scholarly journals Serial monogamy benefits both sexes in the biparental convict cichlid

PeerJ ◽  
2019 ◽  
Vol 7 ◽  
pp. e6535 ◽  
Author(s):  
Jennifer L. Snekser ◽  
Murray Itzkowitz
Keyword(s):  
Reproductive Success ◽  
Brood Size ◽  
Parental Behavior ◽  
Convict Cichlid ◽  
Costs And Benefits ◽  
Serial Monogamy ◽  
Convict Cichlids ◽  
Amatitlania Nigrofasciata ◽  
Males And Females

Monogamy can be either long-term or serial, with new pairs formed with each breeding bout. Costs and benefits are associated with each strategy. Because biparental convict cichlids (Amatitlania nigrofasciata) typically switch mates, exhibiting serial monogamy, we tested for the costs associated with forcing individuals to remain with the same mate. Convict cichlids were observed over two successive breeding bouts, either with the same or a new, equally experienced, mate. Parental behavior did not differ between breeding bouts, nor did brood size. Surprisingly, fish that remained with their original partner for a second bout took significantly longer to produce a brood compared to fish that paired with new partners. New partners were also more likely to successfully produce a second brood than re-mated partners. This is in contrast to the majority of bird studies that show many benefits to staying with the same partner for multiple broods. In convict cichlids, there seems to be no benefit associated with remaining with the same partner and switching mates reduces duration between broods for both males and females, potentially increasing overall reproductive success.

scholarly journals Convict cichlid parents that stay with the same mate develop unique and consistent divisions of roles

PeerJ ◽  
2020 ◽  
Vol 8 ◽  
pp. e10534
Author(s):  
Jennifer L. Snekser ◽  
Murray Itzkowitz
Keyword(s):  
Division Of Labor ◽  
Cichlid Fish ◽  
Direct Care ◽  
Biparental Care ◽  
Convict Cichlid ◽  
Offspring Survival ◽  
Parental Roles ◽  
Convict Cichlids ◽  
Amatitlania Nigrofasciata ◽  
Over Time

Previous studies, largely on avian species, have suggested that pairs that are permanently monogamous and have biparental care develop a coordination over time that enhances offspring survival. If this is the case, we predicted that a parent involved in biparental care would develop a pattern of biparental care specific to a particular mate and remain consistent in that pattern over time but would lose this pattern if it were to change mates. We tested this prediction with the convict cichlid fish (Amatitlania nigrofasciata) which has biparental care that is both complex and flexible. In this species, each parent can perform all parental roles but typically shows a division of labor in which males typically defend against offspring predators while the female typically provides direct care to the offspring. At various times, the parents briefly switch roles. Our experiments revealed that pairs that remained together for two consecutive broods were more consistent in their parental behaviors, including time they spent near the intruder and in the nest compared to pairs that were comprised of individuals that had previously mated with other partners. Also individuals that remained with the same partner were also more consistent as a parental unit, maintaining their sex-specific roles of males defending aggressively against an intruder and females spending more time directly caring for young. While our experiment clearly support our prediction that individuals do develop unique coordination with specific individuals, convict cichlids in nature appear to be largely serially monogamous in which they mate only once before changing partners. Thus, it is likely this coordination may be available in many species that have biparental care but become adaptive when repeated matings become common.

The effects of numerical density of adult fish on reproduction and parental behavior in the convict cichlid fish Cichlasoma nigrofasciatum (Günther)

1978 ◽  
Vol 56 (6) ◽  
pp. 1367-1371 ◽  
Author(s):  
G. J. FitzGerald ◽  
M. H. A. Keenleyside
Keyword(s):  
Reproductive Success ◽  
Parental Behavior ◽  
Cichlid Fish ◽  
Behavioral Data ◽  
Numerical Density ◽  
Convict Cichlid ◽  
Adult Fish ◽  
Cichlasoma Nigrofasciatum ◽  
Territorial Aggression ◽  
Controlled Conditions

Basic reproductive and behavioral data were collected from pairs of Cichlasoma nigrofasciatum breeding under controlled conditions. Increasing the density of potential breeding pairs increased the level of territorial aggression and decreased reproductive success. Time spent with their young by parents did not vary consistently with density. The importance of the increase in aggression and its possible influence on reproductive success are discussed.

