Eggs with legs experiment .

[Talkenlate04]

Very cool experiment.

Just curious, what do you use to keep track of data? A computer program/database or old fashioned pen and paper?

So far just an word document. I have 3rd grader hand writing so it's better that I use the computer.

 

[kyrga]

So far just an word document. I have 3rd grader hand writing so it's better that I use the computer.

I have some experience with computer programming, so if you end up needing something more organized, I could probably throw something together for you.

 

[DrAce]

Good set of observations, Talken. Now, again, if you wanted to be a stickler, then:
Get yourself a micrometer from the local hardware store. That way you can get a good record of how big they are. It may also be useful to consider marking them in some way. I'm thinking a tiny dab of paint with a toothpick, or something similar. Non-toxic, water-based paint to the TOP of their egg/abdomen should be fine.

I also think that weight should be a good measure. But because there isn't a way of identifying individuals yet, this is not feasible.

Again, I've got a good stats-program here, so I'm happy to help you crunch the numbers. PM me if you would like more science-experiment set-up advice (or you want to tell me to frig-off and leave you to your own devices!).

 

[Nerri1029]

going to add my two cents...

1 - I'm glad you did this, this hobby needs more of this kind of "investigating"

2 - the aphid bit - prekill some aphids and let them sit out. to observe the wtaer loss from the aphid bodies without a sling attached

3 - I'd use physical isolation as a way to keep track of them,
I think paint at any amount for an organism that young could prove detrimental,

- Some Key concepts for experiments:
- DO THE SAME THING(S) to all groups except that which you are looking for an effect from.
- stay away from assumptions.**
- keep detailed notes

GOOD LUCK

my gut reaction is that these guys are merely taking advantage of water sources ( papaer towel, aphid or sibling ) but that just my Hypothesis

 

[Talkenlate04]

my gut reaction is that these guys are merely taking advantage of water sources ( papaer towel, aphid or sibling ) but that just my Hypothesis

That's pretty much my hypothesis as well.

 

[DrAce]

It can't be that simple, though. Increasing the humidity should therefore decrease the response.

Also, if you're getting your water from a neighbouring spiderling, then you WILL be getting other nutrients as well. I doubt there is a water-filtering system which is removing protein, carbohydrate etc in the spiderling. They MUST be eating as well.

Also, if they are using the spiders/aphids for water, they must have a fairly well developed digestive system already. Water absorption is a function of a fairly well formed gut... I think.

 

[Talkenlate04]

I am watching for some of that as well but to start my tests are on a smaller scale to give me an idea of what to do when I make it on a larger scale.
Its going to get complicated.
Cause Ill have to have a group of like 50 in a higher humidity, and a group of 50 at lower. (control groups)
Then two more groups one high one low humidity that get offered water.(test group 1)And then two more groups high and low humidity, and get offered aphids.(Test group 2) And from all that I would then have to watch for faster or larger growth between all the groups to determine if one setting is more advantagous for the T then another when it comes to raising them in the early stages.
This could easily become a statistics nightmare. I do see why people shy away from this type of studying.

 

[DrAce]

Actually, I suspect you'd need more than a 'high' and 'low' humidity, if you are attempting to establish causality.

A 'high' and 'low' don't indicate what happens in the middle. If you really want to show that there is a relation between them, then several points on a x-axis are needed. The stats won't be too bad. I'm not a good statistian (is that a word?) but for your stuff you will need to do an 'Annova' (spelling questionable). There are statistics packages which will do this. Statistica is one, SigmaStat is another.

