What's the difference?

[Johanna Turner]

Can someone please explain to me how you differentiate between the following:

Nymph
Spiderling
Juvenile
Sub Adult
Adult

It's been bugging me how I would classify mine as they grow.

Any info appreciated!

[rhys brigida]

Can someone please explain to me how you differentiate between the following:

Nymph
Spiderling
Juvenile
Sub Adult
Adult

It's been bugging me how I would classify mine as they grow.

Any info appreciated!

Johanna,
Here's an explanation of some terms: http://atshq.org/Development.pdf These are generally useful. Spiderling and juvenile can be interchangeable with young, immature (numbered by instar). Nymph can be postembryo.

I hope the article is helpful.

Rhys

[Phil Rea]

In simpler terms the first stages are as follows.

Egg -> Nymph 1 (Eggs with legs) -> Nymph 2 (Mobile nymphs i.e. they can walk around) -> Spiderling.

I'm led to believe that some sp. can also have a Nymph 3 stage but this is a major exception to the rule.

Juvenile is more complicated. My understanding is that a spider is generally considered a juvenile when its adult colouration can be seen.

Subadult is a matter of opinion. I would expect a subadult to be within a couple of moults of maturity

Technically, I guess, an adult is either a mature female or a mature male. Mature males will have emboli, and mature females will have well developed spermathecae (except for E. olivacea and S.longibulbi), and be breedable.

Hope that doesn't confuse the issue too much

Obviously classifying them by instar is more accurate, and some people will say things like 5th moult spiderling, so that can be used too.

[Johanna Turner]

Thanks both!
Makes a bit more sense now!

[Michael Jacobi]

Hello Johanna,

One thing that might prove confusing is a few differences in terminology between US keepers and Brits and other Europeans. The terms Phil posted aren't used in the US. I realize you are from the UK and this is a UK forum, but it might be helpful to be aware of these differences. US terminology in bold.

From Phil's post:

Egg -> Nymph 1 (Eggs with legs) -> Nymph 2 (Mobile nymphs i.e. they can walk around) -> Spiderling

egg = embryo
nymph 1 = postembryo ("eggs with legs")
nymph 2 = 1st instar ("mobile, pale-colored nymphs")
spiderling = 2nd instar ("fully-pigmented, feeding nymphs")

instar = entomological term for an insect or arachnid life-stage separated by ecdysis (molting); these life-stages are properly known as "stadia" (singular = "stadium")

As Phil correctly noted, some species (e.g., Poecilotheria formosa, P. metallica) don't reach "spiderling stage" until 3rd instar. That is, they have an additional molt before they become "fully pigmented, feeding nymphs".

Of course, there are other exceptions: for example, although we use the "feeding nymphs" description for spiderlings, it is documented that even 1st instar nymphs may feed by cannibalism.

The term "spiderling" is used as slang for any early instar tarantula. Technically, with each successive molt it becomes 3rd instar, 4th instar... 9th instar, etc. So, the terms you asked about, such as "spiderling, juvenile, subadult" are really arbitrary terms used in the hobby to give an approximation of size/life stage. I don't believe I have ever seen someone advertise a spider or a post a photo and call it, for example, "11th instar". Terms used for other animals such as reptiles (e.g., "subadults") just seem less cumbersome. And what an "11th instar" actually is depends on the species. For example, in fast maturing species such as Pterinochilus murinus or Poecilotheria regalis an 11th instar might be sexually mature, whereas in slow growing species such as Grammostola rosea an "11th instar" would be less than half grown.

So, how you apply these arbitrary and admittedly vague terms is up to your discretion. Let's just say you have a Brachypelma smithi... how would you classify it with these arbitrary terms - smaller than 1.5" in legspan as spiderling? 1.5-3.5" juvenile? 3.5-4.5" subadult? 4-5-6" adult? These would be reasonable, but obviously would be open to great debate and differ from keeper to keeper. When I was still a spider dealer, I applied these terms similar to how I have in my example; that is, based on the maximum/adult size of the particular species. A buyer gets a pretty good idea of what a subadult G. rosea is, but would likely be confounded by an 18th instar

Other technical terms worthy of note are "penultimate", "ultimate" and "postultimate". I believe the link Rhys provided can help you with these. It is easy to determine when a male is "ultimate", that is, has molted to sexual maturity and, should he molt yet again, "postultimate", but in females these terms are a bit more difficult to discern.

Kind regards, Michael

[Johanna Turner]

instar = entomological term for an insect or arachnid life-stage separated by ecdysis (molting); these life-stages are properly known as "stadia" (singular = "stadium")


So, how you apply these arbitrary and admittedly vague terms is up to your discretion. Let's just say you have a Brachypelma smithi... how would you classify it with these arbitrary terms - smaller than 1.5" in legspan as spiderling? 1.5-3.5" juvenile? 3.5-4.5" subadult? 4-5-6" adult? These would be reasonbable, but obviously would be open to great debate and differ from keeper to keeper. When I was still a spider dealer, I applied these terms similar to how I have in my example; that is, based on the maximum/adult size of the particular species. A buyer gets a pretty good idea of what a subadult G. rosea is, but would likely be confounded by an 18th instar

Was excellent to get an understanding of the term 'Instar' at last, and that was an incredibly informative response!

It's one hell of a lot clearer to me in laymans terms now!

As you suggest, each country may refer to things differently, as will individuals, and as such I appreciate everybody who has responded to my query.

And I liked your reference there to what you would class as 'Juvenile' dependant on the species and it's growing rate!

Thanks again that was just what I was looking for!

J

[J M Clegg]

Johanna, never mind the technical terms, being a Yorkshire man i would say about £35!

£3 - £5 for a sling
£10 - to £20 for a Juvinile
and around £20 to £40 for an adult.....

So thats the way to differentiate in Yorkshire!!!!

[Colin D Wilson]

Johanna, never mind the technical terms, being a Yorkshire man i would say about £35!

Ah... brings back fond down to earth childhood memories of my time in yorkshire when visiting relatives.
"Say what you mean and mean what you say" thats the motto eh Mr. Clegg.

"You can take the man out of Yorkshire but you can't take the yorkshire out of the man" as my Uncle used to say.

[Johanna Turner]

Superb! No messing about, that's what I like to see! :0)