Costly parenting: physiological condition over time and season in males of the giant waterbug Abedus dilatatus

Abstract

Parental care patterns increase offspring fitness but may drive energetic costs to parents. The costs associated with parental care can change over time, decreasing the condition of parents that experience prolonged parental care. Thus, males can modulate parental effort based in the relative fitness cost/benefit pay-offs under different stages and environmental conditions. The present study assesses the condition of parental males of Abedus dilatatus Say by measuring their lipid, glycogen and carbohydrate contents. We compare the condition in parental males that have experienced recent and prolonged care and that were also collected in the summer and winter. Waterbug males provide parental care via carrying and ventilating eggs on their back. Winter males are smaller and carry fewer eggs compared with summer males. Males with recent care and carrying more eggs present a more lipid content. However, at the end of care, males carrying more eggs present less lipids than males with smaller egg-pads. Additionally, we find that males collected in the summer present more carbohydrates than males in the winter. Moreover, larger males with prolonged care present less carbohydrates than smaller males, in contrast to males with recent care where there is a positive relationship between size and carbohydrate content. Our results suggest that parental care in A. dilatatus may be a sexually-selected trait, as has been found in related species, and further experiments could test this idea. This is the first study to provide evidence of physiological costs related to exclusive paternal care in arthropods.

The costs of being a good dad: egg-carrying and clutch size impair locomotor performance in male midwife toads (Alytes obstetricans)

“…For instance, it has been shown in arthropods that egg-carrying decreases mobility, decreases food intake and increases predator attacks (Burris, 2011;Ruhland et al, 2016). Therefore altered locomotor performance, as reported in this study, may well have significant fitness implications (Webb, 1986;Burris, 2011;Munguía-Steyer et al, 2019). Our findings are similar to the locomotor costs demonstrated in females in numerous other taxa (Ruhland et al, 2016).…”

Parental care decreases the survival of adults in the waterbug Abedus ovatus

“…Also, in these two species of Belostomatidae, it has been documented that the rate of brood pumping increases when males carry larger egg pads (Munguía‐Steyer et al, 2008). This greater parental investment leads to a more significant expenditure of energy reserves such as lipids and carbohydrates (Munguía‐Steyer et al, 2019). It is likely that in our study population, the parental males make a higher parental investment due to a higher water temperature, which could result in more increased physiological wear.…”

“…During July, August, and early September 2022, we conducted capture‐mark‐recapture surveys in the Quetzalapa River (19.863699° N, 97.987107° W; 2230 m asl), in Chignahuapan locality in the north of Puebla, Mexico. In this population, A. ovatus waterbugs are present and reproduce throughout the year but have a reproductive peak during the summer (Munguía‐Steyer et al, 2019), in fact, populations of Belostomatidae distributed in low latitudes (closer to the equator in warmer waters) tend to have more reproductive events during the year (Jara & Perotti, 2018). We delimited the study area in a transect of the river of 80 m length.…”

“…Physiological costs derived from parental care have been found in the waterbug Abedus dilatatus . In this species, encumbered males decrease their energy reserves at the end of the care period (measured as lipids), particularly when they carry large egg pads (Munguía‐Steyer et al, 2019). Although these costs may have negative effects on the survival of parental males, only two studies have evaluated the survival costs related to parental care, one of them in laboratory conditions, leaving aside predation pressures (Gilg & Kruse, 2003).…”

Benefits and costs of female and male care in amphibians: a meta-analytical approach

“…In fact, we found that forms of parental care in which parents remain stationary close to their eggs, juveniles or tadpoles impose an average negative effect on body condition while there is no average negative effect in forms of parental care in which parents are mobile, such as egg or juvenile brooding and tadpole transport or feeding. Thus, we propose that a marked reduction in foraging opportunities while caring for the offspring at a fixed location may explain why parental care negatively affects body condition in amphibians (and also certain arthropods [13,54]), but not in fish (see exceptions in [16,55]).…”