Longevity cost of remaining unmated under dietary restriction

Abstract

Summary1. Increases in longevity from dietary restriction (DR) have been linked to the evolution of physiological strategies for maintaining lifetime reproductive output despite periods of nutritional deficiency. If this is the case, then reproductive life history and mating status should determine whether or not dietary restriction increases longevity. 2. We investigate the effects of DR and mating status (mated or unmated) on longevity and lifetime reproductive output and explore mechanisms underlying these patterns by measuring resting energetic rates and changes in mass over time. We study iteroparous female Australian redback spiders (Latrodectus hasselti), which are known to tolerate periods of starvation (ecologically relevant DR) in nature. . Most strikingly, mated females (whether DR or not) had higher longevity than unmated females. 4. Mated females rapidly decreased their resting energetic rates and stopped egg production under DR. Once feeding returned to normal, resting energetic rates of mated females increased immediately, egg sac production continued and there was no net decrease in lifetime reproductive output relative to mated females without DR. 5. This shows DR increases longevity for mated females, but there is a longevity cost of remaining unmated, which may arise because unmated females (regardless of diet) maintained high energetic rates. This may be an evolved pattern of physiological support for reproductive readiness which exerts a fitness cost when mating is delayed. Taken together, these results suggest positive effects of DR on longevity critically depend on reproductive life history (iteroparity or semelparity) and individual mating status.

How to get the most bang for your buck: the evolution and physiology of nutrition-dependent resource allocation strategies

“…It is thus possible to see how hormonal signalling may regulate optimal allocation and account for evolution of diverse resource allocation patterns. [100]; in wildliving D. melanogaster, larval age and larval weight predicted survival in temperate and tropical regions, respectively [101]; and in redback spider, dietary restriction extended lifespan in mated, but imposed cost in unmated females [102]. These examples suggest multiple mechanistic possibilities defining a given phenotypic trade-off in different species or within species in different environments.…”

Differential Aging of Bite and Jump Performance in Virgin and Mated Teleogryllus Commodus Crickets

“…Consequently, it is of interest to understand the effects of diet in conjunction with key life‐history events such as mating, which may alter resource allocation, and hence patterns of aging, on male and female performance traits. Indeed, mating status and mating regimes have been repeatedly shown to have important (and often sex‐specific) effects on aging and longevity in a variety of animal species (e.g., Aigaki and Ohba 1984; Paukku and Kotiaho 2005; Stolz et al 2010). Given the general importance of whole‐organism performance to a variety of ecological tasks in numerous selective contexts, ranging from mate and/or territory acquisition and defense (Husak et al 2006, 2008; Hall et al 2010b) to escape behavior (Lailvaux et al 2003; Irschick et al 2005; Dangles et al 2007), dispersal (Phillips et al 2006), and feeding (Vincent et al 2005; Herrel et al 2001, 2006), an understanding of the life‐history factors affecting performance traits in males and females over individual lifetimes is essential to understanding both the ecology and evolution of performance traits.…”

Low metabolic rates in primitive hunters and weaver spiders

“…This low level of resting metabolic rate may be an important factor that allows certain species to survive and save energy for long periods without food (Anderson, ; Tanaka & Ito, ; Nentwig, ). Also, spiders are able to reduce their metabolic rates to lower values than usual during periods of food restriction, which can reach values close to 50% of those for a well‐fed spider (Ito, ; Miyashita, ; Anderson, ; Tanaka & Ito, ; Canals et al ., ; Stoltz et al ., ; Canals et al ., ).…”

“…A low resting metabolic rate may be a factor that allows spiders to extend their survival without food (Tanaka & Ito, Canals et al, 2007;Nentwig, 2013). In addition, spiders may reduce their metabolic rate significantly when they experience periods of food limitation (Ito, 1964;Miyashita, 1969;Anderson, 1974;Tanaka & Ito, 1982;Canals et al, 2007;Phillip & Shillington, 2010;Stoltz et al, 2010;Canals et al, 2011). Lighton et al (2001) propose that spiders have metabolic rates similar to those of other land arthropods.…”