Heterogeneous Mental Health Consequences of COVID-19: Costs and Benefits

2020 ◽  
Author(s):  
Anthony D Mancini
Keyword(s):  
Mental Health ◽  
Health Impact ◽  
Costs And Benefits ◽  
Substantial Variation ◽  
Mental Health Functioning ◽  
Health Functioning ◽  
The Social ◽  
Mental Health Costs ◽  
Long Term Impact

In this commentary, I argue that the mental health impact of COVID-19 will show substantial variation across individuals, contexts, and time. Further, one key contributor to this variation will be the proximal and long-term impact of COVID-19 on the social environment. In addition to the mental health costs of the pandemic, it is likely that a subset of people will experience improved social and mental health functioning.

The Acceptance of Party Unity in Parliamentary Democracies

2017 ◽  
Author(s):  
David M. Willumsen
Keyword(s):  
Political Parties ◽  
Costs And Benefits ◽  
Parliamentary Democracies ◽  
Survey Questions ◽  
Ideal Policy ◽  
Central Argument ◽  
The Individual ◽  
Policy Incentives

The central argument of this book is that voting unity in European legislatures is not primarily the result of the ‘disciplining’ power of the leadership of parliamentary parties, but rather the result of a combination of ideological homogeneity through self-selection into political parties and the calculations of individual legislators about their own long-term benefits. Despite the central role of policy preferences in the subsequent behaviour of legislators, preferences at the level of the individual legislator have been almost entirely neglected in the study of parliaments and legislative behaviour. The book measures these using an until now under-utilized resource: parliamentary surveys. Building on these, the book develops measures of policy incentives of legislators to dissent from their parliamentary parties, and show that preference similarity amongst legislators explains a very substantial proportion of party unity, yet alone cannot explain all of it. Analysing the attitudes of legislators to the demands of party unity, and what drives these attitudes, the book argues that what explains the observed unity (beyond what preference similarity would explain) is the conscious acceptance by MPs that the long-term benefits of belonging to a united party (such as increased influence on legislation, lower transaction costs, and better chances of gaining office) outweigh the short-terms benefits of always voting for their ideal policy outcome. The book buttresses this argument through the analysis of both open-ended survey questions as well as survey questions on the costs and benefits of belonging to a political party in a legislature.

scholarly journals Sexual dimorphism in the long-term stability (10 years) of skeletal Class III treatment

2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Natalia Tejedor ◽  
Conchita Martín ◽  
José Antonio Alarcón ◽  
María Dolores Oteo-Calatayud ◽  
Juan Carlos Palma-Fernández
Keyword(s):  
Sexual Dimorphism ◽  
Class Iii ◽  
Class Iii Malocclusion ◽  
Skeletal Class ◽  
Term Stability ◽  
Long Term Stability ◽  
Fixed Appliances ◽  
Males And Females ◽  
Class Iii Treatment

Abstract Background Class III malocclusion is associated with high sexual dimorphism, especially in individuals older than 13 years of age, with significant differences in growth between males and females during the pubertal and postpubertal stages, and in adulthood. The aim of this research was to examine differences between males and females in long-term stability (10 years) of treatment for skeletal Class III malocclusion. Methods Thirty patients (15 males and 15 females) with skeletal Class III malocclusion, who had been treated with rapid maxillary expansion (RME) combined with face mask protraction followed by fixed appliances, were selected sequentially. Thirty patients (15 males and 15 females) with skeletal Class I and mesofacial patterns treated only with fixed appliances for dental problems served as the control group. Differences between groups and sexes were evaluated using lateral cephalograms taken at the start of treatment (T0), immediately after the end of treatment (T1), and after 10 years (T2). The long-term treatment success rate was calculated. Results Ten years after Class III treatment, overjet and overbite relapse occurred similarly in females (− 0.68 ± 0.7 mm; − 0.38 ± 0.75 mm, respectively) and males (− 1.09 ± 1.47 mm; − 0.64 ± 0.9 mm, respectively); the ANB angle and Wits appraisal became significantly more negative in males (− 1.37 ± 1.06°; − 2.7 ± 2.53 mm) than in females (− 0.18 ± 1.26°; − 0.46 ± 1.94 mm). The success rate was 73.3% in males and 80% in females. Conclusions Significant differences in the long-term stability of Class III treatment outcomes have been found between males and females, with a larger skeletal Class III relapse and lower long-term success rates in males.

