mrt. 2010
Photo of the day (87): Simpulopsis
31-03-2010 22:03
These pictures are Simpulopsis cf. citrinovitrea (Moricand, 1836) and were taken by Adrián Gonzalez in western Ecuador, area of Junín.
Feedback welcome
30-03-2010 20:21
On my homepage you will now see a red feedback button. If you have any suggestion for improvements of the site, just click the button and give your suggestion. Your user voice will be heard!
SimpleMappr
30-03-2010 18:54
When you want to make a map with localities for a
paper or presentation, you often end up using rather
complicated methods involving several steps.
Today I found what seems to be a simple solution: SimpleMappr.
It is web-based map-making software, highly configurable and very easy to use. After a short test I think I’m going to love this one...
Today I found what seems to be a simple solution: SimpleMappr.
It is web-based map-making software, highly configurable and very easy to use. After a short test I think I’m going to love this one...
Carination again
29-03-2010 07:17
Some time ago I wrote about ‘evolution at work’ and
the phenomenon of carination
(see also this
and linked posts). During my trip in Peru I had
the opportunity to visit another locality where
carinated snails occur. It is in the Rio
Jequetepeque valley near Tembladera.
On the west side of Tembladera (located at the eastern end of the lake), Scutalus cretaceus (Pfeiffer, 1855) occurs. It was found hibernating on large rocks. East of the village S. baroni is found on rock-faces (pictures of a living specimen here).
When I was in Tucumán, I saw some lots - collected by Weyrauch - showing the transition between the two species. One series is shown above, but you’ll notice the different forms also in the lot shown below.
Since I strongly have the impression that Weyrauch mixed shells from an area (and also from different visits) into one lot, it is probable that these transitional forms were not found at one spot (and at one time).
Anyway, this raises questions like:
- How strongly demarcated is the hybrid zone between the two taxa?
- Is this zone determined mainly by a change in habitat? What is the role of the microclimate? Are there differences in soil or rock types? Can any of these factors considered to be the selective, driving force?
- How extended is the population of S. baroni and is there also hybridization with S. debilisculptus Weyrauch, 1967 which occurs at slightly higher elevation in the valley?
- Why is carination such a locally restricted phenomenon? And what is the evolutionary advantage?
On the west side of Tembladera (located at the eastern end of the lake), Scutalus cretaceus (Pfeiffer, 1855) occurs. It was found hibernating on large rocks. East of the village S. baroni is found on rock-faces (pictures of a living specimen here).
When I was in Tucumán, I saw some lots - collected by Weyrauch - showing the transition between the two species. One series is shown above, but you’ll notice the different forms also in the lot shown below.
Since I strongly have the impression that Weyrauch mixed shells from an area (and also from different visits) into one lot, it is probable that these transitional forms were not found at one spot (and at one time).
Anyway, this raises questions like:
- How strongly demarcated is the hybrid zone between the two taxa?
- Is this zone determined mainly by a change in habitat? What is the role of the microclimate? Are there differences in soil or rock types? Can any of these factors considered to be the selective, driving force?
- How extended is the population of S. baroni and is there also hybridization with S. debilisculptus Weyrauch, 1967 which occurs at slightly higher elevation in the valley?
- Why is carination such a locally restricted phenomenon? And what is the evolutionary advantage?
Photo of the day (86): Scutalus
26-03-2010 16:46
In the Rio Jequetepeque valley we visited the
Tembladera area, where we found Scutalus
baroni (Fulton, 1896). This is a species
occurring on steep rock-faces.
A specimen was kept alive till the return in Lima.
More on this species in the next post.
A specimen was kept alive till the return in Lima.
More on this species in the next post.
Peru trip
25-03-2010 16:32
In Peru I made two field trips. The first was to Rio
Cañete valley, Huancayo and back to Lima via the Rio
Rimac valley. The hunt was for several
Bostryx species, but we were only partly
successful. Species like B. solutus and
B. multiconspectus were difficult to find
given the time available.
The second trip was to northern Peru, via Huaráz, up to the area of Chilete. We were able to obtain several Bostryx, Drymaeus, Neopetraeus and Scutalus species. On top of being malacologically successful, it was great to have the ‘Andean experience’ again. I really had a big, big time!
Thanks to my Peruvian companions Valentín Mogollón, Edgar Meza and Pedro Romero. And to Eduardo who drove us quickly and safely through the crazy Peruvian traffic.
In coming posts I will highlight some of the species collected.
The second trip was to northern Peru, via Huaráz, up to the area of Chilete. We were able to obtain several Bostryx, Drymaeus, Neopetraeus and Scutalus species. On top of being malacologically successful, it was great to have the ‘Andean experience’ again. I really had a big, big time!
Thanks to my Peruvian companions Valentín Mogollón, Edgar Meza and Pedro Romero. And to Eduardo who drove us quickly and safely through the crazy Peruvian traffic.
In coming posts I will highlight some of the species collected.
A snail with a long tail
24-03-2010 16:02
In Holland we have the saying “That mouse will have a
long tail...”, denoting that some consequences may
follow. In the context of this blog I prefer to
switch the mouse for a snail. But the consequences
remain.
What happened?
When I arrived on the airport of Tucumán, thunderstorms just were hitting the city. Everybody daring to be out under the sky was soaked within the minute. There was even a total “black-out” at the airport, when the whole plane was waiting at the bagage claim.
Anyway, Eugenia Salas was kind enough to pick me up at the airport. However, when she drove down to the city we had to pass some low areas where the streets had become rivers instead. She drove for ca. 10 minutes through the water and we made it safely to the place where I would stay during my visit. However, when I unpacked my stuff I realized that my laptop could have become wet. I opened it up, and after showing some wildly colourful screens it turned black and stayed that way.
No laptop, no data, no possibility to update my blog and photo stream.
Today I picked up my laptop from the repair shop. All I can say is: I hope to catch up a.s.a.p.
PS: Thanks to Gabriela Cuezzo for putting an old Windows machine at my disposal. That saved me from making notes during my visit the old-fashioned way, with pencil and paper.
What happened?
When I arrived on the airport of Tucumán, thunderstorms just were hitting the city. Everybody daring to be out under the sky was soaked within the minute. There was even a total “black-out” at the airport, when the whole plane was waiting at the bagage claim.
Anyway, Eugenia Salas was kind enough to pick me up at the airport. However, when she drove down to the city we had to pass some low areas where the streets had become rivers instead. She drove for ca. 10 minutes through the water and we made it safely to the place where I would stay during my visit. However, when I unpacked my stuff I realized that my laptop could have become wet. I opened it up, and after showing some wildly colourful screens it turned black and stayed that way.
No laptop, no data, no possibility to update my blog and photo stream.
Today I picked up my laptop from the repair shop. All I can say is: I hope to catch up a.s.a.p.
PS: Thanks to Gabriela Cuezzo for putting an old Windows machine at my disposal. That saved me from making notes during my visit the old-fashioned way, with pencil and paper.