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.Know More
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 about Squid
Penguins reproduce as most birds do, with internal fertilization that is accomplished by putting each penguin's cloacas together. The male sprays sperm into the female's cloaca where it can then travel inside and fertilize eggs.Full Answer >
Polar bears reproduce via internal fertilization, with one male mating with several females during the mating season, staying with each for their three-day period of fertility. Mating occurs between late winter and early spring, after which gestation lasts anywhere between 195 and 265 days due to the females' ability to delay fetal development. Litter sizes range from one to four cubs but average two cubs per litter.Full Answer >
Great white sharks reproduce via internal fertilization, and fertilized eggs are retained in the body until a short while after hatching in a 12-month gestation, after which the young are born live. Prior to birth, the young may eat unfertilized eggs and smaller unborn sharks in the womb. Newborn great white sharks receive no parental care, and swim away immediately after birth.Full Answer >
Japanese spider crabs, also known by their scientific name Macrocheira kaempferi, reproduce by internal fertilization. Once a year, during the mating season between January and March, male crabs insert sperm into abdomens of female crabs with the foremost pair of their chelipeds.Full Answer >