After noticing that there has been some confusion about the terms describing crabs as "large" or "small" etc. And the haphazard use of comparison to everyday objects, I think its time that we as a community agreed on a standard scale as to how to describe our crabs sizes. I propose that instead of using the comparison measurement, because the various types of shells used can have an effect as to what there overall size is and thus what object they are compared to, That we use a measuremnt of the roundest part of the shell opening as our description as to how big the crabs are. I suggest shell opening, because it gives a better idea of how big the actual crabs body is, and not just its shell. below are my suggestions for measurement and labels, please feel free to sugest alterations.
Teenie: Under .5"
Small: .5" - 1"
medium: 1" - 1.5"
Large: 1.5" - 2.5"
Jumbo: 2.5"+
Standardization of crab size measurement
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Guest
Topic author
Measurement
I understand your problem you have noted. And Im sure that there are many people out there who have crabs that are in shells that are either too big or too small. I considered the measurement of the BP, but I figured this might be difficult. This is one of the resons that I made the measurement listing overlapping. I forgot, though, to include metric measurements for our international members, those are listed below.
Teenie: Under .5"; 1.27cm
Small: .5" - 1"; 1.27 - 2.54cm
medium: 1" - 1.5"; 2.54 - 3.81cm
Large: 1.5" - 2.5"; 3.81 - 6.35cm
Jumbo: 2.5"+; 6.35cm +
Teenie: Under .5"; 1.27cm
Small: .5" - 1"; 1.27 - 2.54cm
medium: 1" - 1.5"; 2.54 - 3.81cm
Large: 1.5" - 2.5"; 3.81 - 6.35cm
Jumbo: 2.5"+; 6.35cm +
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Guest
Topic author
I don't know...the current algorithm we use is inaccurate and unreliable, in my opinion.
I'm thinking a better way to classify crabs is by their weight...but of course, the weight of the shell gets in the way, making it harder. Still, if we could weigh the crabs with shells and subtract the weight of the shell (best if known, but estimated if necessary), and then compare their weight with a pre-set scale, wouldn't it be more effective and accurate? Another way is to find the general percentage of the weight the crabs themselves compose. Or if the percentage of the shell weight was sufficiently negligible, I suppose we can just ignore it...
I'm thinking a better way to classify crabs is by their weight...but of course, the weight of the shell gets in the way, making it harder. Still, if we could weigh the crabs with shells and subtract the weight of the shell (best if known, but estimated if necessary), and then compare their weight with a pre-set scale, wouldn't it be more effective and accurate? Another way is to find the general percentage of the weight the crabs themselves compose. Or if the percentage of the shell weight was sufficiently negligible, I suppose we can just ignore it...
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Guest
Topic author
Weight
I agree, Co'yrtesia, that weight would be the best way to describe a crabs size, unfortunatly, as you pointed out, the shell weight would get in the way, the other problem I see is that although it is reliable, it isnt very practicle. I doubt that everyone has a scale sensative enough to give an accurate measurement of our lil guys weights. Good idea though.
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Guest
Topic author
I think the reason we have been using other objects (such as quarter and golf ball) to describe our crabs is because it's simple. Any new crab owner can give an estimation about their crab’s size when comparing it to a quarter or softball. No measurement converting required. The fact that our little guys live in shells makes this fairly impossible to do with any real accuracy. We use the object terms because everyone knows them. I agree that we, as a crabbing community, should decide a definitive way to measure size, but because of the shell, it's still just an estimation. I'm afraid that the object comparison is too useful to go away. "He's as big as a ping pong ball" is much easier for a new crabber to describe than, "The shell opening is 1.25" from left to right." I think the present descriptions are "user friendly," which is why we use them.
As stated, the shell opening has many variables; I have crabs that wear too small shells and some that choose ones way too large. Also, the type of shell would come into play when measuring. There are many different types and shapes of openings for crabs to choose from, so that makes it really hard. When measuring a shark eye, would it be the same as a turbo? And if so, would that really tell more about the size of the crab?
