Support for the Immunocompetence Handicap Hypothesis in the Wild: Hormonal Manipulation Decreases Survival in Sick Damselflies

González‐Tokman, Daniel; Munguía‐Steyer, Roberto; González‐Santoyo, Isaac; Baena‐Díaz, Fernanda; Córdoba‐Aguilar, Alex

doi:10.1111/j.1558-5646.2012.01678.x

Cited by 24 publications

(22 citation statements)

References 44 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Since parasitic rate can vary according to age in damselflies (see, for example, [34]) it was controlled in all our tests by categorizing three adult ages that have been used in previous studies of age categorization in adult damselflies (e.g. [35]): age 1 are those recently-emerged animals with soft, flexible and colourless body, zig-zag, erratic flight, and do not engage in reproductive activities; age 2 are fully sexually mature animals (as indicated by fully expressed body and/or wing colors and are already engaging in reproductive activities); age 3 are animals whose wings may be broken, and whose bodies are less intense in colour than those of age two, and show signs of pruinescence.…”

Section: Methodsmentioning

confidence: 99%

The Sicker Sex: Understanding Male Biases in Parasitic Infection, Resource Allocation and Fitness

Córdoba‐Aguilar

Munguía‐Steyer

2013

PLoS ONE

Self Cite

View full text Add to dashboard Cite

The “sicker sex” idea summarizes our knowledge of sex biases in parasite burden and immune ability whereby males fare worse than females. The theoretical basis of this is that because males invest more on mating effort than females, the former pay the costs by having a weaker immune system and thus being more susceptible to parasites. Females, conversely, have a greater parental investment. Here we tested the following: a) whether both sexes differ in their ability to defend against parasites using a natural host-parasite system; b) the differences in resource allocation conflict between mating effort and parental investment traits between sexes; and, c) effect of parasitism on survival for both sexes. We used a number of insect damselfly species as study subjects. For (a), we quantified gregarine and mite parasites, and experimentally manipulated gregarine levels in both sexes during adult ontogeny. For (b), first, we manipulated food during adult ontogeny and recorded thoracic fat gain (a proxy of mating effort) and abdominal weight (a proxy of parental investment) in both sexes. Secondly for (b), we manipulated food and gregarine levels in both sexes when adults were about to become sexually mature, and recorded gregarine number. For (c), we infected male and female adults of different ages and measured their survival. Males consistently showed more parasites than females apparently due to an increased resource allocation to fat production in males. Conversely, females invested more on abdominal weight. These differences were independent of how much food/infecting parasites were provided. The cost of this was that males had more parasites and reduced survival than females. Our results provide a resource allocation mechanism for understanding sexual differences in parasite defense as well as survival consequences for each sex.

show abstract

Section: Methodsmentioning

confidence: 99%

The Sicker Sex: Understanding Male Biases in Parasitic Infection, Resource Allocation and Fitness

Córdoba‐Aguilar

Munguía‐Steyer

2013

PLoS ONE

Self Cite

View full text Add to dashboard Cite

show abstract

“…Thus, other hormones produced by invertebrates could perform the same function as testosterone by reducing immunity while enhancing sexual signaling, and a number of studies have had mixed success in discovering such an analogous hormone. For example, juvenile hormone can promote traits important for dominance and sexual signaling while decreasing immunocompetence, and ultimately survival (Contreras-Garduño et al, 2009; Gonzalez-Tokman et al, 2012; Rantala et al, 2003). Although seemingly acting like testosterone, juvenile hormone is produced by both sexes whereas testosterone is the major sex hormone of male, but not female, vertebrates.…”

Section: Hpg Axis and Immunitymentioning

confidence: 99%

Neuroendocrine-immune circuits, phenotypes, and interactions

Ashley

Demas

2017

Hormones and Behavior

View full text Add to dashboard Cite

Multidirectional interactions among the immune, endocrine, and nervous systems have been demonstrated in humans and non-human animal models for many decades by the biomedical community, but ecological and evolutionary perspectives are lacking. Neuroendocrine-immune interactions can be conceptualized using a series of feedback loops, which culminate into distinct neuroendocrine-immune phenotypes. Behavior can exert profound influences on these phenotypes, which can in turn reciprocally modulate behavior. For example, the behavioral aspects of reproduction, including courtship, aggression, mate selection and parental behaviors can impinge upon neuroendocrine-immune interactions. One classic example is the immunocompetence handicap hypothesis (ICHH), which proposes that steroid hormones act as mediators of traits important for female choice while suppressing the immune system. Reciprocally, neuroendocrine-immune pathways can promote the development of altered behavioral states, such as sickness behavior. Understanding the energetic signals that mediate neuroendocrine-immune crosstalk is an active area of research. Although the field of psychoneuroimmunology (PNI) has begun to explore this crosstalk from a biomedical standpoint, the neuroendocrine-immune-behavior nexus has been relatively underappreciated in comparative species. The field of ecoimmunology, while traditionally emphasizing the study of non-model systems from an ecological evolutionary perspective, often under natural conditions, has focused less on the physiological mechanisms underlying behavioral responses. This review summarizes neuroendocrine-immune interactions using a comparative framework to understand the ecological and evolutionary forces that shape these complex physiological interactions.

show abstract

“…On one hand, fat reserves and muscle mass are used when a male disputes a territory, which explains their relation with territory tenancy and mating success [19]. On the other hand, both immune ability (in the form of phenoloxidase, a key component in insect immunity) [20] and fat reserves are positively correlated with survival [21], [22]. These different pieces of evidence support the notion for a fighting signal function for wing spot.…”

Section: Introductionmentioning

confidence: 77%

A Mismatch between the Perceived Fighting Signal and Fighting Ability Reveals Survival and Physiological Costs for Bearers

et al. 2014

Self Cite

View full text Add to dashboard Cite

Signals of fighting indicate an animal's intention to attack and so they serve to prevent costly aggressive encounters. However, according to theory, a signal that is different in design (i.e. a novel signal) but that fails to inform fighting intentions will result in negative fitness consequences for the bearer. In the present study we used males of the territorial damselfly Hetaerina americana, which have a red wing spot during territory defense that has evolved as a signal of fighting ability. By producing a novel signal (covering the red spot with blue ink) in territory owners, we investigated: a) the behavioral responses by conspecific males; b) survival cost and c) three physiological mediators of impaired survival: muscular fat reserves, muscle mass and immune ability. We predicted that males with the novel signal would be attacked more often by conspecifics as the former would fail to convey fighting ability and intentions adequately. This will result in lower survival and physiological condition for the novel signal bearers. We found that, compared to control males (males whose red spot was not changed), experimental males had reduced survival, were less able to hold a territory, and had a reduced muscle mass. It seems that spot modified males were not able to effectively communicate their territory tenancy, which may explain why they lost their defended sites. Our results provide support for theoretical models that a novel signal that fails to informing fighting ability may lead to a fitness cost for bearers.

show abstract

Support for the Immunocompetence Handicap Hypothesis in the Wild: Hormonal Manipulation Decreases Survival in Sick Damselflies

Cited by 24 publications

References 44 publications

The Sicker Sex: Understanding Male Biases in Parasitic Infection, Resource Allocation and Fitness

The Sicker Sex: Understanding Male Biases in Parasitic Infection, Resource Allocation and Fitness

Neuroendocrine-immune circuits, phenotypes, and interactions

A Mismatch between the Perceived Fighting Signal and Fighting Ability Reveals Survival and Physiological Costs for Bearers

Contact Info

Product

Resources

About