Captive -vs- Free

[jday]

Hi, folks. In my limited experience (two years), it seems that the free-range adult Chinese mantises I catch in the yard are significantly larger than our "pet" adult mantises...about 20% larger. We feed our mantises daily, and give 'em a varied diet of wild-caught bugs, but we do keep 'em confined. I'm wondering if captive-bred and captive-raised mantises are generally smaller than their wild counterparts, or if I'm somehow doing a crappier job than I realized. Any thoughts?

 

[lunarstorm]

Interesting question. As I've never lived in an area where wild, free-range mantids could be found, I can't compare. But I am guessing that mantids in captivity have a longer average lifespan and I'd be surprised if the average size of wild vs. bred indoors was proven to be different (I'd expect their size to be mostly a factor of genetics and diet)? Regarding diet, there are two extra optional steps that I hope my mantids will benefit from. I dunno how much of a difference it will make in the long run but I figured it can't hurt.

1) Feed the feeders. My houseflies and bluebottles usually get a day or two to eat some food and drink water before meeting a mantis. I am using the fly food from mantispets.com.

2) Dust the feeders with a mixture of bee pollen and honey. I'll use "Yen's Blend", I just ordered some from mantisplace.com.

I'll have to get a few Chinese ooths sometime and see how it goes. Maybe keep track of the sizes (min, max, avg) and see how that compares to the wild caught that the rest of you get to enjoy.

 

[mantisboy]

All of my Euro Mantids are caught in the wild (my yard) and they all range in 2 sizes, small and large. The smaller females are 2.5 inches, the larger females are 3.5 inches. It appears that there are normal sized ones.......and what I call runts. This is true with Males as well.

The size of their Coxae can also vary between Mantids of the same size. However overall body length, leg lengths, size of the head, and antennae lengths seem to be about the same.

 

[patrickfraser]

Mantids may be similar to goldfish and will grow larger based on the living area. Maybe???

 

[Ntsees]

Mantids may be similar to goldfish and will grow larger based on the living area. Maybe???

My current mantids are no bigger nor smaller than the wild ones and they were raised in small containers. The smaller ones were only small because I didn't get to feed them as much as I should have. But there are many factors that affect the size. I've only found that more space just makes them more healthier because they get to exercise a bit but it doesn't necessarily allow them to grow larger.

 

[ems08d]

I have been learning in my Biology class about how the environment can influence gene expression. It's called phenotypic plasticity or polyphenism. For example a snail will have a different shell shape if it is raised with a sunfish predator versus if it is raised with a crayfish predator based on which shape is best for protecting it. I think that the size of your wild-caught mantids versus your captive ones probably has more to do with that than with the size of their home or their diet.

 

[PhilinYuma]

I have been learning in my Biology class about how the environment can influence gene expression. It's called phenotypic plasticity or polyphenism. For example a snail will have a different shell shape if it is raised with a sunfish predator versus if it is raised with a crayfish predator based on which shape is best for protecting it. I think that the size of your wild-caught mantids versus your captive ones probably has more to do with that than with the size of their home or their diet.

This is very interesting. It appears to conflict with two old genetic axioms that I learned in school, but my knowledge of genetics is very rusty indeed, so I shall be happy to learn.

First, it is my belief that most organisms exhibiting this trait are plants, like yourself, or sessile or sluggish animals like many molluscs. This plasticity serves as a defense when physical distancing is not an option.

Another dictum is that when a physical trait, like size within given parameters, can be controlled by the environment, then it cannot be regarded as phenotypical. This issue came up on this forum a few years back when we were discussing possible causes for mantids eclosing with crumpled wings and would certainly seem to apply here. I think that there was a time when Allen's rule was thought to be pheotypical, but I understand that more rapid cartilage growth at higher temperatures is now being offered as at least a possible explanation for the phenomenon that it describes..

If you are any of our other young biologists can expand on this, I should be most grateful.

Addendum: Well, for a moment, I forgot that Google is my friend. I found the article that yr teacher cited, and I also found an example of plasticity in the gray treefrog tadpole ( http://www.jstor.org/pss/2410833 ) which is certainly not cessile. In every case, though, polyphenism seems to constiture a passive defense, and I am not sure how a greater size in captive mantids (the wild form has to be the original phenotype, surely) would help their survival. Am I missing something?

 

[meaganelise9]

I have been learning in my Biology class about how the environment can influence gene expression. It's called phenotypic plasticity or polyphenism. For example a snail will have a different shell shape if it is raised with a sunfish predator versus if it is raised with a crayfish predator based on which shape is best for protecting it. I think that the size of your wild-caught mantids versus your captive ones probably has more to do with that than with the size of their home or their diet.

Whoa. Interesting. Also, wouldn't the environment affect their growth rate? I've read that if you don't give some mantids a cooler temperature at night, it speeds their metabolism and causes them to grow more quickly, which, i would think. would possibly shorten their lives and give them less time to grow as big as they would otherwise.