I'm not trying to argue, I do think we should decide on this, but I think that descriptive methods will always work best for most crabbers.
*Edit*
Also, the reason we need to know what size a crab is generally has regards to how much room they need. If this is the case, shouldn't we be concerned with how much room is taken up by the crab, which would involve some sort of "spherical" description? Also, when a new crabber is describing how large or small their crabs are, I have a much easier time visualizing a ping pong ball in a 10G tank than a hermie that has a shell opening of 1.25". My point is, the less complicated, the better. Whatever system is decided on, it should be simple enough for anyone to decipher.
As stated, the shell opening has many variables; I have crabs that wear too small shells and some that choose ones way too large. Also, the type of shell would come into play when measuring. There are many different types and shapes of openings for crabs to choose from, so that makes it really hard. When measuring a shark eye, would it be the same as a turbo? And if so, would that really tell more about the size of the crab?
I'm not trying to argue, I do think we should decide on this, but I think that descriptive methods will always work best for most crabbers.
*Edit*
Also, the reason we need to know what size a crab is generally has regards to how much room they need. If this is the case, shouldn't we be concerned with how much room is taken up by the crab, which would involve some sort of "spherical" description? Also, when a new crabber is describing how large or small their crabs are, I have a much easier time visualizing a ping pong ball in a 10G tank than a hermie that has a shell opening of 1.25". My point is, the less complicated, the better. Whatever system is decided on, it should be simple enough for anyone to decipher.
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Guest
Topic author
clarification
You make a good point, that the everyday object comparison is very user friendly. Maybe I didnt make it clear that the proposed system isnt supposed to be exact, to allow for instances where the shell isnt a perfect fit, again, reason for overlapping measurements. I also figured that if someones shell was right on, about say 1", but the crab was to big for the shell, it would be obviously a medium crab. Also, im not sure if I said it or not, but the measuring was supposed to take place at the roundest part of the shell, to account for the oval shaped etc. As this is most likely where the crab will be fitting.
Also, I understand that the most commpn place to find the need for an idea of crab size would be to figure out how many would fit in a tank. Thats why I think that we should establish a minnimum gallon requirement for each crab size. as such:
Teenie: .5 gallons
Small: 1 gallons
Medium: 2 gallons
Large: 3 gallons
Jumbo: 5 gallons
Im hoping that this will all be accepted to help both current discussions, and to eliminate some of the guesswork and estimation for new crabbers. My hope out of all of this is just to standardize some of the grey areas in crab care, so that we can help improve the care of our crabs.
Also, I understand that the most commpn place to find the need for an idea of crab size would be to figure out how many would fit in a tank. Thats why I think that we should establish a minnimum gallon requirement for each crab size. as such:
Teenie: .5 gallons
Small: 1 gallons
Medium: 2 gallons
Large: 3 gallons
Jumbo: 5 gallons
Im hoping that this will all be accepted to help both current discussions, and to eliminate some of the guesswork and estimation for new crabbers. My hope out of all of this is just to standardize some of the grey areas in crab care, so that we can help improve the care of our crabs.
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Guest
Topic author
I find the method of using familiar objects to be the easiest.
If you tell me your crab is 7 ounces I wouldn't have any idea what size that equates too.
Measuring shells doesn't work well either because I have crabs that choose shells that are huge and we all know E's love shells that are too small.
We've had this discussion before on here and never really got too far other than to sort out what we recognize as the sizes for each category. We have some people calling large crabs jumbos, when they really aren't.
If you tell me your crab is 7 ounces I wouldn't have any idea what size that equates too.
Measuring shells doesn't work well either because I have crabs that choose shells that are huge and we all know E's love shells that are too small.
We've had this discussion before on here and never really got too far other than to sort out what we recognize as the sizes for each category. We have some people calling large crabs jumbos, when they really aren't.
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Guest
Topic author
Well, relating it to a familiar object has its downsides too, I noticed. Should the crab alone or the crab in a shell be compared to something else?
