Plekocheilus
Photo of the day (106): Plekocheilus
23-08-2010 09:11
Biodiversity sites are
popping up. And snails get interest too on these
sites, apart from the ‘usual suspects, like mammals,
birds, herps and plants.
This weekend I discovered the site of the Bigal River Conservation Project in northeastern Ecuador. This area (only 10 km2) is located near the vulcano Sumaco, on the border of Prov. Napo and Orellana.
The snail pictured here is not fully-grown, but undoubtedly a Plekocheilus.
This weekend I discovered the site of the Bigal River Conservation Project in northeastern Ecuador. This area (only 10 km2) is located near the vulcano Sumaco, on the border of Prov. Napo and Orellana.
The snail pictured here is not fully-grown, but undoubtedly a Plekocheilus.
Orthalicid radulae (8): Plekocheilus
22-06-2010 14:15
To continue
this
series,
this time a species from Colombia, Cundinamarca,
near Mosquera (RMNH): Plekocheilus (Aeropictus)
delicatus (Pilsbry, 1935). The radula
formula is C + L/1 + M/70.
Shown clockwise, from upper left: overview of part of radula, central part, marginals 5-9 resp. 48-63.
Shown clockwise, from upper left: overview of part of radula, central part, marginals 5-9 resp. 48-63.
Photo of the day (98): Plekocheilus
09-06-2010 10:54
Last week Adrián
González also sent these pictures. They show a
species which I tentatively identify as
Plekocheilus
(Aeropictus) tenuissimus Weyrauch, 1967. The specimen was
collected near El Laurel.
Puzzling with shells and geography
14-06-2010 13:45
For a paper in
preparation about Colombian species, Francisco
Borrero and I have been puzzling with some
localities. Earlier, I posted on this topic
here.
This time the hunt was for the type locality
of Plekocheilus
taquinensis (Pfeiffer, 1855), a place called
Taquina which is not in the gazetteers we consulted.
All we knew was that Taquina is located somewhere in the Sierra Nevada de Santa Marta, at around 2700 m. We also knew that the British conchologist Tom Pain collected the species “in the vicinity of the type locality” in 1939 (Crowley & Pain, 1958).
The solution came when we found two sources with the help of other disciplines. The first was Todd & Carriker’s 1922 paper on birds of the area; they have a map which shows several Indian villages in the north-eastern part of the Sierra. This was confirmed by a geographical study by Simmons (1981).
Another puzzling species was Plekocheilus couturesi (Ancey, 1900), described from Bolivia. The type has recently been figured by Wood & Gallichan (2008). Since the shell was unlike the few Bolivian Plekocheilus species, but more resembled some forms from Colombia, I decided to ask for additional pictures to the National Museum of Wales. When I received these photographs, it appeared that the sculpture of the shells was peculiar and similar to that on shells we have from the Tatamá National Park in the Riseralda/Chocó area. Which led us to believe that this taxon was actually a Colombian and not a Bolivian species.
We first tried to trace the source of the shell, collected by G. Coutures. However, we couldn’t find any data on this person and his itinerary in South America. Puzzling...
The story became more complicated, when we received pictures of the type material of P. taquinensis, showing that this species has a similar sculpture. Now we had two different sources for the type locality of couturesi, the Sierra Nevada de Santa Marta in the northern part and the Cordillera Occidental in the western part of Colombia. Very puzzling... However, the shell shape of couturesi is slightly dissimilar to the shells of these two localities, which are both at high altitudes (2700-3600 m).
It then occurred to Francisco that “Bolivia” might not refer to a country, but to a locality of the same name. Could we find such a locality at an appropriate elevation? To my surprise, the GNS gazetteer gave 10 places named Bolivia in various departments of Colombia. Then it was only a matter of scoring out, to be left with a single locality that seems the most likely candidate. It is in the western part of Tolima on the border with Valle del Cauca.
Puzzling with shells and geography, this time with a happy ending...
References:
Crowley, T.E. & Pain, T., 1958. On an unfigured species of Plekocheilus (Eurytus). - Journal of Conchology 24: 234-235.
Simmons, F.A.A., 1981. On the Sierra Nevada de Santa Marta and its watershed. - Proceedings of the Royal Geographical Society 12: 717-718.
Todd, W.E.C. & Carriker, M.A. jr, 1922. The birds of the Santa Marta region of Colombia: A study in altitudinal distribution. - Annals of the Carnegie Museum 14: 3-583.
