Embarressed to ask this - what are slings?

[Mandy Green]

Hi

I am some what embarrassed to ask this question as it seems quite a basic thing I should know being a T keeper. I only have one though and I got him as a sub adult.
I am looking around for another one and note they have juveniles and sling. What exactly is a definition for a sling if that is the right way to say it. Is this just really small baby ones?? Sorry for my niavity but I thought best to ask as I am sure all of you know and knowledge is power and all that.
Thank you for your patience and for any help with this???!!! ( and for my spelling!)

[Toran Tanner]

yep small baby one's is right

[Elaine Ross]

Hi Mandy
No need to be embarrassed about your question. It took me while to figure out what a sling was until I was told it was short for spiderling (baby spider). We all start somewhere and learn along the way. I'm still pretty new to T's so will probably have many questions still to ask.

Elaine

[Andy Miller]

You dont know if you dont ask, ask as many basic questions as you need thats what this site is all about anyway (helping each other)

[Nicola Dolby]

I wouldn't worry, if you don't ask you'll not find out. I'm still trying to work out what 'gravid' means.

[Mike Conabeer]

Nicola, A gravid female is the equivalent to a pregnant one, basiclly a mated female that is showing signs of producing eggs, not always 100% accurate with spiders as people tend to feed mated females more heavily so they automatically put weight on!

Mike.

[Nicola Dolby]

Thanks Mike

[Ray Gabriel]

Hi Mandy

a sling is a spiderling with the pider removed, less to type and pronounce.

I always thought gravid refered to something which lays eggs and pregnant refered to something whitch gives birth i.e. humans are pregnant not gravid??

Could be wrong??

Ray

[Mike Conabeer]

Perfectly correct I believe Ray, I was using pregnant as the closest descriptor to gravid, something which everyone can relate to, but yes I think gravid is usually only used to refer to egglayers.

Mike.

[Michael Jacobi]

I always write "sling" as "s'ling"; that is, as a contraction to show that letters have been removed. No matter how you spell it, "sling" is just a part of the hobby vernacular and its use is ubiquitous. It is basically synonymous with "early instars".

Much harder to define than the creation of the slang is to what "spiderling", "sling" or "s'ling" refers. At what point does a "sling" become a "juvenile"? When it molts from 7th instar to 8th? Impossible as, for example, Poecilotheria grow quickly and Grammostola grow slowly. In other words, it is nothing more than a vague term that gives some idea of age and is difficult to define. One person's "large spiderling" is another's "small juvenile". Exact measurements of body length or diagonal legspan are much more useful, but how many people are going to disturb each spider and put calipers on it?!? Personally, I call them spiderlings (or "s'lings") until they are at about 6th instar and can be accurately sexed by molt/microscope, then they are "juveniles".

To semi-briefly comment on an even more controversial term - "gravid":
There are two definitions of the word. The more precise and conservative definition would not allow for a tarantula to "be gravid". By that definition, a gravid animal contains fertilized embryos, and since tarantula eggs are fertilized at deposition "gravid" would be inaccurate. It would be akin to calling a fish "gravid". The term gravid is most commonly encountered in the reptile hobby and snakes & lizards that have ovulated after being mated are called "gravid". However, a dart frog couldn't be "gravid" as the male fertilizes the eggs after they are laid. Essentially the term is, as Ray wrote, the egg-laying equivalent of "pregnant". (However, it gets more complicated as it is also used for "live-bearing" reptiles like boa constrictors. That is because "live birth" in reptiles is much more closely related to egg-laying than true live birth as in mammals). So, in the strict sense of the word, a tarantula cannot be gravid - a point that has been argued by many including myself at one time. However, one day I decided to do something crazy... actually open a dictionary! And, after years of defining "gravid" only one way, to my horror I discovered definition number two. It has a more liberal use - to carry eggs. Some dictionaries might limit it to carrying developing young or eggs, but even this definition could be broadly applied to tarantulas. With or without development or fertilization, "gravid" can be used even if it isn't as accurate as "mated tarantula" or "tarantula full of eggs". Incidentally the word "gravid" is derived from the Latin gravidus or gravis, meaning "heavy". And by that, "gravid" could also apply to me!

