A lioness licking her cub. An elephant twining its truck around her calf. A polar bear nuzzling its pup. These heartwarming images remind us that wild animals can be doting mothers, much like us. But in coastal waters, where survival depends on timing, camouflage and luck, motherhood takes extraordinary forms.
Consider sea anemones, the vibrant “flower animals” that sway with the tides. As relatives of jellyfish, many reproduce asexually, splitting in two to create exact replicas of themselves. Others are “broadcast spawners,” releasing gametes—sperm from males, eggs from females—into the open water. Fertilized in the water column, these eggs sink to the seafloor and develop into larvae. No further parental care necessary.
The brooding anemone (above) lives up to her name. Her offspring develop inside her gastrovascular cavity, emerging as miniature anemones. Clinging to her body, much like baby koalas gripping a tree, they rely on their mother for protection and nourishment. After several weeks to months, depending on the species, the juveniles are strong enough to break away and live independently.
Sea stars also employ diverse reproductive strategies. Many broadcast spawn, but the brooding sea star is a devoted parent. After capturing sperm released into the water, she tucks the fertilized eggs under her five arms or into a specialized pouch near her mouth. Shielding them from predators and harsh sunlight, she moves gently to forage while allowing water to circulate and aerate the eggs—a marine multi-tasking marvel.
Dungeness crabs follow a different path. Mating typically occurs after a female molts, when her shell is soft. The male transfers sperm to her body and then skitters away. The female, a single parent in a sea of predators, places a “sponge”—a mass of thousands of fertilized eggs—beneath her abdomen, where her curved tail flap shields them. For two to four months, she waves specialized appendages to oxygenate and clean the eggs. Once hatched, the larvae drift in the water column as zooplankton before settling on the seafloor to transform into miniature crabs.
No marine mother sacrifices more than the octopus. As his one and only contribution, a male deposits a sperm packet into a female’s mantle cavity, where it can remain for months. Once she finds a safe place, often a cave or rock overhang, she strings hundreds to thousands of tiny eggs into translucent, grape-like clusters suspended from the ceiling. For months (up to twelve in species like the giant Pacific octopus), she forgoes food as she zealously guards and grooms her eggs. When they hatch, the exhausted and emaciated mother dies, her life culminating in this ultimate act of devotion.
Even broadcast mothers like abalone, who release millions of eggs during spawning, can provide an extra boost. Research from the Bodega Marine Laboratory and Reserve has revealed a subtle maternal investment. Scientists compared offspring from wild red abalone, living in the cold, turbulent waters of Northern California, to those raised in controlled abalone farms. The wild abalone’s eggs, richer in lipids and proteins, produced stronger, more resilient larvae. As one researcher put it, “It’s like a Mom packing an extra sandwich in her kid’s lunch bag for a bigger energy boost.”
Marine Moms may differ from us in many ways, but I’ve come to admire their resilience and resourcefulness. On the wind-lashed, wave-battered rocky shore, they’ve evolved strategies to ensure that their offspring—and their species—survive. Their worlds may be as small as a tidepool, but they shape the future of the ocean, one brood at a time.
Photo credit: Hollis Bewley
