Psalmopoeus cambridgei MM?

[ErinM31]

I saw a reference to a mature male Psalmopoeus cambridgei hooking out, but have not been able to distinguish tibial hooks in photos. It looks like they get extra leggy upon maturation — are there any other physical indications?

This looks like a sperm web to me:

The broad bed of webbing was in place for the molt, but the smaller section of webbing built over it just appeared today.

 

[cold blood]

Their legs turn into pipe cleaners and the pattern on the rump fades a lot.

Those do look like sperm webs.

 

[Nightstalker47]

Yeah, this species does have tibial hooks. MMs should be easy to spot though, the change is very dramatic.

 

[ErinM31]

Their legs turn into pipe cleaners and the pattern on the rump fades a lot.

Those do look like sperm webs.

Yeah, this species does have tibial hooks. MMs should be easy to spot though, the change is very dramatic.

Thank you both for the info! There are definitely no tibial hooks and neither the proportions nor abdominal pattern have changed so my Psalmo is either not male, not mature or both. (I think it is male, but then I was *certain* from a very good molt that my B. hamorii was male — until she matured! So I don’t know. )

That webbing is curious though... Perhaps he is practicing?

 

[cold blood]

How big is it?

 

[The Grym Reaper]

Better to look for emboli in any case but there's a massive difference in appearance between immature and mature males.

Penultimate male
View media item 43914
Mature male
View media item 47405

 

[ErinM31]

How big is it?

Over 4” DLS, probably 5” with legs extended, but I will get a more accurate measurement when I can.

Better to look for emboli in any case but there's a massive difference in appearance between immature and mature males.

Penultimate male
View media item 43914
Mature male
View media item 47405

Thank you for sharing your photos! I can clearly see the emboli on the mature male. I had looked quite closely at my T’s pedipalps for any clue and there was definitely not the slightest hint of emboli.

I wanted to be sure, however, because in the past, I have at times been slow to recognize a mature male when I was not expecting it.

That webbing must just happen to look like a sperm web from the right angle — certainly this T webs a lot! Besides all the other signs indicating it is not a MM, all the sperm webs I’ve seen before were dismantled after use whereas this webbing remains undisturbed.

 

[The Grym Reaper]

Over 4” DLS, probably 5” with legs extended, but I will get a more accurate measurement when I can.

Good chance his next moult will probably be his maturing moult then, when mine hooked out the moult measured about 5", I'm guessing that'd be around average size for a male to mature at.

 

[ErinM31]

How big is it?

Got a better measurement — definitely around 5” DLS

Good chance his next moult will probably be his maturing moult then, when mine hooked out the moult measured about 5", I'm guessing that'd be around average size for a male to mature at.

Good to know, thank you! If after the next molt, they are not a mature male, I may really begin to think they are female after all — hopefully I will be able to tell from the molt as well! I got this one fresh but the abdominal region was so twisted about that I could not restore the relevant region to any informative condition.

 

[Ungoliant]

Good to know, thank you! If after the next molt, they are not a mature male, I may really begin to think they are female after all — hopefully I will be able to tell from the molt as well! I got this one fresh but the abdominal region was so twisted about that I could not restore the relevant region to any informative condition.

At 5", a female will be really obvious.

The molt is likely still usable. The abdomen is often twisted into a wad, but it can unfold:

1. Cut the abdomen off of the rest of the molt
2. Cut off the bottom of the abdomen below the second pair of book lungs. (Otherwise, it has a tendency to fold in on itself.)
3. Prepare a dish of water with a drop of dish soap to reduce surface tension. (Otherwise, the light molt has a tendency to float on top.)
4. Place the molt in the dish. Let it soak for up to five minutes (until it becomes pliable).

Lately, instead of removing the molt from the water before taking photos, I've been spreading it out in the water and taking the photo while it's in the water. It's a lot easier to spread the molt in water (it tends to fold on itself when you remove it), and the water acts as a diffuser of light.

Here is one I took using this method (a 2" female Neoholothele incei).

