52: Long Lives of Lobsters
The internet claims lobsters are immortal. Amy pulls a Dana Scully and debunks the heck out of that idea.
Long Lives of Lobsters Transcript:
Welcome to Brain Junk, I’m Trace Kerr.
And I’m Amy Barton, and this is a Brain Storm! I have good news, and bad news: Lobsters are not immortal.
AB: I didn’t realize, until recently, that was a hypothesized thing, they do not live forever.
TK: OK. (laughs)
AB: So backtracking to why there was this thought. Apparently all growing living things have what scientists call senescence, and that is the process of deteriorating with age. Loss of a cell’s power of division and growth.
AB: That’s not an observed thing in lobsters, basically. They keep growing and growing and growing, they shed their skin, and then they grow some more. Then the internet says “They’re immortal! They live forever!”
TK: Well, and there was probably some thought, I mean even back in the day-you see this lobster, and it sheds it’s shell, then it’s soft and it gets a new shell and they just keep getting bigger and bigger. It would be easy to guess that hey, where’s the limit? It just keeps going.
AB: Yes. And they keep pulling giant lobsters out of the deep, deep ocean, and so you see these huge creatures and think “Wow!”. And so it is true, lobsters keeping eating , growing and reproducing right up until the end of life, like most decapod crustaceans, that’s also crayfish and shrimp, they have intermediate growth. That means they don’t reach a set size limit in their lifetime and they continue to grow til they die, or, they actually are more often killed than die of natural causes.
TK: Yeah, I was going to say they continue growing until they end up on someone’s dinner plate probably.
AB: Mmmhmmm, yeah. That is often the case.According to Carl Wilson, he is the Lead Lobster Biologist, I just want to say that again. “Hi, I’m Carl Wilson, the Lead Lobster Biologist with the Maine Department of Marine Resources.” He probably doesn’t sound like that.
TK: Probably not at all.
AB: If that were me I’d be “Hi! I’m Amy Barton, the Lead Lobster Lady. I’m a biologist.” I would totally lead with that title.
TK: I would too.
AB: He says between ten and fifteen percent of lobsters die naturally.
TK: Wow! That’s low. How long is a lobster life?
AB: Mmmmmmm…..I didn’t do that science. Could be years and years.
TK: Let’s find out, cause that’s something I think I want to know.
AB:But they do, initially as they’re young lobsters, they do molt and regrow their shells many times in their early life as they are getting up to adult size. And then it’s more of an annual process. How many annual processes is it, Trace?
TK: Well, it says that they can grow up to four feet long and weigh as much as forty pounds AND it is believed lobsters can live as long as 100 years.
AB:So they’re roughly the size of a second grader at death.
TK: Oh god!
AB: Can you imagine?!
TK: That’s a sentence I never thought I’d hear someone say.
AB: I like to give some context, folks. Some third graders. Now I’m, going to look at them all differently when they’re walking down the halls. They eventually stop shedding their exoskeletons.Basically, it does eventually slow down, but they just run out of the metabolic oomph to complete that molting process because it’s hard. 85% of them either die during that molting process because they are vulnerable or they just can no longer, that one last time, they can’t do that >grunts< to get that shell to pop off, so they are trapped.
AB: I know. But they could be dying of disease, but they’re just dying in their shell. I really know how to brighten things up here.
TK: Boy you really know how to end an episode.
AB: Yeah. So good. So lobsters all die everybody… Mmmmhmmmm…. Yeah.
TK: Want to hear more, we’re on… you probably don’t…
AB: I HAVE more! No, I have more actually, I’m just reviewing my notes.
TK: Oh, ok.
AB: How old lobsters are. It is difficult-It’s not like trees. They molt their shell, and so there’s not this build up of years of “We can see by the ring on the trees how old they are.” so they could be much older. You could find a really old lobster and not know it! So they’re still an exciting mystery. Let’s end with the exciting mystery of lobster age.
TK: Oooh, I like it! And THAT is a Brain Storm. Want to hear more, we’re on Facebook and Instagram as @BrainJunkPodcast. And you can find us on Twitter as @MyBrainJunk. Amy and I will catch you next time with more of everything you never knew you wanted to know, and I guarantee you will not be bored.