Wood, H. & Gallichan, J., 2008. The new molluscan names of César-Marie-Felix Ancey, including illustrated type material from the National Museum of Wales. Studies in Biodiversity and Systematics of Terrestrial Organisms from the National Museum of Wales. Biotir Reports 3: i-vi, 1-162.
All we knew was that Taquina is located somewhere in the Sierra Nevada de Santa Marta, at around 2700 m. We also knew that the British conchologist Tom Pain collected the species “in the vicinity of the type locality” in 1939 (Crowley & Pain, 1958).
The solution came when we found two sources with the help of other disciplines. The first was Todd & Carriker’s 1922 paper on birds of the area; they have a map which shows several Indian villages in the north-eastern part of the Sierra. This was confirmed by a geographical study by Simmons (1981).
Another puzzling species was Plekocheilus couturesi (Ancey, 1900), described from Bolivia. The type has recently been figured by Wood & Gallichan (2008). Since the shell was unlike the few Bolivian Plekocheilus species, but more resembled some forms from Colombia, I decided to ask for additional pictures to the National Museum of Wales. When I received these photographs, it appeared that the sculpture of the shells was peculiar and similar to that on shells we have from the Tatamá National Park in the Riseralda/Chocó area. Which led us to believe that this taxon was actually a Colombian and not a Bolivian species.
We first tried to trace the source of the shell, collected by G. Coutures. However, we couldn’t find any data on this person and his itinerary in South America. Puzzling...
The story became more complicated, when we received pictures of the type material of P. taquinensis, showing that this species has a similar sculpture. Now we had two different sources for the type locality of couturesi, the Sierra Nevada de Santa Marta in the northern part and the Cordillera Occidental in the western part of Colombia. Very puzzling... However, the shell shape of couturesi is slightly dissimilar to the shells of these two localities, which are both at high altitudes (2700-3600 m).
It then occurred to Francisco that “Bolivia” might not refer to a country, but to a locality of the same name. Could we find such a locality at an appropriate elevation? To my surprise, the GNS gazetteer gave 10 places named Bolivia in various departments of Colombia. Then it was only a matter of scoring out, to be left with a single locality that seems the most likely candidate. It is in the western part of Tolima on the border with Valle del Cauca.
Puzzling with shells and geography, this time with a happy ending...
References:
Crowley, T.E. & Pain, T., 1958. On an unfigured species of Plekocheilus (Eurytus). - Journal of Conchology 24: 234-235.
Simmons, F.A.A., 1981. On the Sierra Nevada de Santa Marta and its watershed. - Proceedings of the Royal Geographical Society 12: 717-718.
Todd, W.E.C. & Carriker, M.A. jr, 1922. The birds of the Santa Marta region of Colombia: A study in altitudinal distribution. - Annals of the Carnegie Museum 14: 3-583.
Wood, H. & Gallichan, J., 2008. The new molluscan names of César-Marie-Felix Ancey, including illustrated type material from the National Museum of Wales. Studies in Biodiversity and Systematics of Terrestrial Organisms from the National Museum of Wales. Biotir Reports 3: i-vi, 1-162.
Photo of the day (93): Plekocheilus
26-04-2010 16:29
The photo of the day is
today not of a live snail. Instead it is an
interesting find from the Leiden collection that I
recently did.
This shell was collected by Otto Huber in Venezuela, Edo. Bolívar, Sierra de Guanay, Cedenho. This locality is at 1670 m and thus in highland according to the definition by Huber (1995).
The shell definitely belongs to Plekocheilus (Eurytus). However, the bleached stage of this specimen doesn’t allow me to be conclusive about its name. I have compared it to several other species and it is different to anything else. But its condition is too bad to say more than Plekocheilus (Eurytus) n. sp.
It is an addition to my papers on the malacofauna of southern Venezuela (Breure, 2009; Breure & Schlögl, 2010).
References:
Breure, A.S.H., 2009. New Orthalicidae (Mollusca, Gastropoda) from Venezuelan Guayana: unravelling secrets from the Lost World. - Zootaxa 2065: 26-50.
Breure, A.S.H. & Schlögl, J., 2010. Additional notes on Orthalicidae from the Chimantá massif, Venezuelan Guayana, with descriptions of new species of Plekocheilus Guilding, 1828 (Mollusca: Gastropoda). - Zootaxa 2416: 51-60.
