Speaker 1: Welcome to Brainstuff, a production of iHeartRadio. Hey, Brainstuff, Lauren
Speaker 1: Bogelbaum here. Lobsters are odd creatures. Their appearance has earned
Speaker 1: them the nickname cockroaches of the sea, and yet they're
Speaker 1: considered a delicacy by people around North America and Europe,
Speaker 1: which is where the cold water lobster Genus Homerus resides,
Speaker 1: which is the one we're talking about today. As we've
Speaker 1: discussed on the show before, they haven't always been so prized.
Speaker 1: Lobsters were so abundant around New England during the seventeen
Speaker 1: and eighteen hundreds that their meat was fed to pigs
Speaker 1: and some indentured servants in Massachusetts we're so sick of
Speaker 1: eating it that they went to court to prevent their
Speaker 1: bosses from feeding them lobster more than three times a week,
Speaker 1: and they won. But whatever you think of them, lobsters
Speaker 1: aren't quite sophisticated critters. Today, let's talk about how they
Speaker 1: interact with the watery rolled around them, including why they
Speaker 1: don't age, making them biologically immortal, though not functionally. But okay,
Speaker 1: let's start a little bit more granular. Lobsters don't see
Speaker 1: particularly well, but they make up for it in their
Speaker 1: senses of taste, smell, and touch. A lobster has four
Speaker 1: spindly antennay and sensing hairs that allow it to smell
Speaker 1: amino acids in the waterlike those given off by prey.
Speaker 1: Lobsters are carnivores that will hunt and eat pretty much
Speaker 1: anything they can get their claws on. They're even known
Speaker 1: to munch on their vulnerable lobster brethren, though that's more
Speaker 1: common in captivity, and it's also why captive lobsters will
Speaker 1: have rubber bands put on their claws. Lobsters will sometimes
Speaker 1: bury their catch and eat it over several days. They
Speaker 1: grind up their food using titeness teeth like things called
Speaker 1: a gastric mill that's located in the first of their
Speaker 1: two stomachs. But that aforementioned excellent sense of smell isn't
Speaker 1: restricted to finding prey. They also use it to identify
Speaker 1: other lobsters, mostly via urine, which they excrete from openings
Speaker 1: on their face. Yep, lobsters pee out of their faces
Speaker 1: for behavioral purposes. A lobster excretes waste from a few
Speaker 1: spots on its body, but it urinates out of openings
Speaker 1: on its face called nephrifhores, and it's not just about
Speaker 1: getting rid of toxins. Lobsters urinate in each other's faces
Speaker 1: during fights to express themselves literally, and female lobster's urine
Speaker 1: contains pheromones to get male lobsters relaxed and in the mood.
Speaker 1: A part of the lobster mating process involves a female
Speaker 1: lobster repeatedly urinating into the shelter belonging to the male
Speaker 1: lobster that she hopes to mate with. By the way,
Speaker 1: I know what Phoebe says on friends, but lobsters don't
Speaker 1: mate for life. Their relationships last about two weeks anyway.
Speaker 1: Speaking of the reproduction process, female lobsters practice reproductive planning.
Speaker 1: A female lobster chooses her mate and makes the first moves,
Speaker 1: and then can carry around a male's live sperm with
Speaker 1: her for up to two years before using it to
Speaker 1: fertilize her eggs. She'll have some tens of thousands of eggs,
Speaker 1: so she might collect sperm from multiple males before going
Speaker 1: ahead with fertilization. The survival of her spawn depends on
Speaker 1: the environment she chooses for them, so it's good that
Speaker 1: she's picky out of every fifty thousand eggs she lays.
Speaker 1: Only two will live long enough to become an adult
Speaker 1: lobster of catchable size, not two thousand, just two. A
Speaker 1: lobster's early life is fraught with danger because they start small,
Speaker 1: and we're not the only ones that find them tasty.