 

[cacoseraph]

I am watching for some of that as well but to start my tests are on a smaller scale to give me an idea of what to do when I make it on a larger scale.
Its going to get complicated.
Cause Ill have to have a group of like 50 in a higher humidity, and a group of 50 at lower. (control groups)
Then two more groups one high one low humidity that get offered water.(test group 1)And then two more groups high and low humidity, and get offered aphids.(Test group 2) And from all that I would then have to watch for faster or larger growth between all the groups to determine if one setting is more advantagous for the T then another when it comes to raising them in the early stages.
This could easily become a statistics nightmare. I do see why people shy away from this type of studying.

that's a bunch of experiments sort of rolled into one. for learning purposes it would probably be better to have a single indepenant variable. otherwise it is too hard to conclusively say that the independant variable has a direct causative relationship with the dependant variable

you could set up a couple concurrent experiments, if you wanted... but otherwise i would think having that many variables would possibly make all your hard work worth not as much as it could be

the stats won't be that hard. i would say excel should be capable of everything. might have to load the stats package, but maybe not. after all, what are you going to measure? maybe aggregate mass (unless you want to drop a few hundred bucks on a scale accurate to milligrams). maybe intermolt times.

i would suggest getting a decent hygrometer, too. so that would be another metric.

 

[Talkenlate04]

So what should I focus on then........ set some parameters for this. I am thinking to big maybe, so to make is simpler what should I try out with this batch?

Fed and none fed, watered and not watered? Dont worry about the humidity and temps just focus on that?
Oh and maybe noticable size differences when molts occur.

 

[DrAce]

You can't use 'noticable size differences' if you're not going to measure it. I don't see much alternative other than to measure their size accurately with a micrometer or something similar. I don't think these are particularly expensive, however. I'm going through my lab here to see if we have one I can 'slight-of-hand' lend you.

Also, I personally think that weight is going to be one of the best measures you have available for even the moisture question. You don't, however, need to do it individually. You could combine the spiderlings and get a total '50 spider' weight... and use it to get an average weight for the spiderlings. You will still need to get a good set of scales, probably accurate to about a hundredth of a gram.

I should also mention that you can do the 'fed, not fed, water, no water' at high and low humidity concurrently:
With a larger box, and four coffee-filter containers in two locations (high and low humidity) you could achieve this. You will need a lot of aphids, and a lot of patience, but it's do-able. Just have a set time at the day, and a set pattern of measuring. Say, 6pm... check the two boxes. Record temperature and humidity. Weigh control (not fed, not watered), weigh watered-not-fed, weigh watered-fed, weigh fed-not watered, record. Repeat in the lower humidity box.
9am... record humidity and temperature.

Record date after sac production of moult, record body length, and diameter of abdomen post moult.

You'd generate a lot of data, but it's just as hard to statistically lie about a big experiment as a small one.

 

[cacoseraph]

i think probably the first thing to think about is what your range of time you can spend on the experiment is

we could write up params for you that would have you measuring for 4 hours a day or 4 hours a week, depending on how far you are willing to go. but take this bit of advice from one bedroom experimenter (er, that sounds way more naughty than i meant) to another... it SUCKS to make a large time commitment... carry it out for a month or two... then get sick of it all and scale back. i would much rather plan slightly less ambitiously and stay the whole course, personally.

 

[Talkenlate04]

I was thinking just run this clutch on a small scale to give me a better hypothesis that I can then can test on with later sacs.
Say groups of 10........

I do have one question, where in the heck to I get a scale thats that accurate?

I cant just weigh groups ither because not all the nymphs in any group are eating or drinking.

 

[Varden]

You need a laboratory precision scale. There's several on ebay. I saw one that measured down to .002g for $25 and one that measured down to .001g for upwards of $989. Hopefully there's a happy medium.

Good work, by the way. I'm really interested in seeing what your results would be.

 

[davegrimm1]

ouch!

you guys are making my brains hurt.........

 

[cacoseraph]

lol, check out head shops.

though to get down to milligram accuracy is going to be pricey, unless you go used online like Varden was mentioning


if there is anyway you could do groups that is really the best. a group of ten gives you another order of magnitude of accuracy. kind of. er, let me think and remember.

 

[Talkenlate04]

My gf suggested the same thing, and Portland Oregon, well there is not much of a shortage of those places.