Huber, O., 1995. Geographical and physical features. In: Berry, P.E., Holst, B.K. & Yatskievych, K. (eds.), Flora of the Venezuelan Guayana. I. Introduction: 63-95. Missouri Botanical Garden Press, St. Louis.
This shell was collected by Otto Huber in Venezuela, Edo. Bolívar, Sierra de Guanay, Cedenho. This locality is at 1670 m and thus in highland according to the definition by Huber (1995).
The shell definitely belongs to Plekocheilus (Eurytus). However, the bleached stage of this specimen doesn’t allow me to be conclusive about its name. I have compared it to several other species and it is different to anything else. But its condition is too bad to say more than Plekocheilus (Eurytus) n. sp.
It is an addition to my papers on the malacofauna of southern Venezuela (Breure, 2009; Breure & Schlögl, 2010).
References:
Breure, A.S.H., 2009. New Orthalicidae (Mollusca, Gastropoda) from Venezuelan Guayana: unravelling secrets from the Lost World. - Zootaxa 2065: 26-50.
Breure, A.S.H. & Schlögl, J., 2010. Additional notes on Orthalicidae from the Chimantá massif, Venezuelan Guayana, with descriptions of new species of Plekocheilus Guilding, 1828 (Mollusca: Gastropoda). - Zootaxa 2416: 51-60.
Huber, O., 1995. Geographical and physical features. In: Berry, P.E., Holst, B.K. & Yatskievych, K. (eds.), Flora of the Venezuelan Guayana. I. Introduction: 63-95. Missouri Botanical Garden Press, St. Louis.
Photo of the day (91): Plekocheilus
12-04-2010 21:19
This is a picture of
what appears like a subadult Plekocheilus
(Eurytus) cf. taylorianus
(Reeve, 1849).
The picture was taken by Adrián González in Prov. Imbabura, Chontal Alto region, in cloud forest.
The picture was taken by Adrián González in Prov. Imbabura, Chontal Alto region, in cloud forest.
New paper published
01-04-2010 19:33
Photo of the day (72): Plekocheilus
22-10-2009 07:51
Another species that
Grace Montalván collected near Río Arabela in
northern Peru is Plekocheilus (Eurytus)
superstriatus (Sowerby, 1899). Although the field
of depth of these photographs is not excellent, I’m
happy to show them here, as these are also the first
pictures showing the living animal.
When you compare it to the pictures from yesterday, you will see a marked difference in the body colour. Unfortunately this snail too didn’t survive very long after being collected.
Thanks Grace!
When you compare it to the pictures from yesterday, you will see a marked difference in the body colour. Unfortunately this snail too didn’t survive very long after being collected.
Thanks Grace!
Photo of the day (71): Plekocheilus
21-10-2009 20:35
Today some pictures of
a wide-spread species, Plekocheilus (Eurytus)
floccosus (Spix, 1827). As far as I know,
these are the first pictures showing the living
animal. The specimens were found in Peru, near Río
Arabela.
Unfortunately, the snails died after being collected by Grace Montalván, who also made the photographs.
Unfortunately, the snails died after being collected by Grace Montalván, who also made the photographs.
The death of a snail
05-09-2009 21:43
The second of my living
Plekocheilus
snails became totally inactive and didn’t react any
more to gentle probing. Before the decay really
started, I decided to kill the animal off. Ah, life
can be very cruel... Who wants to end up in a science
laboratory?
The interesting thing is to see how the animal discoloured after I put it in alcohol 70%. Its beige coloured body when alive, turned grayish while the alcohol showed a yellowish hue. Apparently the body colour dissolved, but I can’t remember to have seen that before when preserving snails; a quick search in Scholar didn’t return any useful hits. Something to sort out later.
As a consequence this is also the end of the living type specimen story. R.I.P. Hugo and Marisabel.
The interesting thing is to see how the animal discoloured after I put it in alcohol 70%. Its beige coloured body when alive, turned grayish while the alcohol showed a yellowish hue. Apparently the body colour dissolved, but I can’t remember to have seen that before when preserving snails; a quick search in Scholar didn’t return any useful hits. Something to sort out later.
As a consequence this is also the end of the living type specimen story. R.I.P. Hugo and Marisabel.
Tepui snails again
16-06-2009 20:37
More on
snails and
bromeliads.
Today some pictures that I received from Charles
Brewer-Carias, here pictured amidst
Brocchinia
on Churí-tepui. BTW: stunning landscape...
