings. The combined data sources indicated a year-round (peaking in austral summer) presence of SRWs in pelagic areas around the Falklands. In contrast, most nearshore records originated in the austral late autumn and winter (May to August), including a marked increase in sightings along the north-east coast during 2017 compared with previous years. The data support spatio-temporal variation in the use of Falklands waters by SRWs. Pelagic waters appear to comprise summer foraging habitat, and may also be used by animals migrating between the Patagonian shelf and feeding grounds located further south and east. The peak numbers observed in nearshore waters occurred earlier in the winter (July) than those on the Argentinean or Brazilian calving grounds (Aug–Oct). Consequently, some whales may have continued migrating northwards to established breeding areas after departing Falklands waters. A component of the south-west Atlantic population could also be using the islands as a novel wintering destination, for mating and/or socializing (no calving has been confirmed to date). The importance of Falklands waters as a multi-use SRW habitat appears to be increasing. The region is important in the context of addressing current knowledge gaps regarding feeding grounds and migratory corridors highlighted in international SRW conservation and management plans for the wider South-west Atlantic.

During human evolutionary history, there were “trade-offs” between expending time and energy on child-rearing and mating, so both men and women evolved conditional mating strategies guided by cues signaling the circumstances. Many short-term matings might be successful for some men; others might try to find and keep a single mate, investing their effort in rearing her offspring. Recent evidence suggests that men with features signaling genetic benefits to offspring should be preferred by women as short-term mates, but there are trade-offs between a mate's genetic fitness and his willingness to help in child-rearing. It is these circumstances and the cues that signal them that underlie the variation in short- and long-term mating strategies between and within the sexes.

A considerable proportion of the population in post-industrial societies experiences substantial difficulties in the domain of mating. The current research attempted to estimate the prevalence rate of poor mating performance and to identify some of its predictors. Two independent studies, which employed a total of 1,358 Greek-speaking men and women, found that about 40% of the participants experienced poor performance in either starting or keeping an intimate relationship, or in both areas. Furthermore, emotional intelligence, Dark Triad traits, jealousy, and attachment style were found to be significant predictors of mating performance. In particular, higher emotional intelligence and narcissism were associated with higher performance in mating, while higher psychopathy, jealousy and an avoidant attachment style were associated with lower mating performance.

Basking sharks Cetorhinus maximus tend to aggregate in summer at favoured locations along Britain and Ireland's west coast. Sharks have been described approaching and close-following one another, often to one side. This has been interpreted as putative pre-mating behaviour. At aggregation sites around the Inner Hebrides we used boat-based observation and in-water and overhead drone video-photography to document behaviour and to determine the sex of individuals. It was confirmed that a shark will frequently move purposely towards another from a distance and swim to maintain a position either directly behind or closely to one side of a conspecific for short periods. Contrary to expectation, we found no relationship between the sex of a shark or its size and close-following. This suggests that following behaviours are not mainly related to courtship. Further, abrasions on the nose suspected to be related to male behaviour were found to occur on both sexes, although abrasions on pectoral fins, similarly suggestive of mating-related behaviour, were predominantly on females. Breaching by basking sharks has also been proposed as a means of attracting the opposite sex. We observed breaching by solitary sharks but commonly by sharks within aggregations, and at other times by more than one shark on the same day at the same time; but there was not any clear evidence to indicate that breaching is primarily related to mating. More likely individuals show close following chiefly for feeding-related hydrodynamic advantage. It remains plausible however that mature sharks make use of feeding aggregations to initiate pre-courtship behaviour.

Because immune defenses are often costly employed, insect immunocompetence cannot be always maintained at its maximum level. Here, the oriental fruit fly, Bactrocera dorsalis (Hendel), was used as a study object to investigate how its immune defenses varied with the developmental stage change and mating access. Our data indicated that both phenoloxidase (PO) activity and antibacterial activity significantly increased from new larvae to pupae but decreased in adults after emergence. Furthermore, both the PO activity and antibacterial activity in the hemolymph of copulated male and female adults were dramatically higher than that of virgin male and female ones, respectively. It provided the evidence that copulation could increase the magnitude of immune defense in hemolymph of B. dorsalis. Together, these results suggest that B. dorsalis possess a flexible investment strategy in immunity to meet its specific needs based on the endo- and exogenous factors, such as their distinct food source and living environments.

Reproduction remains poorly understood in the Onychoteuthidae, with information previously published on only six of the ~25 species, from three of the seven genera. Herein new information is presented for a further five species from four genera: mated and spent females are reported from the genera Onychoteuthis, Onykia, Notonykia and Callimachus, and the morphologies and locations of implanted spermatangia for the species Onychoteuthis meridiopacifica and Onykia aequatorialis are provided. Males of the genus Onychoteuthis are found to implant spermatangia within longitudinal cuts in the female's mantle surface, while males of Onykia implant individual spermatangia into the female's mantle at various locations, without a specific associated wound. These different implantation strategies are discussed in the context of mating and fertilization. A bulb-like structure at the aboral end of the spermatangium, possibly unique to the genus Onychoteuthis, is also described and examined and its function discussed. All onychoteuthids examined herein are observed to undergo extreme late-life physical degeneration.

