Since the origin of the world, in the animal kingdom, females have given birth and nurtured their spawn. Yet, some exceptions exist where modern male fish care for eggs and young! Who are these underwater caring fathers outdoing human dads?
The best underwater dads
The Cardinal Fish: the male fish who looks after his babies in his mouth
Cardinal Fish or Banggai are mouthbrooders, where males carry eggs in their mouth. The female will release an egg mass close to the chosen male and after the male fertilises the eggs, he will take them into his mouth to carry them during the incubation period, until the fry are ready to hatch. As he incubates the eggs the male cardinal fish will open its mouth to rotate the egg mass from time to time, to keep them clean and aerated. At times he will partially expel the eggs before sucking them back in. The male broods the eggs in his mouth for up to 30 days, during which it does not feed! Some males may show partial brood cannibalism, by eating up to 30% of their brood, during this period!
Crédit: Jim Catlin Photography
The Lumpsucker: the most self-sacrificing dad
The lumpsucker, also known as lumpfish, sea hen, henfish, heads in the spring to very shallow inshore waters to breed. The female will lay the eggs which are fertilized by the male. The male lumpfish guards the egg mass, never leaving it except to drive off some intruder. When the tide’s in, he uses his fins or tail to keep water circulating over all of the eggs. When the tide recedes, however, the lumpsucker goes the extra mile by staying put. He remains with his eggs by attaching himself to the rocks with a sucker formed from his pelvic fins, a kamikaze move exposing him to hungry gulls and crows!
The Seahorse: the male fish who gives birth
Seahorses are the only fish that experience true male pregnancy. When mating, female seahorses deposit their eggs, between 100 and 200, into the male’s pouch. The female leaves right after the mating. The male incubates the eggs for a period of up to 45 days, regulating the temperature and caring for them until they hatch. When the tiny seahorses are ready to be born, the male undergoes muscular contractions to expel the young from the pouch which can last up to 4 days… The dad may mate and receive a new load of eggs within hours or days!
The Sea Spider: the male fish who carries the babies
The future sea spider or pycnogonid dad, small marine animal living in Northern European coastal waters, collects the eggs and carries them until hatching. Each male sea spider gathers the fertilized eggs into a ball using a pair of specialized appendages ovigers. Glands on the legs of the male sea spider release a cementing agent, which holds the egg mass together. The eggs remain attached to the male’s ovigers until they hatch. Over one season, males may carry several egg masses!
The stickleback: the male fish who builds and takes care of the nest
The male stickleback builds a nest with plant material, sand, and various debris which he glues together with a sticky substance secreted from his kidneys. He then attracts an egg-laying female with a zig-zag courtship dance and bright red colourings to his nest where she deposits 40 to 300 eggs. The male then takes care of the developing eggs by fanning them with his fins to provide oxygen. Once the eggs have hatched, he protects the small fry and teaches them self-defence from predators by chasing them. Model dad? Not quite, because like the cardinal fish, stickleback males sometimes consume their own eggs!
The Emperor Penguin: the male who stays behind and incubates the egg
At the beginning of Antarctica winter, emperor penguins traverse up 100 km across the ice to reach stable breeding grounds in extreme weather conditions. Upon arriving on the breeding grounds, emperor penguins mate, and two months later the female lays an egg. Once the egg is hatched, the female will pass the egg to the male to incubate. As there are no nesting supplies available on the ice mass, emperor penguins must create a safe, warm environment for the eggs using their own bodies. Careful to keep the egg sheltered, the male will balance the egg on his feet and cover it with a warm layer of feathered skin called a brood pouch. The female will return to the sea to hunt and feed for two months while the male stays behind and keeps the egg warm. Over the next couple months, the male emperor penguins must cope with the worst weather conditions on earth, all the while eating nothing. To withstand the harsh winds and blizzards, the penguins huddle together in groups. They take turns moving towards the inside of the pack, where it is warmer, thereby sustaining the entire group. Once the females arrive back at the colony, they regurgitate food for the hatchings to eat. At this time, the males can finally return to sea to fish, and the females will continue to care for the chicks. In the four months of travel, courtship and incubation, males may lose up to 40% of their body weight!
The Gulf Pipefish: the male fish who carries and broods the eggs
Gulf pipefish or Syngnathus scovelli is one of the only species whose males can become pregnant. The Gulf pipefish, a small 12 cm long fish that mainly lives in warm waters, is a modern and responsible dad who takes care of his offspring. He selects the eggs, and to ensure his future offspring is strong, he only keeps about 40 of them. The eggs are then laid into a special pouch in the male’s pouch and he incubates them for about 14 days until they hatch, feeding them oxygen and nutrition through the pouch.