He found snails inside the hollow axes of these bromeliads, where they shelter during the day.
As they feed on the dead leafs during the evening and at night (! again, see previous post), it was assumed at first sight that this pattern on those dead leafs were the gnawing marks of radulas from these snails.
However, I found it hard to imagine that the snails would move so ‘uncontrolled’ over these leafs to make such a pattern. And if you really look in detail on the green leaf at the right-hand corner, you will see a similar pattern shining through the leaf. My conclusion is thus that the snails may feed on e.g. algae but are not causing this pattern on the leafs.
Credits to Kiko Mayoral and Javier Mesa for the photographs and to Charles for sharing the pictures.
He found snails inside the hollow axes of these bromeliads, where they shelter during the day.
As they feed on the dead leafs during the evening and at night (! again, see previous post), it was assumed at first sight that this pattern on those dead leafs were the gnawing marks of radulas from these snails.
However, I found it hard to imagine that the snails would move so ‘uncontrolled’ over these leafs to make such a pattern. And if you really look in detail on the green leaf at the right-hand corner, you will see a similar pattern shining through the leaf. My conclusion is thus that the snails may feed on e.g. algae but are not causing this pattern on the leafs.
Credits to Kiko Mayoral and Javier Mesa for the photographs and to Charles for sharing the pictures.
Snails and bromeliads
10-06-2009 22:04
Charles Brewer-carias kindly sent me some
observations on a
Plekocheilus
species that he found in southern Venezuela. The
species was found inside the rosettes of
Brocchinia
leafs, where the snails hide during day-time. In the
evening they become active and start feeding on the
dead leaves of the plants.
The fact that the fresh leaves are not touched may be explained by the hard and waxed surface of these leaves. Probably the decaying leaves are soft enough to be eaten by the snails.
The fact that the fresh leaves are not touched may be explained by the hard and waxed surface of these leaves. Probably the decaying leaves are soft enough to be eaten by the snails.
Rearing snails in the lab
18-05-2009 16:41
My snails are still alive (previously reported
on
here,
here
and
here).
Using a glass vial and lid, the bottom is now covered
with paper and I added a twig of
Laurus
nobilis
to provide them with a place to shelter, just changed
to today to
Cornus
sp. found in the Naturalis garden. Yes, wo do have a
museum ‘garden’..., but do not expect beautiful
flowers there, more ‘semi-domesticated nature’.
So far I fed them slices of cucumber (about 1 cm thick), of which they predominantly eat the skin. Sometimes I find the slices partly eaten away.
Curious about what others have tried, I found an interesting paper by Krull (2006) on tropical arboreal snails. He describes the rearing of Liguus and Pleurodonte species under lab conditions. Both species occur in Florida and especially the mentioning of Liguus is interesting, as it is related to my snails.
The biology of Liguus is rather well-known (details in Krull, 2006) and seems to me to be quite distinct from the Plekocheilus living on tepuis in a very humid climate. However, they both are living on the vegetation and are no ground dwellers.
The paper describes the application of an artifical food that was developed especially for Liguus. I suppose it may suit other (non-carnivorous) land-snails too. The basic ingredients are broccoli (calcium!), beer, buttermilk, a chewable multi-vitamin and calcium carbonate, with oat flour added for consistency. That already must be power food! Other ingredients sometimes added to this menu were honey, yoghurt, bananas, carrots and algae-formulated fish food. His lab must be truly a gourmet restaurant... All ingredients were blended and mold spores were added; then the resulting mixture was sprayed on the glass wall of the tanks that Liguus was kept.
Not having kitchen facilities in my lab, I have chosen not to blend the ingredients but feed my snails piece-meal. Whatever happens, they will end up in ethanol, one day...
Pete Krull added in emails that “the food mixture works well for any species that ‘scrapes’ food from tree limbs, rocks or other hard substrate”. His experience extends to Orthalicus, Pleurodonte and Otala species. The latter usually eat the green parts of vegetation, but they thrive also on the food mixture.
Liguus (now a ‘species of special concern’ in Florida and no longer reared) and Orthalicus require sunlight or artificial UV light to grow, mate and multiply.
Reference:
Krull, P., 2006. Rearing tropical arboreal snails in the laboratory. - Tentacle 14: 3-5.
So far I fed them slices of cucumber (about 1 cm thick), of which they predominantly eat the skin. Sometimes I find the slices partly eaten away.