Speaker 1: When they hatch. They are tiny, about the size of
Speaker 1: a mosquito, and they don't resemble adult lobsters as much
Speaker 1: as miniature dark crystal era hensing creations. Their gills are
Speaker 1: on the outside of their bodies and they don't have
Speaker 1: a shell yet, and they pretty much float around near
Speaker 1: the surface of the ocean eating plankton. They'll go through
Speaker 1: a few metamorphoses over the course of a month or
Speaker 1: so before they migrate to the ocean floor and start
Speaker 1: to look and behave like lobsters, you know, an armored
Speaker 1: skeleton on the outside of their body instead of on
Speaker 1: the inside, with a large, powerful tail, and ten legs total,
Speaker 1: with claws on the first four, including a large asymmetrical
Speaker 1: pair up front. That's right. Most lobsters have a dominant
Speaker 1: front claw, meaning they're either right clawed or left clawed.
Speaker 1: The dominant one is referred to as the crusher and
Speaker 1: it's bigger and strong enough to crack open the shells
Speaker 1: of prey. The smaller claw, called the cutter or caesar,
Speaker 1: grabs food and shreds it for consumption. But some lobsters
Speaker 1: may have two crushers or two cutters and use them interchangeably. However,
Speaker 1: lobsters are not all that attached to their limbs. Literally.
Speaker 1: They can detach a leg, claw, or antenna in an emergency.
Speaker 1: This is called a reflex amputation. It's not a big
Speaker 1: deal because they can grow it back during their molting cycle.
Speaker 1: A lobsters must molt in order to grow, splitting and
Speaker 1: shedding each hard piece of their carapas. If they've lost
Speaker 1: a limbs since their last molt, they'll grow it back
Speaker 1: as they grow a new, larger shell. They'll start by
Speaker 1: eating their molted shells as they're full of the calcium
Speaker 1: they need to grow the new one. But this brings
Speaker 1: us to perhaps the weirdest thing about lobsters. Given everything
Speaker 1: we know about life as we know it, lobsters show
Speaker 1: no apparent signs of aging. They don't slow down or
Speaker 1: become weaker or more susceptible to disease. They don't become infertile.
Speaker 1: Older lobsters are actually more fertile than younger ones. For
Speaker 1: as long as they can keep growing and molting and
Speaker 1: building a new shell, they'll just keep on going. They
Speaker 1: are such hardy creatures that scientists aren't even sure how
Speaker 1: old lobsters can get, and determining a lobster's age is
Speaker 1: difficult because they continue functioning as normal. Size isn't the
Speaker 1: best indicator either, because they can grow at different rates
Speaker 1: depending on their environment. If you dissect a lobster, you
Speaker 1: can look for calcified growth rings on their eyestalks and
Speaker 1: in their gastric mills, parts that never shed and do
Speaker 1: grow every year, similar to the growth rings in a tree.
Speaker 1: You can count these calcified rings to figure out a
Speaker 1: lobster's age, but obviously that's a little invasive, and generally speaking,
Speaker 1: you can figure that a cold water lobster will take
Speaker 1: about five to seven years and twenty to thirty molts
Speaker 1: to reach a pound in weight, which is about four
Speaker 1: hundred and fifty grams, which is about the minimum weight
Speaker 1: a lobster can be to be harvested in most fisheries.
Speaker 1: The largest lobster on record weighed about forty four pounds
Speaker 1: or twenty kilos. It was caught in nineteen eighty eight
Speaker 1: off the coast of Nova Scotia and was three and
Speaker 1: a half feet long that's a little over a meter.
Speaker 1: Scientists think it was at least one hundred years old.
Speaker 1: The studies have found that the average lobster is closer
Speaker 1: to half to a third of that though, which is
Speaker 1: really impressive, but it means that no. Lobsters are not immortal.
Speaker 1: Diseases do affect them. They might be caught and eaten
Speaker 1: by another animal, including a human. Also, molting takes a
Speaker 1: lot of energy, and it takes more energy the larger
Speaker 1: lobster gets, so sheer exhaustion can do a big lobster
Speaker 1: in when it outgrows its shell, even if it was
Speaker 1: bopping along like a whipper snapper up until then. For humans,
Speaker 1: decline is an accepted part of old age, even for
Speaker 1: those still searching for a fountain of youth. We expect
Speaker 1: the same in our pets and in the flies that
Speaker 1: buzz around us, albeit at different rates, but some animals
Speaker 1: are different. We've talked about this a bit before on
Speaker 1: the show. It has to do with senescence or planned
Speaker 1: cell death in humans and most other animals. Most of
Speaker 1: our cells have a limited life span, at the end
Speaker 1: of which the selling question will divide itself into two
Speaker 1: daughter cells, each containing a copy of the original cells DNA.