Example: Kasparov was a PP that probably qualifies as "Large crab". Looking at her turbo shell vertically, the radius of it from the most outer point to the center is 37mm. The widest length of the shell's opening is 33mm. With Kasparov and the shell together, her size was between a ping pong ball and a tennis ball. However, when she got into a shellfight and went naked, I noticed how small she looked. Curled up, she looked like she could barely fit into a ping-pong ball...
When I posted about her condition here several months ago, I didn't know whether she was 'ping-pong ball sized' or 'between ping pong and tennis ball sized'.
So, when we make a reference, do we estimate their size with a shell or without a shell? Neither is convinient, which is why I thought the weight will be the best way to get the idea of the size of the crab. If we had a scale like <5g: tiny, 5-10g: small, 10-20g; medium, and so on, I thought it will be more reasonable of a scale.
Another method is to take a picture of each crab with a coin or a ball next to it, as a reference.
Example: Kasparov was a PP that probably qualifies as "Large crab". Looking at her turbo shell vertically, the radius of it from the most outer point to the center is 37mm. The widest length of the shell's opening is 33mm. With Kasparov and the shell together, her size was between a ping pong ball and a tennis ball. However, when she got into a shellfight and went naked, I noticed how small she looked. Curled up, she looked like she could barely fit into a ping-pong ball...
When I posted about her condition here several months ago, I didn't know whether she was 'ping-pong ball sized' or 'between ping pong and tennis ball sized'.
So, when we make a reference, do we estimate their size with a shell or without a shell? Neither is convinient, which is why I thought the weight will be the best way to get the idea of the size of the crab. If we had a scale like <5g: tiny, 5-10g: small, 10-20g; medium, and so on, I thought it will be more reasonable of a scale.
Another method is to take a picture of each crab with a coin or a ball next to it, as a reference.
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Guest
Topic author
Well, we have to include the shell in our measurement; to do otherwise is unpractical and not very useful as all hermit crabs are in shells. I propose that we measure hermit crab size by the area the crab takes up when out and walking around. This is the size we are concerned with. If the crab is in the shell, we are just measuring the shell. From overhead, when the crab is walking around, there will be a spherical measure that could easily be compared with some form of ball or coin.
Here is a poorly drawn example of an overhead shot of a crab. The blue circle is the measurement. That area could then be compare to any spherical object for an easy description. I don't think we can totally redo how we describe our crabs, but I think a uniform way of measuring, like this, is more of what we are aiming for. Any thoughts?
Here is a poorly drawn example of an overhead shot of a crab. The blue circle is the measurement. That area could then be compare to any spherical object for an easy description. I don't think we can totally redo how we describe our crabs, but I think a uniform way of measuring, like this, is more of what we are aiming for. Any thoughts?
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Guest
Topic author
I like Crabaddict's suggestion better. It makes more sense to judge size based on a fully-splayed diameter. That makes it a lot easier to judge how much space the crab actually needs. As we all know, teenies don't need as much space as larger crabs do. Is it possible for hermies to grow bigger than a softball? Probably a dumb question, but I really don't know.
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Guest
Topic author
I think that crabbaddicts way is good to find out how much room a hermie needs in gallon
ex:A hermie with a 5 inch diameter needs 4 gallons......
Also, an iconvinient but interesting way to find the size of a hermie is by using water displacement to find the volume, but air pockets in the shells and shell sizes would obstruct the measurement
Just a thought
ex:A hermie with a 5 inch diameter needs 4 gallons......
Also, an iconvinient but interesting way to find the size of a hermie is by using water displacement to find the volume, but air pockets in the shells and shell sizes would obstruct the measurement
Just a thought -
Guest
Topic author
I have a hard time with the BP thing because it doesn't help me tell someone how many crabs they can have in a 10G. For instance: "My largest crab has a BP of 1.25 inches long. My meduim crab has a BP of 1 inch, and my small crabs, etc. etc." This doesn't really help me answer a size and space question. I think the area of the shell and crab should be measured, as I proposed on the previous page.
