# Question about big crabs and lobsters **URL:** \ **Category:** Factual Questions\ **Created:** [June 30, 2014, 10:13pm UTC](https://boards.straightdope.com/t/question-about-big-crabs-and-lobsters/692038 "2014-06-30T22:13:56Z")\ **Posts on this page:** 20\ **Page:** 1
**Author:** ![gytalf2000](https://avatars.discourse-cdn.com/v4/letter/g/ac91a4/32.png) [@gytalf2000](https://boards.straightdope.com/u/gytalf2000)\ **Post date:** [June 30, 2014, 10:13pm UTC](https://boards.straightdope.com/t/question-about-big-crabs-and-lobsters/692038/1 "2014-06-30T22:13:56Z")
How big would a crab or lobster need to be in order to be a genuine threat to an adult human? Do they ever actually get that size? (I’m doubting it, but I’m willing to be educated otherwise…) ---
**Author:** ![dolphinboy](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dolphinboy/32/330_2.png) [@dolphinboy](https://boards.straightdope.com/u/dolphinboy)\ **Post date:** [June 30, 2014, 10:26pm UTC](https://boards.straightdope.com/t/question-about-big-crabs-and-lobsters/692038/2 "2014-06-30T22:26:17Z")
Crabs and Lobsters don’t attack people… even really big ones. While their claws can be quite powerful, I doubt they could sever a limb, even if they were inclined to do so. ---
**Author:** ![lissener](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/lissener/32/6139_2.png) [@lissener](https://boards.straightdope.com/u/lissener)\ **Post date:** [June 30, 2014, 10:42pm UTC](https://boards.straightdope.com/t/question-about-big-crabs-and-lobsters/692038/3 "2014-06-30T22:42:11Z")
Having an exoskeleton limits their size; why we don’t see giant tarantulas anywhere but Syfy. ---
**Author:** ![Fishtar](https://avatars.discourse-cdn.com/v4/letter/f/ed655f/32.png) [@Fishtar](https://boards.straightdope.com/u/Fishtar)\ **Post date:** [June 30, 2014, 11:10pm UTC](https://boards.straightdope.com/t/question-about-big-crabs-and-lobsters/692038/4 "2014-06-30T23:10:42Z")
> [@gytalf2000](#): > > How big would a crab or lobster need to be in order to be a genuine threat to an adult human? Do they ever actually get that size? (I’m doubting it, but I’m willing to be educated otherwise…) There is speculation Amelia Earhart and Fred Noonan were eaten alive by cocoanut crabs. [http://creepyanimals.com/wordpress/wp-content/uploads/2010/02/coconut-crab.jpg](http://creepyanimals.com/wordpress/wp-content/uploads/2010/02/coconut-crab.jpg) If so, they were dying anyway and could not fend for themselves properly. But the crabs are certainly big enough to be considered “a threat”, if not a real serious one. Imagine waking up with one of those things clamped to your nose… ---
**Author:** ![bob\_2](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/bob_2/32/3341_2.png) [@bob\_2](https://boards.straightdope.com/u/bob_2)\ **Post date:** [June 30, 2014, 11:13pm UTC](https://boards.straightdope.com/t/question-about-big-crabs-and-lobsters/692038/5 "2014-06-30T23:13:56Z")
And of course there are Stephen King’s ‘lobstrosities’. “Dad-a-chum? Dum-a-chum? Ded-a-chek? Did-a-chick?” ---
**Author:** ![Yllaria](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/yllaria/32/3452_2.png) [@Yllaria](https://boards.straightdope.com/u/Yllaria)\ **Post date:** [June 30, 2014, 11:16pm UTC](https://boards.straightdope.com/t/question-about-big-crabs-and-lobsters/692038/6 "2014-06-30T23:16:52Z")
> [@gytalf2000](#): > > How big would a crab or lobster need to be in order to be a genuine threat to an adult human? . . . Depends. Are you a guy? Are you skinny dipping? ---
**Author:** ![Gatopescado](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/gatopescado/32/5711_2.png) [@Gatopescado](https://boards.straightdope.com/u/Gatopescado)\ **Post date:** [July 1, 2014, 5:29am UTC](https://boards.straightdope.com/t/question-about-big-crabs-and-lobsters/692038/7 "2014-07-01T05:29:44Z")
According to Steven Adler of _Guns N Roses,_ the crabs don’t need to be very big at all. ---