All the best, Michael

PS - As long as I am at it and my coffee is still hot... I imagine some readers also won't know the definition of "instar":

Arthropod development goes through stages called stadia (singular: stadium), which are separated by the sloughing of the exoskeleton. Here's where it gets a little confusing... Brits and Europeans like to use terms that I abhor - "nymph-1" and "nymph-2". Yuck! A tarantula (or any spider) begins life as an embryo - a fertilized egg. Inside the sac it develops and becomes a postembryo - what is [unfortunately] also referred to as "nymph-1". When the postembryo molts it becomes a motile, but unpigmented nymph that is a 1st instar (one molt). This is your "nymph-2". It's next stadium takes it through ecdysis again (molting) to 2nd instar, which in most species is a fully-pigmented, fully-motile, feeding mini-tarantula now referred to as a "spiderling" (or sling or s'ling). [Note: I wrote in most species because in some (most notably P. formosa, P. metallica) there is an extra developmental stage and "nymphs" do not become "slings" until 3rd instar]. Every time the spider molts (successive stadia), it becomes 3rd, 4th... 9th, 10th... instar, etc. Technically, you could refer to your adult Brachypelma smithi as a 28th instar, for example, even if it would be a bit silly.

[Elaine Ross]

Thank you Michael for the explanation. I will probably have to read it a few times over to let it sink in a bit. You have certainly answered a few questions that us newbies to the hobby would probably ask at some point along the way.
I appreciate you taking the time to type it all out
Elaine

[KJ Vezino]

Michael, thanks for that great write up!

Assuming the first definition of the term gravid is the most correct, lets throw out the looser definition and assume that gravid does not technically apply to tarantulas.

Now, what do you propose as the term that best fits the mated female that is just carrying eggs?

[Nicola Dolby]

Thanks again Mike and Ray. So if someone 'with child' is pregnant then a bird, tarantula or whatever 'with eggs' is gravid. Thats your answer Kevin, if your Grammostola or Brachy has been successfully mated she is gravid. Whew!!

[Michael Jacobi]

Thanks again Mike and Ray. So if someone 'with child' is pregnant then a bird, tarantula or whatever 'with eggs' is gravid. Thats your answer Kevin, if your Grammostola or Brachy has been successfully mated she is gravid. Whew!!

Not quite. That is only "the answer" if we are willing to concede that the use of a broad definition of the term "gravid" is the most acceptable for our purposes and I, for one, am not ready to do that. I was just explaining that doing so is not, technically, incorrect.

A bird or reptile is certainly gravid when carrying eggs as it fertilizes them during ovulation. But, as Kevin wrote, I would prefer to apply the narrow definition of the term for arachnocultural use, and to answer Kevin's question, I think "mated female" is much more accurate than "gravid female" when it comes to theraphosid spiders and, at least for now, superior to any other designation. But I will be brainstorming to see if I can come up with something even more satisfactory than "mated female", since a female can obviously be "mated" but yet to ovulate. Perhaps "ovulated female" is better...

In short, in a broad sense a mated female tarantula that acquires a swollen opisthosoma that can be reasonably presumed to be the result of post-mating ovulation can - technically - be referred to as "gravid", but it would be more accurate to reserve that term for organisms that carry fertilized developing eggs than for those, like tarantulas, that don't.

Best, Michael

[Colin D Wilson]

Right Michael

After reading all your above notes and using some of your terminology, adding a bit of arachnological humour and thinking VERY hard as i write this

A scorpion, when mated is an ovulated female, who then becomes gravid as the embryo's develop inside her, she's then considered pregnant in the short time as the embryos leave their embyonic sacs and develop into 1st instar scorp'lings, she then gives live birth and the after a few weeks the scorp'lings subsequently moult into 2nd instar (which is only their first moult outside the confinds of their mothers body)

Not scientific "Gospel" but added confusion non the less