Frequently mated males have higher protein preference in German cockroaches. (30th July 2018)

• Record Type: Journal Article
• Authors: Jensen, Kim; Silverman, Jules
• Is Part Of: Behavioral ecology. Volume 29:Number 6(2018)
• Page Start: 1453
• Page End: 1461
• Publication Date: 2018-07-30
• Subjects: ejaculate cost -- lifetime reproduction -- mating rate -- nuptial gift -- optimal foraging -- selective feeding; Animal behavior -- Periodicals; Behavior evolution -- Periodicals; Ecology -- Periodicals; Psychology, Comparative -- Periodicals; 591.5
• DOI: 10.1093/beheco/ary104
• Languages: English
• ISSNs: 1045-2249

Abstract

Abstract : Males require protein for ejaculates. We show that male cockroaches select a higher ratio of protein in their diet if they mate frequently. Our study furthermore shows that males select a much higher proportion of carbohydrate than females of the same species, which contradicts the hypothesis of intralocus sexual conflict. Males thus prefer a high-carbohydrate diet but respond actively to their mating status by adjusting feeding preferences according to requirements for future mating opportunities. Abstract: Protein is an abundant nutrient in sperm, and males therefore expend protein every time they mate. In addition, many males provide the female with a nitrogen-rich nuptial gift during mating, which often increases female fertility by supplementing her pool of limiting nutrients. However, it is unknown whether males compensate for the nitrogen cost of mating by increasing their preference for protein, which would facilitate the production of new sperm and nuptial gift material. Using artificial diets, we investigated whether male German cockroaches ( Blattella germanica ) would compensate for nitrogen expenses of mating by increasing protein preference when given the opportunity to self-select their diet from complementary foods differing only in protein and carbohydrate content. We distributed adult males across 4 mating regimes differing in the frequency of mating opportunities with receptive females and measured protein and carbohydrate consumption as well as reproductive output over the lifespan of each male. Receptive females were either never available (no mating opportunity), or they were available overnight at a frequency of each 28 days (rare mating opportunities), each 14 days (occasional mating opportunities), or each 7 days (frequent mating opportunities). Males selected highly carbohydrate-biased diets. However, males that mated more frequently had higher consumption and reproduction and self-selected higher lifetime protein to carbohydrate ratios. Our study demonstrates that male German cockroaches actively select a more protein-biased diet that compensates for their nutritional requirements following mating. The study shows that male mating significantly affects foraging decisions for specific nutrients to compensate for the expenses of mating.