G-protein coupled receptor (Probable). Plays a role in the navigational capacity of sperm and promotes the targeting of sperm derived from males to the fertilization site in the uterus of hermaphrodites (PubMed:28662030). Expressed throughout the nervous system, in pharyngeal muscle, hermaphrodite vulval muscles and in the male tail (PubMed:28662030). Not expressed in male somatic gonads or sperm (PubMed:28662030). Reduced brood size, which is in part due to an abnormal distribution of male-derived sperm in the hermaphrodite uterus following mating, with sperm moving at a reduced velocity, reversing course frequently and accumulating at the spermathecal-uterine valve 1 hour following mating (PubMed:28662030). No visible defects in oogenesis (PubMed:28662030). Belongs to the nematode receptor-like protein srb family.