Metabolic cost of holding nuptial food gifts for male spiders

Abstract

1. In various insect and spiders, males offer nuptial food gifts to females during copulation that enhance male fitness either directly through their effects on male fertilisation success or indirectly through the nutritional benefits delivering for females. However, the physiological costs of producing these gifts remain largely unexplored.2. We examined energetic costs of holding nuptial gifts in the gift‐giving spider, Pisaura mirabilis, using stop‐flow respirometry.3. Males exhibited 37% higher metabolic rates when holding a nuptial gift than when they do not have one.4. Our findings suggest the existence of metabolic costs associated with holding a nuptial gift for males. This confirm that male condition is particularly relevant for gift‐giving and may explain the evolution of male deception for cheaper nuptial gifts.