Dataset Information

Female ornamentation and the fecundity trade-off in a sex-role reversed pipefish.

ABSTRACT: Sexual ornaments found only in females are a rare occurrence in nature. One explanation for this is that female ornaments are costly to produce and maintain and, therefore, females must trade-off resources related to reproduction to promote ornament expression. Here, we investigate whether a trade-off exists between female ornamentation and fecundity in the sex-role reversed, wide-bodied pipefish, Stigmatopora nigra. We measured two components of the disk-shaped, ventral-striped female ornament, body width, and stripe thickness. After controlling for the influence of body size, we found no evidence of a cost of belly width or stripe thickness on female fecundity. Rather, females that have larger ornaments have higher fecundity and thus accurately advertise their reproductive value to males without incurring a cost to fecundity. We also investigated the relationship between female body size and egg size and found that larger females suffer a slight decrease in egg size and fecundity, although this decrease was independent of female ornamentation. More broadly, considered in light of similar findings in other taxa, lack of an apparent fecundity cost of ornamentation in female pipefish underscores the need to revisit theoretical assumptions concerning the evolution of female ornamentation.

SUBMITTER: Mobley KB

PROVIDER: S-EPMC6194251 | biostudies-literature | 2018 Sep

REPOSITORIES: biostudies-literature

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Female ornamentation and the fecundity trade-off in a sex-role reversed pipefish.

Mobley Kenyon B KB Morrongiello John R JR Warr Matthew M Bray Dianne J DJ Wong Bob B M BBM

Ecology and evolution 20180829 18

Sexual ornaments found only in females are a rare occurrence in nature. One explanation for this is that female ornaments are costly to produce and maintain and, therefore, females must trade-off resources related to reproduction to promote ornament expression. Here, we investigate whether a trade-off exists between female ornamentation and fecundity in the sex-role reversed, wide-bodied pipefish, <i>Stigmatopora nigra</i>. We measured two components of the disk-shaped, ventral-striped female or ...[more]

PMID: 30377519

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Project description:Female sex workers are a structurally vulnerable population, including critical insecurity such as having access to food and shelter. This risk may be heightened among individuals who enter sex work as minors. However, the reasons for entering sex work as a minor and the long-term structural risk implications are poorly understood. Here, we investigated the reasons for and long-term impact of trading sex before the age of eighteen on women's structural vulnerability among a cohort of 250 cisgender women involved in street-based sex work in Baltimore City, Maryland, USA. We used logistic regression to explore the role of age of entry on two structural vulnerability outcomes of interest (homelessness and recent food insecurity in the past 3 months). Overall, 73% of women entered the sex trade to get drugs, 36% of women entered to get basic necessities such as food or housing, and 17% of women entered to support their children or family. Of significance, 21% of those aged < 18 years at entry reported being either coerced, threatened, pressured, misled, tricked, or physically forced into trading sex compared to 5% in those who entered at an older age group (p value < 0.001). In adjusted analysis, women who first trade sex before the age of 18 had 4.54 increased odds of experiencing recent homelessness (95% CI 1.92-10.70) and had 3.14 times increased odds of experiencing recent food insecurity (95% CI 1.42-6.94). Those who entered as minors were also more likely to be HIV positive (11.3% vs 3.6%, p value = 0.02). This study highlights that those who trade sex at a younger age experience an ongoing cumulative vulnerability in comparison to those entering over the age of 18. These findings call for additional research into a more detailed understanding of young women's entry into the sex trade and trajectory. A focus on the importance of policy changes and structural interventions that directly alleviate young people's socio-economic disadvantage is needed.

Dataset Information

Female ornamentation and the fecundity trade-off in a sex-role reversed pipefish.

Publications

Female ornamentation and the fecundity trade-off in a sex-role reversed pipefish.

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