Autor Thema: Paroligolophus agrestis  (Gelesen 1607 mal)

Anes Pitrio

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Paroligolophus agrestis
« am: 2016-09-13 21:50:40 »
I'm sorry. I posted this question in the wrong forum.  :-[

I am hoping that someone can confirm that the spider in the attached photo is an immature Paroligolophus agrestis male. I do not think that the genital operculum matches a female. I cannot make better photos without a microscope. I do not want to sacrifice this species. I like to spare lives. I love and respect all living things and it pains me greatly to sacrifice a species for identification.

Anyway, I believe that this is an immature male Paroligolophus agrestis. Anyone agree or disagree?

operculum.jpg
*operculum.jpg (127.21 KB . 424x314 - angeschaut 206 Mal)

I have no experience with this species. The illustration in the Harvestmen: Keys and Notes for the Identification of the Species book shows two dots on the operculum of the male; which are not present on the species that I have collected.

https://books.google.de/books?id=2PcUAAAAIAAJ&pg=PA66&lpg=PA66&dq=Paroligolophus+agrestis+male&source=bl&ots=9UXT1nqcyI&hl=en&sa=X&redir_esc=y#v=onepage&q=Paroligolophus%20agrestis%20male&f=false

Stephan Lauterbach

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Re: Paroligolophus agrestis
« Antwort #1 am: 2016-09-14 06:57:35 »
Hi Anes!
Please pardon my english, I think I need more pratice..;)

I just know the german species of harvestmen (it is no spider by the way ;), but the notch on the genital operculum is typical for Paroligolophus agrestis.

I'm very shure it's an adult female. The genital operculum of juvenils and subadult are usually more flattend and lie deeper between the coxa. The notch of the male is more pincer-shaped, because of the very thin and long penis.

I'm no expert, but in this case i'm very shure. Do anyone agree?

Anes Pitrio

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Re: Paroligolophus agrestis
« Antwort #2 am: 2016-09-14 10:56:05 »
Hallo Stefan  :)

I do not know the terminology for the anatomy of Harvestmen, so I do not know what to name the groove in the middle of the operculum. The groove is why I think that it is a male. The photos on the wiki show the female and male operculum:



Female=top photo; male=bottom photo.

I do not know where the penis is located. I suspect that the penis is a part of the palp. yes? no?
I wonder if the penis is a part of the operculum. The groove in the middle of the operculum might be the penis.

The operculum of the spider in my photo does not look exactly like the operculum in the photo on the wiki.

I know nothing about this species. Therefore, if you think that it is a female, then it is a female. You are more knowledgeable.

Regarding being an immature: I was judging by appearance. The color of this species does not match alot of photos but it could be variable. I figured that this species is not a full adult. In the insect world, I would say final instar nymph. I was just guessing based upon appearance.

I Thank You Very Much for helping. I appreciate your time and effort. I will consider this to be an adult female.

I hope that you have a Wonderful day  :)

Rainer Breitling

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Re: Paroligolophus agrestis
« Antwort #3 am: 2016-09-14 12:45:24 »
Harvestmen are not my area of expertise, but I think that this is obviously not a female, nor a subadult, but a mature male specimen. If I am not mistaken, one can clearly see the penis shining darkly through the operculum, which has a rather shallow indentation at the tip, not pincer-like as in the female (and, no, the penis is not part of the palp, as harvestmen use a very different approach to copulation than spiders).
Best wishes,
Rainer

Stephan Lauterbach

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Re: Paroligolophus agrestis
« Antwort #4 am: 2016-09-14 14:49:17 »
Hi !

Now i'm very confused. I just remembered that the deep notch had something to do with stabilisation of the penis during the copulation.

The penis lies beneath the operculum genitale as it does the ovipositor of the female.

After lunch I will take photos of speciemen I have in my collection. ;)

Stephan Lauterbach

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Re: Paroligolophus agrestis
« Antwort #5 am: 2016-09-14 15:52:11 »
Sorry for the confusion! I was wrong. I looked it up and realised that Martens has a wrong  legend for his drawings of the operculums. But in the text he writes, that the female has the pincer-shaped notch.

here a picture of a female,with the deep notch and the ovipositor:

pagrestisfemale.PNG
*pagrestisfemale.PNG (423.53 KB . 484x359 - angeschaut 163 Mal)

so you were totally right! Your p.agrestis is a male!

Anes Pitrio

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Re: Paroligolophus agrestis
« Antwort #6 am: 2016-09-14 17:09:29 »
@Rainer

Thank You so very much. You have helped me learn more about this species. I like the Harvestmen. Interesting animals indeed. I've never seen this species before. I was looking at the photos I had made and I figured that the groove in the middle should be the penis. Yet, I have not seen them mating, so I could not be certain.

I am happy that you have helped me. I doff my hat to you Sir. Thank You for your time and effort. You are Great.  :)

Anes Pitrio

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Re: Paroligolophus agrestis
« Antwort #7 am: 2016-09-14 17:13:13 »
@Stephan

You are Wonderul for taking time out of your day to help me. I was excited to see that someone posted an answer. I appreciate all that you have done for me.

I'm not confused because I am just learning technical details about spiders and harvestmen. You made time to evaluate your reply, then correct the information. That is Great! I Thank You for all that you have done for me. I am a happy man.  :)

Anes Pitrio

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Re: Paroligolophus agrestis
« Antwort #8 am: 2016-09-14 17:18:33 »
Before I consider this thread resolved, I have one more question. I hope that anyone can help.

I have no idea how scientists measure animals because my measurements usually do not match that which is published in books. For example, the male Paroligolophus agrestis in question measures 4mm not counting the palps(?) If one is to count the palps(?) sticking out from the face, then the harvestmen measures 4.5mm. Which one is correct?

I have the same problem with grasshoppers. I really respect Mr. Heiko Bellmann's work but his measurements confuse me. I found a Tetrix subulata and my measurement is not even close to Mr. Bellmann's work. I have no idea what he is measuring because he never states a starting point and ending point.

basically, the starting point should be the tip of the face to the tip of the abdomen (in my opinion).

I have attached a photo with my confusion in colored boxes:

size.jpg
*size.jpg (80.5 KB . 300x200 - angeschaut 166 Mal)

so is this male 4mm or 4.5mm? or something else?

Thanks  :)

Emmanuel Delfosse

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Re: Paroligolophus agrestis
« Antwort #9 am: 2016-09-14 18:31:02 »
Yes, we can see the penis by transperency.

For measurements: only the body (prosoma and opisthosoma), not chelicerae and not pedipalps (same for the spiders).

For Orthoptera measurements see this link: http://bernard.defaut.perso.sfr.fr/pdf/1_Taxonomie/Defaut_2012c_Biometrie_types_Caeliferes_francais_1_et_2_light.pdf

Emmanuel

Anes Pitrio

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Re: Paroligolophus agrestis
« Antwort #10 am: 2016-09-14 18:56:03 »
@Emmanuel merci beaucoup! la perfection  :)