Squid engage in internal fertilization, but rather than using a penis for the transference of sperm cells, the males place a packet of sperm cells, called a spermatophore, into the femaleâ€™s mantle, or body cavity; however, individual squid species exhibit variations on this general model. Shortly after this sperm transfer takes place, the female excretes fertilized eggs into the water.
Many male squid species possess long, specialized tentacles or arms for transferring spermatophores. In many cases, these tentacles break off once inside the female. Some species engage in elaborate courtship rituals that feature a “mating dance” and stunning visual displays in which the squid change colors rapidly. Females of some species only mate with one male while others are polyandrous and mate with up to three different males at three different times. In some species, the largest males are the most successful breeders while in others the males are not even as large as the females.
Most squid are semelparous, meaning that they only breed during one season before they die. While some species live long lives and are capable of breeding in consecutive seasons, many squid species experience a very high mortality rate. This makes it rare for squid to live long enough to breed twice.Learn More
The giant squid eats other sea creatures including fish. Giant squid are also known to eat other squid, although not of the same species.Full Answer >
Squid are an important food source for many different fish, including most of the large predatory species. Marlins, tuna and groupers frequently eat squid, and sharks and rays consume the mollusks as well. In addition to fish, dolphins, whales, sea mammals and oceanic birds predate on squid.Full Answer >
Squids protect themselves with several techniques and biological mechanisms to blend in with the surrounding environment, counter oncoming threats and defend themselves in the event of an attack by a predator or rival. There are approximately 500 species of squid, and all rank high in intelligence among other invertebrate animals.Full Answer >
Squid have two gills, one on the left and on the right side of their heads. The gills are part of a squid's respiratory and cardiovascular system. They are feather-like organs used to collect oxygen from water passing through them.Full Answer >