Pheromone and light traps have often been used in ecological studies of two major noctuid pests of agriculture in Australia, Helicoverpa armigera and H. punctigera. However, results from these two methods have rarely been compared directly. We set pheromone and light traps adjacent to or amongst cotton and various other crops for 10–11 years in the Namoi Valley, in northern New South Wales, Australia. Catches in pheromone traps suggested a major peak in (male) numbers of H. punctigera in early spring, with relatively few moths caught later in the summer cropping season. In contrast, (male) H. armigera were most abundant in late summer. Similar trends were apparent for catches of both male and female H. armigera in light traps, but both sexes of H. punctigera were mostly caught in mid-summer. For both species, males were more commonly caught than females. These catch patterns differed from some previous reports. At least three generations of both species were apparent in the catches. There was some evidence that the abundance of later generations could be predicted from the size of earlier generations; but, unlike previous authors, we found no positive relationships between local winter rainfall and subsequent catches of moths, nor did we find persuasive evidence of correlations between autumn and winter rainfall in central Australia and the abundance of subsequent 1st generation H. punctigera moths. Female H. punctigera were consistently more mature (gravid) and more frequently mated than those of H. armigera. Overall, our results highlight the variability in trap catches of these two species and question the use of trap catches and weather as predictors of future abundance in cropping regions.

Ecological immunology is based upon the notion that activation and use of the immune system is costly and should thus be traded off against other energy-demanding aspects of life history. Most of the studies on insects that have examined the possibility that mating results in trade-offs with immunity have shown that mating has immunosuppressive effects. The connection between mating and immunity has traditionally been investigated using indirect measures of immunity. However, studies that have assessed the effects of mating on the resistance against real pathogens have had conflicting results. A previous study on Tenebrio molitor showed that copulation decreases phenoloxidase activity in the haemolymph, and concluded that copulation corrupts immunity in this species. In the present study we tested whether mating also affects the ability of T. molitor to resist the entomopathogenic fungus, Beauveria bassiana. Interestingly, we found that mating enhanced resistance against the fungal infection and that the effect was stronger on males than females. Furthermore, we found that male beetles were overall more susceptible to the fungal infection than were females, indicating an immunological sex difference in immunity. Our study highlights the importance of the use of real pathogens and parasites in immuno-ecological studies.

Considerable diversity has been found in the reproductive behaviour of benedeniine (capsalid) monogenean parasites. Mating has been observed in Benedenia sp. 1 from the gills of Lutjanus carponatatus; externally attached spermatophores are not involved and parasites indulge in mutual cross-insemination with intromission. In contrast, there is evidence of spermatophore involvement in Benedenia sp. 2 from the fins of Lethrinus miniatus; mating was not observed but an individual was found carrying an external ovoid spermatophore attached by a stalk lodged in the vagina. In specimens of Benedeniella macrocolpa and B. posterocolpa, in which the male reproductive system was functional and the female system not fully developed, the everted cirrus was seen to be lodged in the parasite's own uterus, with, in some individuals, the tip of the cirrus inside the ootype. This is the first time that the copulatory organ has been observed inside the female reproductive tract of the same individual, not just in benedeniines but in monogeneans in general, and is also the first demonstration that monogeneans are capable of self-insemination via the uterine route.

This target article presents an integrated evolutionary model of the development of attachment and human reproductive strategies. It is argued that sex differences in attachment emerge in middle childhood, have adaptive significance in both children and adults, and are part of sex-specific life history strategies. Early psychosocial stress and insecure attachment act as cues of environmental risk, and tend to switch development towards reproductive strategies favoring current reproduction and higher mating effort. However, due to sex differences in life history trade-offs between mating and parenting, insecure males tend to adopt avoidant strategies, whereas insecure females tend to adopt anxious/ambivalent strategies, which maximize investment from kin and mates. Females are expected to shift to avoidant patterns when environmental risk is more severe. Avoidant and ambivalent attachment patterns also have different adaptive values for boys and girls, in the context of same-sex competition in the peer group: in particular, the competitive and aggressive traits related to avoidant attachment can be favored as a status-seeking strategy for males. Finally, adrenarche is proposed as the endocrine mechanism underlying the reorganization of attachment in middle childhood, and the implications for the relationship between attachment and sexual development are explored. Sex differences in the development of attachment can be fruitfully integrated within the broader framework of adaptive plasticity in life history strategies, thus contributing to a coherent evolutionary theory of human development.