What exactly does a fat abdomen look like?

[CheshireKitty]

Hello! So, new to tarantulas and I've been reading all sorts of posts that say to tailor their feeding schedule based on how "fat" the tarantula's abdomen looks. Except I can't seem to find any clarity on what exactly constitutes a fat abdomen. Half of the carapace? Same as the carapace?? Larger???

Attached are some photos of the Ts...I'd appreciate if someone could tell me whether they look skinny, average, or fat...

 

[coolnweird]

Hello and welcome to the hobby! When people talk about fatness of the abdomen, it's always in comparison with the carapace. Generally you want the carapace and the abdomen to be about the same size, but there are exceptions.

A chunky booty is less of a concern for slings and juveniles, who have somewhere for that stored energy to go during their next molt. Adults don't have any need for a large reserve of energy, and a fat adult will molt and still be fat! A large, heavy abdomen can drag along the ground and develop sores and cysts, so for adults I recommend keeping the abdomen around the same size as the carapace, slightly bigger is okay. For slings, I allow them to get fatter, with the abdomen being about 1.5-2x the size of the carapace!

Your spiders all look healthy, the only one who looks a chunky is the sling in the first pic, but I still think for a sling it's okay. The other two look perfectly proportioned!

 

[Isaax Critterz]

what species is that?

 

[CheshireKitty]

Hello and welcome to the hobby! When people talk about fatness of the abdomen, it's always in comparison with the carapace. Generally you want the carapace and the abdomen to be about the same size, but there are exceptions.

A chunky booty is less of a concern for slings and juveniles, who have somewhere for that stored energy to go during their next molt. Adults don't have any need for a large reserve of energy, and a fat adult will molt and still be fat! A large, heavy abdomen can drag along the ground and develop sores and cysts, so for adults I recommend keeping the abdomen around the same size as the carapace, slightly bigger is okay. For slings, I allow them to get fatter, with the abdomen being about 1.5-2x the size of the carapace!

Your spiders all look healthy, the only one who looks a chunky is the sling in the first pic, but I still think for a sling it's okay. The other two look perfectly proportioned!

Thank you! I was wondering about the sling, its rear end is quite chonky relative to the rest. But it also eagerly took down a pinhead roach today so...

what species is that?

The sling is an a. geniculata, the second photo is a GBB, and the arboreal is a c. versicolor!

 

[fallonzoey]

My A. Geniculata is EXACTLY the same way. Very fat booty, but still eagerly takes down prey.

 

[Liquifin]

To answer your question, it would be dependent on the species and size ratio of the abdomen to the species itself. Not all tarantulas will have circular abdomens for being overweight as some tarantulas will have smaller or thinner/longer looking abdomens than other species. So know your species and know what is the right and healthy proportions of the abdomen size to that particualr species.

 

[ladyratri]

So know your species and know what is the right and healthy proportions of the abdomen size to that particualr species.

There are photo threads by genus you can look at for a nice wide range of healthy specimens -- pretty safe to assume they show a rangen from thin but reasonable to chunky but reasonable.

The change with slings is pretty dramatic.

Pre molt A. purpurea in the stage we call "two legs fat":

Same spood, one small cricket after that molt, looking all kinds of svelte again:

 

[coolnweird]

To answer your question, it would be dependent on the species and size ratio of the abdomen to the species itself. Not all tarantulas will have circular abdomens for being overweight as some tarantulas will have smaller or thinner/longer looking abdomens than other species. So know your species and know what is the right and healthy proportions of the abdomen size to that particualr species.

Thank you for mentioning this, I wasn't sure how to word this sentiment in my original answer!

 

[fallonzoey]

I decided to take a pic of my lil chunker A. Geniculata. It just ate on the 19th. From the side
Front View
View from above
C.Versicolor

 

[viper69]

When it blots out the sun

 

[Westicles]

I decided to take a pic of my lil chunker A. Geniculata. It just ate on the 19th. From the side View attachment 429360
Front View View attachment 429361
View from above View attachment 429362
C.Versicolor View attachment 429363

Your geniculata is about to pop.

 

[IntermittentSygnal]

I second that. Mine Genic looked just like that, all shiny and large, until day before yesterday, when she molted.

 

[Marlana]

I wouldn’t worry about ‘overfeeding’ a sling. I think people get way too caught up with it and end up under feeding which can lead to molt issues. Slings NEED to be fat before their next molt or you risk them not molting properly. And how fat they need to be probably depends on species and how much size is going to be gained during the molt, so not really predictable as it varies wildly. I don’t stop feeding slings. If they will eat, I will feed them. There’s definitely a balance, you shouldn’t be feeding everyday. But going off abdomen size just doesn’t make sense to me.

Adults are completely different and you should be feeding appropriately so they don’t get absolutely huge especially when they aren’t going to molt is quite awhile. Most of my adults molt once a year at most. I do let them get fatter when I’m expecting a molt soon but not to the point they are dragging their abdomen or look ready to pop.