Celebrating Marine Moms

A polar bear and its cub in Arctic National Wildlife Refuge, Alaska.

Phoenix, the North Atlantic right whale whose replica hangs in the National Museum of Natural History, celebrates her 17th mother's day this year. She had her first baby in 1996 at age nine and has had many more through the years. Some whale moms will breed their entire lives while others stop early. Learn more about this mammalian menopausal mystery.

Some moms do all the heavy lifting. This mantis shrimp mom uses her clubbed claws to protect her clutch of eggs from getting poached by predators. But she isn't working entirely alone. While she egg-sits, mantis shrimp dad is out hunting for both of them.

Some moms split the load with dads. The Laysan Albatross mom and pop take turns incubating their egg for nine weeks, one sitting while the other catches fish for the both of them. After the egg hatches, they both take to sea to protect their chick, catching squid and fish for it to eat.

Dolphin moms know best, and they make sure to pass on their knowledge to their daughters. One group of Australian bottlenose dolphins uses sponges as hunting tools to root up prey from the seafloor. But only the females engage in this behavior, which is passed on from grandmother to mother to daughter.

With 100 feathers per square inch, emperor penguins have the highest density of feathers of any bird. But when all those feathers can't keep babies toasty, mom is there for a warming huddle. Mom and dad take turns keeping their chick warm. And when the chick gets hungry, it uses a special whistle to alert its parents to free it from the inter-leg lockdown.

Cardinalfish dads do their part to protect their eggs by gingerly carrying them in their mouths. However, a dad could easily swallow the whole bunch in one gulp! To keep her eggs alive, the cardinalfish mom will often lay a number of yolkless dummy eggs along with the real ones. These dummy eggs trick the dad into thinking he has more future offspring in his mouth—and thus the clutch is worth careful protection.

Much like ants or bees, in some colonies of royal snapping shrimp you'll find only one mom for the whole bunch. This queen is in charge of breeding, and everyone else is devoted to serving mom and her babies by defending the sponge where they live from intruders and raising the young ones.

For anemonefish, sex change is commonplace. The largest anemonefish living in a host anemone is female—the anemone's only maternal inhabitant—and all the smaller anemonefish are males or juveniles. When the queen anemonefish dies, the next largest male undergoes a sex change and replaces her as queen of the anemone.

Female sperm whales live in groups. Mothers must dive deep and long to find food, which leaves their calves in danger. So the moms help one another out. While one Mom is gone, the other mothers share babysitting duties until she returns.