@Stanley A. Schultz - this piece of information was very interesting and thank you for taking the time to share it with me/us.

Amore wrote: @Stanley A. Schultz - this piece of information was very interesting and thank you for taking the time to share it with me/us.

My pleasure. We aims to please.

BTW, the babies in that photo are NOT second instar. They're FIRST instar. The little devils are eating each other even before they can properly move and hunt!

And, I don't care what you say, there is no such thing as a truly communal tarantula. They may cohabit for a time as long as conditions are peachy. But, let conditions deteriorate even a little and you begin to lose tarantulas.

It's been said that the human species is only 9 meals from anarchy . It's only about 1 or 2 among the so-called communal species of tarantulas.

Are those babies not eggs with legs (nymphs) that only moult into first instars at their next moult? With most species beginning to feed only at second instar.
Probably one of the things that I dont totally agree on with your naming of instars.

Very interesting! Learing so much!

Ceratogyrus wrote: Are those babies not eggs with legs (nymphs) that only moult into first instars at their next moult? With most species beginning to feed only at second instar.
Probably one of the things that I dont totally agree on with your naming of instars.

Now here we have a bit of a problem.

First, it's not my system or systems. I'm merely parroting what the big boys in the white lab coats are telling me.

Second, there are two, competing and conflicting systems for naming the various stages in the development of spiders. The Europeans use one system and the Americans use a different one. Because I was born in America and have been a Canadian resident for decades, I follow the American system. Frankly, the European system confuses me. (Edit: I found out from Foelix' book that there are in fact several disparate naming systems. See below.)

Third, many of those enthusiasts who bother to think about the matter don't understand that schism, or that a schism even exists, and try to meld the two into some synthesis that confuses everybody!

By Downes' system (the American one), the egg is enclosed in a shell or membrane called the chorion. The chorion is produced by the mother as the initial packaging.

When the embryo casts off this membrane it is said to "hatch." The resulting creature is called a "postembryo," and I think that's equivalent to the European "nymph." Because the covering wasn't made by the embryo, this is not considered a true molt. And, the resulting stage is not considered an instar because an instar is defined as the stage AFTER A MOLT. And, the first instar follows the first molt. (And, the term "eggs with legs" is used only by enthusiasts and amateurs. It isn't part of either naming system, and the professionals don't use it. Except as a vernacularism, it has no meaning or significance.)

However, from that time onward, every time the creature casts off a covering, the covering will have been made by the creature itself (not its mother), that will be considered a molt and is appropriately numbered, and the following stage in development is called an instar and inherits the number of the molt that produced it.

The major issue with this whole thing is that, while the concepts and the nomenclature are very simple, trying to explain it in writing gets really complex and confusing. You need to read that sentence 6 times, a word at a time, before you can sort it all out.

Since South Africa isn't a part of the Americas (Duh!), but has a strong European history and background (actually so do we, but that's a different story), I presume that you'll follow the European system. Maybe someone on this forum knows in fact what that is (or can supply a link) and can enlighten us. Then, we can construct a diagram correlating the two systems. And I (if no one else) can breathe a little easier. :laugh:

But, all this is missing the original points of my posting:

1> Predation and cannibalism begin very early in the lives of tarantulas. Much earlier that we might otherwise assume.

2> Not even the so-called communal species are free of cannibalism. Apparently the inhibition for eating one's brood-mates doesn't develop until sometime AFTER the babies leave the eggsac. One might postulate that it's a secondarily acquired instinct or instinct modification, and that could potentially open a whole different discussion about the inheritance or development of instincts in general, and among tarantulas. How about we let that one die quietly for now, shall we?

Lastly, I have tried to find the original data surrounding Ryan's photograph, but have been unsuccessful. I don't have it in my own files and I cannot find it on the 'Net. So, I have E-mailed Ryan to ask if he knew what instar or instars the babies in that photo were. The breeder, if he were paying attention, would know how many times the creature shed its covering, chorion or exoskeleton. And, that would tell us immediately what the developmental stage was.

More later, as new data develops.

Very interesting, thank you again for all the info. So much to learn!!