Common Cuttlefish Reproduction
Categorized as a shallow water cephalopod, the Common Cuttlefish, Sepia officinalis (Sepiidae), is generally found in the eastern North Atlantic, throughout the English Channel, and south into the Mediterranean Sea, though populations have also been recorded along the west coast of Africa, and as far south as South Africa.
In the spring and summer, male and females migrate to shallow, warmer waters to spawn. They exhibit elaborate courtships, wherein males attract females through spectacular displays of colored bands passing rapidly along their bodies. Males then hold their arms stiffly in a basket formation to show their virility. Similarly, females display a uniform gray color when ready to mate.
Mating in Sepia officinalis involves internal fertilization, so, eventually the male will grasp a female and mate with her. Using a modified arm, known as the hectocotylus, the male passes spermatophores to the female.
After mating, fertilized eggs are stored in the oviduct of the female until they are ready to be deposited. The female deposits eggs one by one in clusters on seaweeds, shells, or even debris. She blackens them for camouflage with the same ink that cuttlefish use to cast a smoke screen against large predators. The male often remains at her side for some time, but he has no romantic intentions. He is merely trying to prevent her from mating with another male. Mate guarding, in which males aggressively fight over and guard their females, is common.
After spawning both male and females die.
Photo credit: ©Joris van Alphen | Locality: Oosterschelde, Zeeland, Netherlands (2010)