2" Female Neoholothele incei [molt sexing]

• Ungoliant
• Jun 18, 2018
• 1
• crazy legs exuviae female holothele incei holothele vellardi incei juvenile female molt neoholothele neoholothele incei sexing trinidad olive tarantula

See this thread for additional tips/instructions: How to Request Species or Sex Identification.

 

[ErinM31]

At 5", a female will be really obvious.

The molt is likely still usable. The abdomen is often twisted into a wad, but it can unfold:

1. Cut the abdomen off of the rest of the molt
2. Cut off the bottom of the abdomen below the second pair of book lungs. (Otherwise, it has a tendency to fold in on itself.)
3. Prepare a dish of water with a drop of dish soap to reduce surface tension. (Otherwise, the light molt has a tendency to float on top.)
4. Place the molt in the dish. Let it soak for up to five minutes (until it becomes pliable).

Lately, instead of removing the molt from the water before taking photos, I've been spreading it out in the water and taking the photo while it's in the water. It's a lot easier to spread the molt in water (it tends to fold on itself when you remove it), and the water acts as a diffuser of light.

Here is one I took using this method (a 2" female Neoholothele incei).

2" Female Neoholothele incei [molt sexing]

• Ungoliant
• Jun 18, 2018
• 1
• crazy legs exuviae female holothele incei holothele vellardi incei juvenile female molt neoholothele neoholothele incei sexing trinidad olive tarantula

See this thread for additional tips/instructions: How to Request Species or Sex Identification.

Thank you so much for the detailed instructions! I should have thought of soap — the water always does seem to roll right off! As temperatures are warming with spring, I should be getting lots of molts from different species! It would be lovely to know the sex of my psalmos and pokies. Thank you again!

 

[ErinM31]

At 5", a female will be really obvious.

The molt is likely still usable. The abdomen is often twisted into a wad, but it can unfold:

1. Cut the abdomen off of the rest of the molt
2. Cut off the bottom of the abdomen below the second pair of book lungs. (Otherwise, it has a tendency to fold in on itself.)
3. Prepare a dish of water with a drop of dish soap to reduce surface tension. (Otherwise, the light molt has a tendency to float on top.)
4. Place the molt in the dish. Let it soak for up to five minutes (until it becomes pliable).

Lately, instead of removing the molt from the water before taking photos, I've been spreading it out in the water and taking the photo while it's in the water. It's a lot easier to spread the molt in water (it tends to fold on itself when you remove it), and the water acts as a diffuser of light.

Here is one I took using this method (a 2" female Neoholothele incei).

2" Female Neoholothele incei [molt sexing]

• Ungoliant
• Jun 18, 2018
• 1
• crazy legs exuviae female holothele incei holothele vellardi incei juvenile female molt neoholothele neoholothele incei sexing trinidad olive tarantula

See this thread for additional tips/instructions: How to Request Species or Sex Identification.

I have given it a try with three molts:

My smaller (~4” DLS) Psalmopoeus cambridgei:

Do I see spermathecae?

One of my Poecilotheria rufiliata (~3” DLS) last night:

Absolutely nothing to see here, right? But I think they chewed on it and perhaps nothing is yet developed to see here?

My MF Hapalopus sp. Columbia large molted last October but I’d kept the molt as I’ve been trying to get a good photo:

Well, I wouldn’t know they were female by looking at this. I think their spermathicae are visible in an earlier photo attempt?

 

[Ungoliant]

I have given it a try with three molts:

I would upload these to the Spermathecae sexing (Molts) gallery, where they are more likely to be seen by those with a good eye for sexing.

 

[ErinM31]

I would upload these to the Spermathecae sexing (Molts) gallery, where they are more likely to be seen by those with a good eye for sexing.

Will do; I wasn’t sure if I was doing it right or perhaps I’m just limited by lighting and resolution.

 

[dangerforceidle]

Should be looking for structures like these in P. cambridgei: https://arachnoboards.com/gallery/psalmopoeus-cambridgei-juvenile-female-3-5.57302/. At 4-5" DLS, they should be quite apparent.