This small fish, residing in Europe’s coastal sands, reverses typical gender roles in a brilliant way. After the female Sand Goby lays her eggs, she leaves the scene, entrusting dad with the all-important task of safeguarding their future offspring.

Enter the realm of North American waters and meet the Hardhead Catfish. This dad truly knows how to fast for a cause! After he collects the eggs in his mouth, he goes on a 60-day hunger strike until the eggs hatch.

Defying typical biology, Seahorse dads experience ‘pregnancy’. After an extended courtship dance, mom Seahorse entrusts her eggs to dad’s stomach pouch. The male Seahorse can proudly tote up to 2,000 eggs during his aquatic ‘pregnancy’.

The Cardinalfish, a mouthbrooding fish, is unique to the tropical waters near the Indonesian Banggai Archipelago. Mom releases an egg mass near dad, who fertilizes and gathers them into his mouth. During incubation, dad occasionally opens his mouth to roll the eggs around, ensuring cleanliness and oxygen supply.

Meet the Pipefish, an attentive father camouflaging in the tropical seagrass beds. Like his cousin, the Seahorse, Pipefish dad also carries the eggs in a brooding pouch, providing both protection and nourishment until they’re ready to face the world.

Siamese Fighting Fish, or Bettas, are known for their intense protective instincts. Male Bettas are expert bubble nest builders, coating each bubble with saliva to ensure it doesn’t pop. Dad Bettas are known to fight off anything to secure their precious bubble-wrapped babies!

Found in the icy waters of the Arctic and North Atlantic and Pacific oceans, the adorable Lumpsucker dads prove they’ve got the parenting skills to impress. They build nests to woo potential moms, who lay up to 350,000 eggs before returning to their solo lifestyles. Dad then steps up to protect and oxygenate the eggs during their 4-8 week incubation period.

Emperor Penguins are the epitome of a doting dad. After mom lays her egg, it’s up to the dad to become a living incubator. For four entire months, he balances the egg on his feet, tucking it snugly into his brooding pouch, bravely battling biting cold and hunger.

Made famous by a certain animated movie, the Clownfish is a meticulous caretaker. He fans the water to oxygenate his eggs and ensures their cleanliness. Clownfish dads’ protective instincts are so robust that even a bachelor will care for a stranger’s eggs. That’s a heart as big as the ocean!

Even Sea Spiders make the list of dutiful underwater dads. After fertilizing a female’s eggs, the male gathers them up and secures them onto an appendage called an oviger. He carries this precious bundle until the babies are ready to venture out on their own.