scholarly journals Recent Trends in Youth Concussions: A Brief Report

2020 ◽  
Vol 11 ◽  
pp. 215013272098505
Author(s):  
Andrew T. Askow ◽  
Jacob L. Erickson ◽  
Andrew R. Jagim
Keyword(s):  
Incidence Rate ◽  
Brain Injuries ◽  
Population Based ◽  
Health Records ◽  
Medical Issues ◽  
Number Of Patients ◽  
Recent Trends ◽  
Males And Females ◽  
Large Health Care System

Objectives Concussions and mild traumatic brain injuries are important medical issues, particularly among youth as the long-term health consequences of these injuries can become increasingly problematic. The purpose of this study was to examine recent trends in diagnosed concussions among pediatric patients in a large health care system. Methods This was a retrospective, population-based epidemiology study design that queried all patient files (pediatrics included) using electronic medical health records and further stratified patients based on type of concussion, age, sex, and year from 2013 to 2018. Results Electronic health records from a cohort of 8 832 419 (nmales = 4 246 492; nfemales = 4 585 931) patient visits were assessed for concussion diagnosis and filtered for those whose concussive event led to a loss of consciousness (LOC) or not (nLOC). Of these patients, 12 068 were diagnosed with a concussion (LOC = 3 699; nLOC = 8 369) with an overall incidence rate of 1.37 concussions per 1000 patients. Overall, the number of patients diagnosed with a concussion increased by 5063 (LOC = 1351; nLOC = 3712) from 2013 to 2018. Males and females presented with similar rates of concussions 5919 (49.05%) and 6149 concussions (50.95%), respectively. Of total diagnosed concussions, 4972 (LOC = 815; nLOC = 4157) were under the age of 18 and represented 41.2% of all diagnosed concussions with an incidence rate of 6.79 per 1000 patients. Conclusion The number of concussions diagnosed appear to be on the rise with the largest number of concussions being diagnosed in those under the age of 18. Future studies should seek to determine primary causality and the long-term health implications of concussions with or without LOC.

POLYGYNY, REPRODUCTIVE SUCCESS AND CHILD HEALTH IN RURAL ETHIOPIA: WHY MARRY A MARRIED MAN?

2006 ◽  
Vol 39 (2) ◽  
pp. 287-300 ◽  
Author(s):  
MHAIRI A. GIBSON ◽  
RUTH MACE
Keyword(s):  
Reproductive Success ◽  
Male Reproductive Success ◽  
Family Status ◽  
Rural Ethiopia ◽  
Younger Age ◽  
Married Individuals ◽  
Males And Females ◽  
Child Nutritional Status ◽  
And Child Health ◽  
Better Than

Summary.This study examines the reproductive success of men and women in rural Ethiopia as a function of their marital status, specifically by comparing polygamously and monogamously married individuals. In line with predictions from evolutionary theory, polygamy is beneficial to male reproductive success (i.e. producing larger numbers of surviving offspring). The success of polygamously married females depends on wife rank: the first wives of polygamous husbands do better than monogamously married women and much better than second or third wives. These effects are mirrored in child nutritional status: the children of second and third wives have lower weight for height. Due to potential, largely unmeasurable differences in marriageability (quality) between individuals, it was not possible to support a model of either resource-holding polygyny combined with female choice or female coercion into unwanted marriages. First wives of polygamously married men marry at a younger age and attract a higher brideprice, suggesting that both the males and females in the marriage are likely to be of higher quality (due to wealth, family status or some other factor such as beauty). Unions that end up monogamous are likely to be between slightly lower quality individuals; and second and third wives, who marry at the oldest ages and attract the lowest brideprice, may be ‘making the best of a bad job’. The relatively long gap between first and second marriages may mean that first wives of highly marriageable males can enjoy considerable reproductive success before their husbands marry again.

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