Having found that males of the bioluminescent species Taningia danae use their beaks and sharp claws to slice two-inch-deep wounds into their partners, and sperm packets or spermatophores, are then inserted into the female using a penis-like appendage.
The study was headed by Henk-Jan Hoving, a Ph.D. student at the University of Groningen in the Netherlands and also found that males of Moroteuthis ingens species were found to have sperm packets that, once deposited onto a female, burrow into the body.
"The spermatophores penetrate the skin independently," National Geographic quoted Hoving as saying."They probably do that with the help of an enzyme-like substance that dissolves tissue," he added.
While studying the bizzare mating rituals, the scientists also came across the first ever transgender squid called Ancistrocheirus lesueurii. Some males of the species appeared like females in size and also had developed female sexual glands. According to Hoving, the males did this to be able to go unnoticed among potential mates.
The other explanation could be that waterborne residues from human contraceptive pills or other "gender-bending" pollutants might be harming squid. The most stunning part of the study was the discovery that the eggs fertilize internally.
Contrary to the old belief that female squids release their eggs into the water to be fertilized by sperm left on their bodies by males, it is now observed that females of the mini-squid Heteroteuthis dispar have an internal sperm storage sac that connects to the oviducts, the tubes through which eggs pass.
"Spawning and fertilization is usually external in squid, but this species suggests it can happen internally," Hoving said. "The sperm is able to migrate toward the eggs before they leave the body," he added.
Mike Vecchione of the Smithsonian''s National Museum of Natural History in Washington, D.C., called the internal fertilization find "remarkable." The discovery of male squid with female characteristics is also "completely new," he added. AGENCIES