Energetic costs of mate guarding behavior in male stream-dwelling isopods

Abstract

In the stream-dwelling isopod Lirceus fontinalis, males and females engage in a precopulatory mate guarding phase prior to mating. We examined the energetic costs of mate guarding behavior in males by separately assaying glycogen and lipid content at different time increments following mating. We found that males that had recently mated possessed reduced glycogen reserves and that these reserves were fully replenished within 36 h. Conversely, we found that male lipid reserves were unaffected by time since mating. We concluded that precopulatory mate guarding behavior is energetically costly to males and that glycogen is the energy source utilized to pay that cost. We also examined whether food deprivation during the mate guarding phase affected male energy reserves (glycogen) at the end of that phase. We found that males that were held in the laboratory and starved during mate guarding possessed reduced glycogen at the termination of the phase when compared to fed males. This reduced quantity was equivalent to the glycogen reserves of recently mated males collected from the field. We propose that food deprivation during the mate guarding phase explains the reduction in glycogen reserves at the termination of that phase. We discuss these results with reference to patterns of refuge use behavior during the mate guarding phase.

Influence of gender and season on reduced glutathione concentration and energy reserves of Gammarus roeseli

“…Indeed, in females, the decrease of lipid and glycogen contents were measured from June to September, which corresponds to the reproductive period, linked to the oogenesis process. This process involves the vitellus production (required for eggs development) which uses lipids (Rosa and Nunes, 2002), and pleopod beats (considered as brood care for juveniles oxygenation- Dick et al, 1998) which could use glycogen (short-term energy- Sparkes et al, 1996). Conversely, the high lipid content measured in February in females could be explained by the maturation period.…”

“…At the same time, we measured the energy reserves by assaying glycogen and lipid contents. Glycogen represents a short-term energy source available for current activities (Sparkes et al, 1996), whereas lipids are used for long-term storage to be used as nutrients during starvation or reproduction periods (Cargill et al, 1985). Finally, we measured the levels of malondialdehyde (MDA), a product of lipid peroxidation considered as a toxicity biomarker which reflects cellular damage.…”

Microsporidia parasites disrupt the responses to cadmium exposure in a gammarid

“…Moreover, energy reserves were estimated by measuring protein concentrations as well as total lipid and glycogen contents. The levels of glycogen are representative of the energy available for current activities (Sparkes et al, 1996) whereas lipids are stored in fat bodies and are used during starvation or reproduction periods (Cargill et al, 1985).…”

Mate guarding in the Seychelles warbler is energetically costly and adjusted to paternity risk

“…In this study on the Seychelles warbler (Acrocephalus sechellensis) I test experimentally whether mate guarding is energetically costly and whether paternity risk a¡ects the time allocated to mate guarding and to foraging in males. Despite their critical importance for testing sexual-selection models, these costs have not been examined before (see also Hixon 1987;Partridge & Endler 1987;Askenmo et al 1992;Andersson 1994;Arnqvist 1994;Watson & Lighton 1994;Alberts et al 1996;Sparkes et al 1996).…”