M.robustum adult male sizes?????

[treeweta]

I have a sub adult male who hasnt moulted for a year or fed in many months, hes now in pre moult so i suspect that he might mature out when he moults later this week.

Considering this species supposed large size he seems really small. Compared to his female siblings who are now 2 moults ahead of him I suspect that if he does mature out next moult he will have a leg span at least 6 inches, maybe 6.5. As this is a leggy spider that gives him quite a small carapace. In fact hed be much smaller than a megaphobema mesomelas male i had years ago, similar leg span but a smaller head.

Any body out there can give rough sizes for adult males of this species? Once mine moults i'll repost regarding his maturity or not. It seems obvious to me that as 'big' as these are supposed to be they are not in the same league as salmon pinks for eg

 

[Moltar]

There's a couple of things about your post i don't get. How are you so sure he'll mature next molt? Also, usually females grow more slowly than males, so if the two females are 2 molts ahead and they're from the same sac... are you sure of their respective genders?

Some species the male is quite a bit smaller than the female. I'm not real familiar with M robustum but assuming you're right about him hooking out next molt i think you just answered your own question.

I've read that they can grow to 8"-9" so a 6.5" MM doesn't sound too out of the question to me. I've seen MM l parahybana's about that size and we know how big they CAN (not necessarily always DO) get.

 

[lucanidae]

8 inches for M. robustum is really a ridiculous size. Females rarely get above 6.5 inches even by the most liberal measurers. I've had mature males between 5 and 6 inches, but you are correct they tend to be extremely leggy with a small carapace.

 

[treeweta]

There's a couple of things about your post i don't get. How are you so sure he'll mature next molt? Also, usually females grow more slowly than males, so if the two females are 2 molts ahead and they're from the same sac... are you sure of their respective genders?

Some species the male is quite a bit smaller than the female. I'm not real familiar with M robustum but assuming you're right about him hooking out next molt i think you just answered your own question.

I've read that they can grow to 8"-9" so a 6.5" MM doesn't sound too out of the question to me. I've seen MM l parahybana's about that size and we know how big they CAN (not necessarily always DO) get.

I have 3 specimens, all sexed (correctly). they all got to the same size a year ago but since then the two females have moulted twice each, the male hasnt and not fed for about 6 months. The reason I am guessing hes going to mature out is the long time between the last moult and its imminent one, sure, thats not a given by any account and its more a guess on my part given that the 6 month fast and 1 year since its last moult suggests that something 'significant' might be ahead, ie maturity.

 

[treeweta]

8 inches for M. robustum is really a ridiculous size. Females rarely get above 6.5 inches even by the most liberal measurers. I've had mature males between 5 and 6 inches, but you are correct they tend to be extremely leggy with a small carapace.

ah, 6 inches or so, well i that case this is probably a normal sized male. my females are about 6.25 inches and i guess now they are a moult away from their yearly moult size, im sure they will get to 7 inches, sure they have chunky back legs but they are still quite lightyl built compared to many.

 

[treeweta]

said male is now on his back for a moult, i'll repost later to mention if indeed he's an adult!.....................and several hours later hes moulted and NOT adult!! well that put paid to my suggestion that his year long interval since his last moult was somehow connected to his imminent maturity! I would imagine that his next moult will have him mature out.

Judging by the females skins (who were 2 now 1 moult ahead of him) id guess hes now at 5.25 inches which could make him a 6.25-6.5ish inch adult if he matures next time which seems to be about normal? for this species. this doesnt quite tally with what i said in my first post but time and a ruler will tell!!

edit. his skin from the moult if 5 inches, so now hes about 5.5 (im using the females skin at the same stage to estimate that), so assuming he does mature next and males do get long legs on maturity he could well be 6.5 so my initial worry of having some tiny male were unfounded, hopefully i wont have to wait another year before he matures.