Autor Thema: spider on broom => Haplodrassus sp.  (Gelesen 466 mal)

Johan Verstraeten

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spider on broom => Haplodrassus sp.
« am: 2020-03-25 16:38:23 »
I found this spider on broom in dry heathland.
It has a body length of approx. 6-7mm
Location : Maasmechelen, Belgium
Date :25/03/2020





Best regards
« Letzte Änderung: 2020-03-29 23:08:34 von Tobias Bauer »

Simeon Indzhov

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Re: spider on broom
« Antwort #1 am: 2020-03-25 16:56:59 »
Hm, this should be a young Scotophaeus, but what is it doing in this habitat?
Simeon

Johan Verstraeten

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Re: spider on broom
« Antwort #2 am: 2020-03-25 17:53:54 »
it used to be an old sand quarry. There are some rocks on the ground. No houses in the area.
Heathland, pine trees on the borders and small birch.
Some small pools spread in the area.

Satelite photo :
https://waarnemingen.be/observation/187202589/

Simeon Indzhov

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Re: spider on broom
« Antwort #3 am: 2020-03-25 18:33:28 »
Pine trees don't sound bad!

Tobias Bauer

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Re: spider on broom
« Antwort #4 am: 2020-03-26 09:23:06 »
To, me, the eyes seem not to fit, the're not round, but shaped like an almond. The light covers a part of the eye field and makes them look smaller, and various Haplodrassus sp. are very common in such habitats. With a certain angle and light, the distance between the PME can also look different (wider). See here in H. moderatus.

https://wiki.arages.de/index.php?title=Haplodrassus_moderatus#/media/File:Haplodrassus_moderatus_female_A5980_PL1432.JPG

Tobias

Simeon Indzhov

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Re: spider on broom
« Antwort #5 am: 2020-03-26 09:29:58 »
I am not convinced. It has the characteristic narrow clypeus and small, forwards protruding chelicerae for Scotophaeus (Haplodrassus are pretty robust), the eyes seem round - less separated anteriorly than posteriorly, and the distal segments of legs I seem distinctly thickened (on photos, Haplodrassus seem to have thickened femora only)

Tobias Bauer

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Re: spider on broom
« Antwort #6 am: 2020-03-26 09:53:43 »
Johan, can you attach it in higher resolution? So that we can see the eyes.

Tobias

Simeon Indzhov

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Re: spider on broom
« Antwort #7 am: 2020-03-26 09:58:38 »
Perhaps also cropped? Is this the only photo?

Tobias Bauer

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Re: spider on broom
« Antwort #8 am: 2020-03-26 15:06:18 »
Maybe we both are wrong and its Echemus, that would be surprise  :P

Simeon Indzhov

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Re: spider on broom
« Antwort #9 am: 2020-03-26 15:51:58 »
This is something I also briefly thought of. As far as I remember (I haven't seen one in a long time), Echemus resembles somatically Scotophaeus, also in terms of eyes. I have an adult and a subadult male somewhere, I could dig them up and at least see if there are any blatant contradictions

Johan Verstraeten

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Re: spider on broom
« Antwort #10 am: 2020-03-29 12:14:00 »
I added 2 photos.

Simeon Indzhov

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Re: spider on broom
« Antwort #11 am: 2020-03-29 14:02:43 »
Hm. Odd. It does have closely situated to each other eyes! Like Haplodrassus silvestris, for example. But juvenile Scotophaeus have proportionally larger eyes, on the other hand, as do Echemus...

Tobias Bauer

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Re: spider on broom
« Antwort #12 am: 2020-03-29 14:26:22 »
It does certainly not look like that (narrow prosoma, chelizerae!)

https://wiki.arages.de/index.php?title=Echemus_angustifrons#/media/File:Echemus_angustifrons_prosoma_fem_Arne_Fjellberg.jpg

or that (round eyes clearly separated)

https://wiki.arages.de/images/b/bd/Scotophaeus-blackwalli_Sardinien-IsolaCaprera_14-07_01-female-detail.jpg

So, I think there is little doubt that this is a Haplodrassus, possibly sylvestris. I highly doubt that juvenile spiders change the form of the eyes during development from that shown by Johan to one of the examples above…

Tobias

Simeon Indzhov

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Re: spider on broom
« Antwort #13 am: 2020-03-29 16:04:58 »
I doubt it too - the triangular eyes are well visible on one of the photos