Female nutritional condition affects ovarian fluid quality in guppies.
Male and female gametes are often embedded in fluids that are produced by gonads and other reproductive tissues. Female reproductive fluids, usually called ovarian fluid (OF), which often constitute a relevant volumetric component of the egg mass, are rich in ions, sugars and proteins, and are involved in several functions, from protecting gametes to facilitating fertilization, and often act as mediators of post-mating sexual selection. Despite their applied and evolutionary importance, we know virtually nothing about the costs of female reproductive fluid production. We investigated the effect of nutritional condition on OF quality by experimentally manipulating the diet of two groups of female guppies (Poecilia reticulata) which were maintained for 20 days either on a restricted diet or had ad libitum access to food. In this species, OF enhances sperm swimming longevity and velocity (a predictor of sperm competition success) and mediates post-copulatory inbreeding avoidance. We found that sperm velocity was significantly lower in the OF of diet-restricted females, indicating that OF quality is dependent on female nutritional condition. Our results demonstrate that OF represents a non-trivial component of female reproductive investment and provides a tool to investigate which OF constituents are involved in modulating OF-sperm interactions and fertilization.
['Cardozo|Gabriela|G|', 'Pilastro|Andrea|A|0000-0001-9803-6308']
D000824:Animal Nutritional Physiological Phenomena D000818:Animals D001826:Body Fluids D004032:Diet D005260:Female D007178:Inbreeding D008297:Male D052586:Mating Preference, Animal D009752:Nutritional Status D010053:Ovary D011036:Poecilia D013081:Sperm Motility
reproduction sperm velocity computer-assisted sperm analysis post-copulatory sexual selection sperm–female interaction