Sexually mature cuttlefish are attracted to the eggs of conspecifics.

Cuttlefish typically are solitary, but form aggregations to spawn. We tested the hypothesis that bioactive factors in the eggs of conspecifics may facilitate the formation of spawning groups of Sepia officinalis. Cuttlefish detected odors from cuttlefish eggs, resulting in an increased ventilation rate. Extracts from female ovaries induced the largest increase in ventilation rate, suggesting that this organ could be a potential source of the bioactive chemicals. In y-maze assays, sexually mature, but not subadult, cuttlefish, were attracted to odors of cuttlefish eggs. These data suggest that Sepia eggs could be a source of reproductive pheromones.