Speaker 1: Now DNA, you know, the code that tells our bodies
Speaker 1: how to function, is coiled up into structures called chromosomes,
Speaker 1: and chromosomes are on the ends with protective bits of
Speaker 1: otherwise useless DNA called telomeres. Every time a cell divides,
Speaker 1: those telomeres break off a little bit. They're protective because
Speaker 1: for as long as the telomeres are there, they prevent
Speaker 1: your working DNA from breaking off. When that happens, the
Speaker 1: cell will stop dividing and either destroy itself or become inactive.
Speaker 1: Telomeres protect your DNA like the little plastic caps on
Speaker 1: the end of a shoelace. The reason that we age
Speaker 1: is that eventually those telomere caps do break all the
Speaker 1: way off, and on a cellular level, our organs stop
Speaker 1: working as well, and we're less able to fight off
Speaker 1: illness and repair damage to our tissue. You know, we
Speaker 1: might get arthritis or cataracts or Parkinson's, and if we
Speaker 1: break a bone, it's much harder for us to recover.
Speaker 1: This doesn't happen in lobsters because they have an abundance
Speaker 1: an enzyme called telomerase. Telomerase works to add length to telomeres,
Speaker 1: thus extending cells lifespans. We humans do have telomerase in
Speaker 1: some specialized cells, like stem cells, which do specialized growth
Speaker 1: and repair work, but lobsters have them in most of
Speaker 1: their cells, which is why they can keep growing and
Speaker 1: repairing their whole bodies up to replacing missing limbs and
Speaker 1: not experiencing twilight years. They're not the only animals with
Speaker 1: quirky telomeres. Many types of turtles don't show compromised immunity
Speaker 1: or physical breakdown because of age. They also tend to
Speaker 1: become more fertile as they get older, and usually die
Speaker 1: because of predation or illness unrelated to age. There's a
Speaker 1: bird known as Leech's storm petrel that can sit in
Speaker 1: a human hand yet lives more than thirty years. Their
Speaker 1: telomeres grow longer with age. Unfortunately, we can't just turn
Speaker 1: on telmraase enzymes in humans to make us biologically immortal.
Speaker 1: That's because one of the times that we do see
Speaker 1: active telomerase throughout adult humans is in cancer. That's why
Speaker 1: cancerous cells don't die when they're supposed to and just
Speaker 1: keep replicating. There's a theory that in large, long lived
Speaker 1: species like humans, it's been evolutionarily advantageous to stop telomerase
Speaker 1: activity during adulthood in order to help prevent cancer. We
Speaker 1: still have a lot to learn about all of this.
Speaker 1: For example, we can take the interesting case of naked
Speaker 1: mole rats. These small rodents can live to about thirty
Speaker 1: five years old, whereas close relatives like guinea pigs, only
Speaker 1: live to about seven. Research has shown that naked mole
Speaker 1: rats do age, but they don't tend to die because
Speaker 1: of old age, and they seem to have evolved a
Speaker 1: non teleomere related way to fend off cancer. A lots
Speaker 1: more research is being conducted on many fronts. If one
Speaker 1: day we discover an important new treatment for cancer, it
Speaker 1: may be due to one of these creatures, or to
Speaker 1: a four hundred pound lobster eating its way around the
Speaker 1: North Atlantic. Today's episode is based on the articles ten
Speaker 1: Weird Facts about Lobsters by Shanna Friedman and is there
Speaker 1: a four hundred pound Lobster out There? By Jacob Silverman,
Speaker 1: both on How Stuffworks dot Com. Brain Stuff is production
Speaker 1: of iHeartRadio in partnership with hou stuffworks dot Com and
Speaker 1: is produced by Tyler Klang. Four more podcasts from my
Speaker 1: heart Radio. Visit the iHeartRadio app, Apple Podcasts, or wherever
Speaker 1: you listen to your favorite shows.