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The beginning of a polar bear’s (Ursus maritimus) life is certainly a unique one that requires tons of preparation. It starts from the uterus, where delayed implantation is common in order to birth their young at the best times. Mothers know well enough that you must prepare prior to giving birth, which is why females often gain up to 200 kg (441 lb) for a successful pregnancy. As if it wasn’t hard enough, females have to find maternity dens and beat the rush of other mothers before there’s none left. If not, her cubs may face winter’s extreme temperatures and harsh weather, which is definitely not a good way to survive. Digging in snowdrifts on southern-facing slopes is done often, but earthen dens are also common even though they frequently get buried in snow. The dens can range from one to seven chambers, always containing a ventilation hole for fresh air. The snow’s insulation combined with the bear’s body heat allows the den to stay warmer than the outside. Unless there’s frequent food, females give birth around once every three years. Where food is always near, cubs are bared (no pun intended) every two years. Litters of three to four are rare, so mothers typically expect only one or two. This takes a workload off, since cubs are born appearing both hairless and helpless, lacking the ability to open their eyes for quite some time. Especially during this period in their life, a mother will risk life and limb to keep her offspring out of harm’s way. A cub may continue nursing from up to 18 or 30 months of age, depending on the dependency on the mother. Mothers will feed them a varied diet of seal carcasses and whatever else they can get their paws on, and combine it with the nutrient-rich milk they get from suckling. Of course, the meat comes in after the 3 months it takes for a young polar bear to develop it’s white(ish) fur and fearsome teeth, and acclimate to the colder environment! Mommas gonna have her work set out for her by this time, because her offspring will take over a year to become successful hunters.. All through watching mommy at work. Photo credit: Greenpeace UK
What appears to be some kind of deformed fin is actually a male anglerfish (order Lophiiformes) latching onto it’s female counterpart. Living at depths up to 3600 feet  (around 1 km), you can imagine how hard it is to find a mate. Life is sparse, and you have to make special adaptations just to survive. In this case, it’s an adaptation to make the next generation possible. Scientists were baffled by anglerfish purely because every individual they caught was female.. But they soon found growths on a select few. Upon further investigation, these were males that had fused with the female’s body. They shared the same nutrients and oxygen, the male dependent on the female for survival. He basically mooches off of her success, whether it be from catching food or avoiding dangers. In return, she has basically a degenerated body attached to her for life, leaving essentially a pair of sperm-producing tentacles. Females are practically hermaphrodites, having up to six of these males hanging off of her. She is ready to breed at any given moment, whenever she so chooses.  Photo credit: Solvin Zankl
Let’s talk octopus reproduction! That’s right, we’re learning how this cute little Cephalopod was made.  Male octopuses have a special arm, called a hectocotcylus, to insert spermatophroes (packets of sperm) into the female’s mantle cavity. On most octopus, it’s normally the third right arm. Males typically die within a few months of mating. In some species, females are capable of keeping the sperm alive inside of her for weeks until her eggs mature. After fertilization, the female will lay around 200,000 eggs (but may vary dramatically) and hangs these eggs in strings from the ceiling of her lair, or individually attatches them to substrate, once again depending on the species. She will then take a one month break from hunting in order to guard her eggs from predators, and blow currents of water over her eggs for oxygen. She may even go so far as to ingesting her own arms for sustenance. By the times the eggs hatch, the mother is too weak to fend for herself and will often be attacked by animals, unable to fight back. The baby octopuses will drift in clouds of plankton, feeding on copepods, larval crabs, and larval starfish until they can descend to the ocean bottom, and the cycle will repeat. Photo credit: Michael Bok
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