Penultimate v MM

[Jonoz]

I know this might be a dumb question but when male T first gets its palp bulbs/ tibal spurs, is it then penultimate or completely mature?

 

[spiderfield]

That makes him completely mature. Penultimate refers to the stage right before he gets those hooks or palp bulbs. Not a dumb question at all.

 

[Zoltan]

Spiderfield is right. When the male is mature, it's also called an ultimate male. Penultimate means one before the last, next-to-last. When a male is two molts away from being mature, it may be called an antepenultimate male.

 

[Warren Bautista]

After his final molt, most of the time they will not molt again, but in rare cases, the male may try to molt. These males usually pass away due to molting problems, although there have been a few documented cases in which males have survived a postultimate molt.

 

[Jonoz]

thankyou all for your help, i do have one more question on the topic; How do you tell when a male is penultimate? Or can you only tell that he was when he matures?

 

[Satellite Rob]

When he gets his bulbs and hooks.He then becomes a mature male.Before he
molted mature he was penultimate.

 

[spiderfield]

Basically if your male T has reached the average adult size for its species, but has not yet hooked out, you have to assume he's penultimate. This is the only way I know of determining penultimate status. Maybe the more seasoned keepers here know of a better way, but for me this is how I gauge it.

 

[rustym3talh3ad]

ok well im looking to get some pictures soon but i believe that my P. pederseni is either pen or MM, now, the reason im deciding it may be pen is becuz it looks as if there may be a embolus under the toe pad of the pedipalp but from the matures ive seen they have a small hooked end on a fully mature male, and NO im not talking about the tibial spurs im talking about the end of the pedipalp gets the bulbs but the end of hte bulbs have a small point on them....now the guy im looking at doesnt have those little bulb points but theres for sure sign of emboli, now would that be Penultimate or is there a physical difference between Penultimate and fully mature?

 

[equuskat]

ok well im looking to get some pictures soon but i believe that my P. pederseni is either pen or MM, now, the reason im deciding it may be pen is becuz it looks as if there may be a embolus under the toe pad of the pedipalp but from the matures ive seen they have a small hooked end on a fully mature male, and NO im not talking about the tibial spurs im talking about the end of the pedipalp gets the bulbs but the end of hte bulbs have a small point on them....now the guy im looking at doesnt have those little bulb points but theres for sure sign of emboli, now would that be Penultimate or is there a physical difference between Penultimate and fully mature?

The "little points" on a MM are not poking out all the time. They sort of stay folded back until needed. There is a huge physical difference between penultimate and mature. A penultimate male DOES NOT possess any palpal bulbs or hooks. A penultimate male may be leggy and leaner that a female, or he may not be. He does not look like a mature male. At all.

 

[rustym3talh3ad]

ok so then next question....who wants to 50/50 my MM P. pederseni lol. ;P

 

[codykrr]

agree with all the above. but want to add my .02 cents.

ok usually people who say they have a penultimate male have either had the spider since it was born and kept records of molts. or are just guessing completely. or are rather experienced and can tell.

now as far as telling if there penultimate. there are a few exceptions. depending on species. some gain swollen pedipals but lack the emboli. also i have personally noted with aphonopelma henzi, a penultimate male posses what looks like small bumps where the tibial hook will be present, nd has swollen pedipalps but lacks emboli. you have to truely examine the L1 and R1 legs to see these "bumbs" but they are there. and as said there really leggy and thin like a mm as well. and no thesebumps are not mistaken with acual tibial hooks. i know what they look like.

 

[rustym3talh3ad]

Pokies dont get Tibial Spurs do they???

 

[Nerri1029]

agree with all the above. but want to add my .02 cents.

ok usually people who say they have a penultimate male have either had the spider since it was born and kept records of molts. or are just guessing completely. or are rather experienced and can tell.

now as far as telling if there penultimate. there are a few exceptions. depending on species. some gain swollen pedipals but lack the emboli. also i have personally noted with aphonopelma henzi, a penultimate male posses what looks like small bumps where the tibial hook will be present, nd has swollen pedipalps but lacks emboli. you have to truely examine the L1 and R1 legs to see these "bumbs" but they are there. and as said there really leggy and thin like a mm as well. and no thesebumps are not mistaken with acual tibial hooks. i know what they look like.

I've not noticed this first hand, but it does make perfect sense.

These structures must be present prior to the maturing molt underneath the current exoskeleton.

However, I'll add/assume they will not be present just after the penultimate molt, but later when the new 'mature' skeleton is formed.

 

[codykrr]

However, I'll add/assume they will not be present just after the penultimate molt, but later when the new 'mature' skeleton is formed.

acually thats when it was the easiest for me to tell. was right after the penultimate molt while its still pretty fresh. i noticed it while it was lying on its back and then later examined him afterhe had hardened up.(about a week) you can really feel and see them pretty easy. not saying this applies to all species, but i belive it could be futher looked into. also like i aid i noticed the semi swolen pedipalps. but no emboli. truely awsome. but like i aid this wason a penultimate male A. henzi, but it does make me wonder how many others this occurs on.

 

[Nerri1029]

acually thats when it was the easiest for me to tell. was right after the penultimate molt while its still pretty fresh. i noticed it while it was lying on its back and then later examined him afterhe had hardened up.(about a week) you can really feel and see them pretty easy. not saying this applies to all species, but i belive it could be futher looked into. also like i aid i noticed the semi swolen pedipalps. but no emboli. truely awsome. but like i aid this wason a penultimate male A. henzi, but it does make me wonder how many others this occurs on.

So the penultimate exoskeleton "had room set aside" for these structures, for when they eventually form?
WOW.. THAT would be something to look into for other species !!!

I guess you could do ventral photographs and use software like "ImageJ" which would allow you to do measurements on the photograph.
Paying attention to ratios of leg segments to diameter, etc.

Hmmm

 

[ZergFront]

After his final molt, most of the time they will not molt again, but in rare cases, the male may try to molt. These males usually pass away due to molting problems, although there have been a few documented cases in which males have survived a postultimate molt.

Yeah, the authors discussed postultimate molt in my Tarantula Keeper's Guide. The bulbs or hooks would get caught in the old exoskeleton. One of the authors had one survive the molt but it had lost it's emboli and thus was useless as a breeder. I was about to start a new post asking about it but I searched 'postultimate' first and found this thread.

Has anyone here witnessed a MM in premolt and did anything to try and save it? I'm curious about how many die because of the molt and how many pass away from old age before the postultimate molt.

 

[AudreyElizabeth]

Apparently it has happened. I dug up this thread, although none of the links worked. http://www.arachnoboards.com/ab/showthread.php?t=6000&highlight=postultimate+molt+mature+male