Speaker 1: Welcome to brainstuff, a production of iHeartRadio, Hey brain Stuff
Speaker 1: Lauren Vogelbaum here. Reproduction is a weird and multitudinous process.
Speaker 1: Some fish, for example, release their eggs into the water
Speaker 1: to be fertilized without any direct contact between either parent.
Speaker 1: Some living creatures don't need two parents at all, like
Speaker 1: yeast's the kind we use to make bread that reproduce
Speaker 1: by a new organism butting right off of a single parent,
Speaker 1: or mushrooms that release spores which are like seeds, except
Speaker 1: they don't need to be pollinated to develop into a
Speaker 1: new mushroom. Even some lizards have been known to lay
Speaker 1: eggs that develop into a hatchling without having been fertilized.
Speaker 1: But in most of the higher animal kingdom, a male
Speaker 1: animal delivers its sex cells or sperm to a female animal,
Speaker 1: which keeps its sex cells or eggs inside its body,
Speaker 1: where the young are nourished and developed until the female
Speaker 1: animal gives birth. However, not so for seahorses. Male seahorses
Speaker 1: carrie and birth they're young seahorses. Sea dragons and pipefishes
Speaker 1: are a family of small marine fishes that tend to
Speaker 1: have bony armour and long snouts with fused jaws. They
Speaker 1: also have the unusual habit of leaving the gestation of
Speaker 1: their young to the males. They do this in a
Speaker 1: uterus like pouch, a complete with a placenta found in
Speaker 1: their tails. A male seahorses have this pouch on the
Speaker 1: front of their tails. The female seahorse impregnates the male
Speaker 1: by inserting eggs into that pouch, into which the male
Speaker 1: releases sperm to fertilize the eggs, and then incubates the
Speaker 1: babies for twenty four days. Researchers have found that they
Speaker 1: even provide the developing young with oxygen and nutrients during
Speaker 1: this time, like female mammals and some reptiles do. The
Speaker 1: mechanism behind this process of labor and birth was mysterious
Speaker 1: for a long time, but an Australian research team has
Speaker 1: cested out in a study published in September of twenty
Speaker 1: twenty two in the journal Placenta. The researchers reported that
Speaker 1: male seahorses labor and give birth in a way that's
Speaker 1: very different from other mothers. Female labor in birth is
Speaker 1: driven primarily by hormones like oxytocin, which can tract the
Speaker 1: smooth muscles of the uterus to push the babies out.
Speaker 1: A smooth muscle tissue works involuntarily, whereas skeletal muscles can
Speaker 1: flex and relax when the brain tells them to, which
Speaker 1: is why you can probably smile at will, but people
Speaker 1: can't go into labor whenever they want. The research team
Speaker 1: found the muscle tissue of the seahorse brood pouch did
Speaker 1: not respond to the fish version of oxytocin, but that
Speaker 1: the pouch itself contained very little smooth muscle tissue. Instead,
Speaker 1: they found that the male seahorse has three small bones
Speaker 1: at the opening of the brood pouch, where the anal
Speaker 1: fin attaches to these skeletal muscles. Female seahorses have very
Speaker 1: small or not existent anal fins. They are more prominent
Speaker 1: in males. It turns out that those anal fins and
Speaker 1: the skeletal muscles that power them are a key to
Speaker 1: the mystery of seahorse birth, as they play a role
Speaker 1: in both mating and labor for the seahorse. During courtship,
Speaker 1: the male seahorse does a little sit up style dance,
Speaker 1: a crunching and expanding his abdomen to let water into
Speaker 1: his brood pouch. He does the same thing when he
Speaker 1: goes into labor, pressing and relaxing his abdomen until his
Speaker 1: thousands of babies few fourth. So instead of smooth muscle
Speaker 1: running the seahorse birthing show, it's the skeletal muscles of
Speaker 1: the amal fin the contract to open the brood pouch
Speaker 1: of the male seahorse. More study is required to test
Speaker 1: whether seahorses consciously make the contractions happen, or if the
Speaker 1: skeletal muscles somehow override their normal rules and contract on
Speaker 1: their own. A seahorse father can give birth to as
Speaker 1: many as two thousand babies at a time. The scientists
Speaker 1: think the reason that males give birth instead of the
Speaker 1: females is because seahorse babies are often eaten by predators,
Speaker 1: and so having the male give birth allows the female
Speaker 1: time to create more eggs to be fertilized without having
Speaker 1: to wait to give birth herself, sharing that labor insures
Speaker 1: survival the species. Today's episode is based on the article Yes,
Speaker 1: malsea horses do give birth Here's how on HowStuffWorks dot Com,
Speaker 1: written by Jesslin Shields. Brainstuff is production by Heart Radio
Speaker 1: in partnership with HowStuffWorks dot Com and is produced by
Speaker 1: Tyler Klang. Four more podcasts from my heart Radio. Visit
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