**Author:** ![Little\_Nemo](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/little_nemo/32/3120_2.png) [@Little\_Nemo](https://boards.straightdope.com/u/Little_Nemo)\ **Post date:** [July 1, 2014, 5:49am UTC](https://boards.straightdope.com/t/question-about-big-crabs-and-lobsters/692038/8 "2014-07-01T05:49:17Z")
> [@lissener](#): > > Having an exoskeleton limits their size; why we don’t see giant tarantulas anywhere but Syfy. How big are we talking? This [crab](http://www.visitsealife.com/SiteImages/Assets/6/1/BigDaddyandChrisBrown.jpg) isn’t going to menace Tokyo but he’s bigger than any tarantula. ---
**Author:** ![sich\_hinaufwinden](https://avatars.discourse-cdn.com/v4/letter/s/c5a1d2/32.png) [@sich\_hinaufwinden](https://boards.straightdope.com/u/sich_hinaufwinden)\ **Post date:** [July 1, 2014, 6:07am UTC](https://boards.straightdope.com/t/question-about-big-crabs-and-lobsters/692038/9 "2014-07-01T06:07:38Z")
> [@Little\_Nemo](#): > > How big are we talking? This [crab](http://www.visitsealife.com/SiteImages/Assets/6/1/BigDaddyandChrisBrown.jpg) isn’t going to menace Tokyo but he’s bigger than any tarantula. Wow. I’ve seen the pic of the coconut crab before but not what you posted. Someone start melting a bucket of butter! ---
**Author:** ![njtt](https://avatars.discourse-cdn.com/v4/letter/n/ecd19e/32.png) [@njtt](https://boards.straightdope.com/u/njtt)\ **Post date:** [July 1, 2014, 8:05am UTC](https://boards.straightdope.com/t/question-about-big-crabs-and-lobsters/692038/10 "2014-07-01T08:05:34Z")
> [@dolphinboy](#): > > Crabs and Lobsters don’t attack people… even really big ones. When I was a boy, and used to play at the seaside, I got painfully pinched by crabs many times (and no, I wasn’t trying to torture them or anything). Of course, they were only little ones, and couldn’t harm me much. ---
**Author:** ![Robot\_Arm](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/robot_arm/32/18280_2.png) [@Robot\_Arm](https://boards.straightdope.com/u/Robot_Arm)\ **Post date:** [July 1, 2014, 8:40am UTC](https://boards.straightdope.com/t/question-about-big-crabs-and-lobsters/692038/11 "2014-07-01T08:40:54Z")
> [@Fishtar](#): > > There is speculation Amelia Earhart and Fred Noonan were eaten alive by cocoanut crabs. > [http://creepyanimals.com/wordpress/wp-content/uploads/2010/02/coconut-crab.jpg](http://creepyanimals.com/wordpress/wp-content/uploads/2010/02/coconut-crab.jpg) > > If so, they were dying anyway and could not fend for themselves properly. But the crabs are certainly big enough to be considered “a threat”, if not a real serious one. Imagine waking up with one of those things clamped to your nose… Ewww, those things give me the willies. If Earhart and Noonan were on land somewhere to be eaten by coconut crabs, couldn’t they have gotten some sustenance by eating the crabs? Fresh water may have been a bigger problem than food, but it seems odd to be eaten by something that would normally be your dinner. ---
**Author:** ![Fishtar](https://avatars.discourse-cdn.com/v4/letter/f/ed655f/32.png) [@Fishtar](https://boards.straightdope.com/u/Fishtar)\ **Post date:** [July 1, 2014, 9:18am UTC](https://boards.straightdope.com/t/question-about-big-crabs-and-lobsters/692038/12 "2014-07-01T09:18:06Z")
> [@Robot\_Arm](#): > > Ewww, those things give me the willies. > > If Earhart and Noonan were on land somewhere to be eaten by coconut crabs, couldn’t they have gotten some sustenance by eating the crabs? Fresh water may have been a bigger problem than food, but it seems odd to be eaten by something that would normally be your dinner. If they did end up on Gardner Island, I am sure crabs were initially on the menu. But then dehydration set in, and the situation was reversed. The lovely web of life… ---
**Author:** ![Kobal2](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/kobal2/32/20_2.png) [@Kobal2](https://boards.straightdope.com/u/Kobal2)\ **Post date:** [July 1, 2014, 9:49am UTC](https://boards.straightdope.com/t/question-about-big-crabs-and-lobsters/692038/13 "2014-07-01T09:49:16Z")
> [@Robot\_Arm](#): > > Ewww, those things give me the willies. If it helps, you could probably outrun them on a pair of broken legs. They’re not exactly cheetahs. ---