Also, new members with new crabs should let their crabs get used to everything and destress. But, in order to answer a space question for a new owner, we would have to ask them to measure the crab's BP? I just don't think that it's practical.
NOTE: It would be more productive if members read through the thread before posting more on this issue. Many of the topics have been discussed, but all we are doing is going in circles. I think we couldactually come to an agreement on this if we consider how we are going to use the information. Measuring BP's and space ratios is all well and fine for experienced crabbers, but the new owners would benefit most from a definitive crab measure, so I do think we should be catering to them.
*edit* Also, for a "BP by species" method to work, we would have to ID the new owners species before even beginning to answer a size and space question. IDing is sometimes difficult enough, but I think we are asking too much of new crabbers here.
Thanks for reading!
Also, new members with new crabs should let their crabs get used to everything and destress. But, in order to answer a space question for a new owner, we would have to ask them to measure the crab's BP? I just don't think that it's practical.
NOTE: It would be more productive if members read through the thread before posting more on this issue. Many of the topics have been discussed, but all we are doing is going in circles. I think we couldactually come to an agreement on this if we consider how we are going to use the information. Measuring BP's and space ratios is all well and fine for experienced crabbers, but the new owners would benefit most from a definitive crab measure, so I do think we should be catering to them.
*edit* Also, for a "BP by species" method to work, we would have to ID the new owners species before even beginning to answer a size and space question. IDing is sometimes difficult enough, but I think we are asking too much of new crabbers here.
Thanks for reading!
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Guest
Topic author
I undrstand what Crabaddict is saying, in that someone talking about a crab with a BP of 1.5" or whatever doesnt really help us in getting an idea of overall crab size until we each as individuals get to know the ratios between overall crab size and BP size. Thats why I suggested having labels for sizes, so instead of talking about BP size, they can say that they have a medium crab, and we all get an idea of about where that crab falls in the size range. I also dont think that when measuring your crab, however we decide to do this, that you are exact in your measurements, say to the sixteenth of an in, or to the millimter, but instead get a good estimation to fit your crab into one of the size categories.
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Guest
Topic author
I totally agree that labels, such as: "large," "jumbo," and "small," would be the end result. However, in order for a new owner to say "medium" or "small," they would still have to measure the BP to obtain the label. The "surface area" thing I proposed is this easy for me to ask a new crab owner: "About how much space does he take up when he's out walking around? About a golfball or so?" From their answer, I can gauge the crab's size very quickly and easily, without a lot of guesswork.
There is just as much estimation at work in this example as with every other measurement method proposed. The difference is: this one is easy!
Applying the labels is no problem, it's deciding an easy and "user friendly" way of measuring for new and experienced crab owners that is our dillema. Without the measuring, we have no labels.
I am curious if anyone sees a real problem with the "surface area" method I'm proposing. There is no more estimation here than any other method discussed. I'm just curious what exactly anyone sees as a drawback. Meaning: Why would the BP method be better and /or more accurate and useful?
Comments?
There is just as much estimation at work in this example as with every other measurement method proposed. The difference is: this one is easy!
Applying the labels is no problem, it's deciding an easy and "user friendly" way of measuring for new and experienced crab owners that is our dillema. Without the measuring, we have no labels.
I am curious if anyone sees a real problem with the "surface area" method I'm proposing. There is no more estimation here than any other method discussed. I'm just curious what exactly anyone sees as a drawback. Meaning: Why would the BP method be better and /or more accurate and useful?
Comments?
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Guest
Topic author
The only real differance I see between the two is how the masurement is obtained. I agree that your method gives a better overall idea if the sixw of the crab, but I must also say, that for a beginner to try to measure the walking leg span of a crab, might actually be difficult, thus why I would prefer shell opening or BP measurement, because, as I see it, this measurement is much easier to obtain, especially by a new crab owner. I know when I was starting out, it wasnt too hard to pick up a crab, and measure their shell opening or BP, as it took them a while to become active and "warm up" to me, and provide a situation where I could measure leg span. Again, I see the legspan Idea as a beter overall idea of measurement, but not as practical or easily obtained.