**Author:** ![marshmallow](https://avatars.discourse-cdn.com/v4/letter/m/df705f/32.png) [@marshmallow](https://boards.straightdope.com/u/marshmallow)\ **Post date:** [July 1, 2014, 10:17am UTC](https://boards.straightdope.com/t/question-about-big-crabs-and-lobsters/692038/14 "2014-07-01T10:17:08Z")
In the distant past arthropods could be much larger. I don’t know if any of the giant water scorpions could have killed a human or would be inclined to do so, but they’d definitely be high grade nightmare fuel. Do a Google image search for Eurypterids if you don’t feel like sleeping. Jaekelopterus was estimated to be 2.5 meters long. :eek: ---
**Author:** ![Robot\_Arm](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/robot_arm/32/18280_2.png) [@Robot\_Arm](https://boards.straightdope.com/u/Robot_Arm)\ **Post date:** [July 1, 2014, 10:28am UTC](https://boards.straightdope.com/t/question-about-big-crabs-and-lobsters/692038/15 "2014-07-01T10:28:32Z")
> [@Kobal2](#): > > If it helps, you could probably outrun them on a pair of broken legs. They’re not exactly cheetahs. Well, they’re in the South Pacific somewhere, and I’m in Boston, and they still give me the willies, so outrunning them is not really a great comfort. ---
**Author:** ![Mijin](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mijin/32/9369_2.png) [@Mijin](https://boards.straightdope.com/u/Mijin)\ **Post date:** [July 1, 2014, 10:36am UTC](https://boards.straightdope.com/t/question-about-big-crabs-and-lobsters/692038/16 "2014-07-01T10:36:55Z")
> [@Kobal2](#): > > If it helps, you could probably outrun them on a pair of broken legs. They’re not exactly cheetahs. Similarly, if it helps, they’re called coconut crabs because they can climb trees to fetch coconuts. They’re also called “robber crabs” because they’re known to climb through people’s open windows, and take objects from inside. So, if you lived on an island with these, it’s entirely possible you are woken in the night by a coconut crab that’s crawled into your home and on to your bed. Wait…that probably doesn’t help at all. ---
**Author:** ![kayaker](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/kayaker/32/441_2.png) [@kayaker](https://boards.straightdope.com/u/kayaker)\ **Post date:** [July 1, 2014, 10:57am UTC](https://boards.straightdope.com/t/question-about-big-crabs-and-lobsters/692038/17 "2014-07-01T10:57:27Z")
In my youth I cooked in an upscale seafood restaurant. Our lobsters came 25 (IIRC) to a styrofoam bin. The invertebrates had their claws banded with rubber bands. But in every box, there’d be one claw missing its band, and things were too rushed to be cautious. Ouch. ---
**Author:** ![Lukeinva](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/lukeinva/32/17872_2.png) [@Lukeinva](https://boards.straightdope.com/u/Lukeinva)\ **Post date:** [July 1, 2014, 11:32am UTC](https://boards.straightdope.com/t/question-about-big-crabs-and-lobsters/692038/18 "2014-07-01T11:32:31Z")
About six feet, as a guess. ---
**Author:** ![Machine\_Elf](https://avatars.discourse-cdn.com/v4/letter/m/82dd89/32.png) [@Machine\_Elf](https://boards.straightdope.com/u/Machine_Elf)\ **Post date:** [July 1, 2014, 12:09pm UTC](https://boards.straightdope.com/t/question-about-big-crabs-and-lobsters/692038/19 "2014-07-01T12:09:03Z")
A couple of years ago [a 27-pound lobster was caught.](http://blogs.discovery.com/animal_news/2012/02/largest-lobster-ever-caught-in-maine-has-claws-that-can-break-your-arm-1.html) It’s believed that its claws could break a man’s arm. And that’s not even the biggest one ever caught; according to the article, that title goes to a 44-pounder caught back in 1977. ---
**Author:** ![gytalf2000](https://avatars.discourse-cdn.com/v4/letter/g/ac91a4/32.png) [@gytalf2000](https://boards.straightdope.com/u/gytalf2000)\ **Post date:** [July 1, 2014, 3:46pm UTC](https://boards.straightdope.com/t/question-about-big-crabs-and-lobsters/692038/20 "2014-07-01T15:46:12Z")
Thanks for the replies. Sometimes I enjoy thinking abut creatures that have us on the menu, and then the other day, crabs were on my mind, so I decided to post the question. I always enjoy getting educated by the fun folks on the SDMB! [Next page](https://boards.straightdope.com/t/question-about-big-crabs-and-lobsters/692038.md?page=2)