Curious about what others have tried, I found an interesting paper by Krull (2006) on tropical arboreal snails. He describes the rearing of Liguus and Pleurodonte species under lab conditions. Both species occur in Florida and especially the mentioning of Liguus is interesting, as it is related to my snails.
The biology of Liguus is rather well-known (details in Krull, 2006) and seems to me to be quite distinct from the Plekocheilus living on tepuis in a very humid climate. However, they both are living on the vegetation and are no ground dwellers.
The paper describes the application of an artifical food that was developed especially for Liguus. I suppose it may suit other (non-carnivorous) land-snails too. The basic ingredients are broccoli (calcium!), beer, buttermilk, a chewable multi-vitamin and calcium carbonate, with oat flour added for consistency. That already must be power food! Other ingredients sometimes added to this menu were honey, yoghurt, bananas, carrots and algae-formulated fish food. His lab must be truly a gourmet restaurant... All ingredients were blended and mold spores were added; then the resulting mixture was sprayed on the glass wall of the tanks that Liguus was kept.
Not having kitchen facilities in my lab, I have chosen not to blend the ingredients but feed my snails piece-meal. Whatever happens, they will end up in ethanol, one day...
Pete Krull added in emails that “the food mixture works well for any species that ‘scrapes’ food from tree limbs, rocks or other hard substrate”. His experience extends to Orthalicus, Pleurodonte and Otala species. The latter usually eat the green parts of vegetation, but they thrive also on the food mixture.
Liguus (now a ‘species of special concern’ in Florida and no longer reared) and Orthalicus require sunlight or artificial UV light to grow, mate and multiply.
Reference:
Krull, P., 2006. Rearing tropical arboreal snails in the laboratory. - Tentacle 14: 3-5.
Living snails (3)
22-04-2009 08:10
A continuation from this
post...
Three videos of the snails crawling around. Two of Hugo on my desk, from different angles. One inside their ‘home’, where you can see the shape of the foot and the movement viewed through the glass.
After a suggestion from one of the visitors of the NMV-meeting, I have given Hugo and Marisabel a new home. More spacious. And greener. Should be a real improvement, don’t you think?
Will keep you posted...
Three videos of the snails crawling around. Two of Hugo on my desk, from different angles. One inside their ‘home’, where you can see the shape of the foot and the movement viewed through the glass.
After a suggestion from one of the visitors of the NMV-meeting, I have given Hugo and Marisabel a new home. More spacious. And greener. Should be a real improvement, don’t you think?
Will keep you posted...
Living snails (2)
17-04-2009 18:10
Continuing my
post
on the tepui snails...
My living snails have been transferred to Naturalis. Here ‘Hugo’ and ‘Marisabel’ are sitting on my desk.
Looking at the colour of the animals, it is remarkable to see the variation. One is uniformly beige (slightly darker near the foot), the other has a darker dorsal stripe on the body and the ocular tentacles with darker tips.
Meanwhile I have come to the conclusion that they belong to a new taxon. Just don’t know yet if they are subspecifically or specifically distinct from Plekocheilus fulminans alticola Haas, 1955, occurring elsewhere in the area. The species in this genus show a very interesting mix of characters at different localities. Although seemingly nearby, the distances are actually rather large (10+ km). I will elaborate this in a new paper.
To be continued...
My living snails have been transferred to Naturalis. Here ‘Hugo’ and ‘Marisabel’ are sitting on my desk.
Looking at the colour of the animals, it is remarkable to see the variation. One is uniformly beige (slightly darker near the foot), the other has a darker dorsal stripe on the body and the ocular tentacles with darker tips.
Meanwhile I have come to the conclusion that they belong to a new taxon. Just don’t know yet if they are subspecifically or specifically distinct from Plekocheilus fulminans alticola Haas, 1955, occurring elsewhere in the area. The species in this genus show a very interesting mix of characters at different localities. Although seemingly nearby, the distances are actually rather large (10+ km). I will elaborate this in a new paper.
To be continued...
Living snails
13-04-2009 22:04
Today a long-awaited package arrived. Or rather, I
had to pick it up myself in Assen (more than 5 hours
by train, both ways). It contained ‘scientific
material. no commercial value’, viz. shells and
snails. My newest pets... living
Plekocheilus.
Since the laboratories were closed today, they will
spent one night at my home.
Alas, one of the three didn’t survive the trip. I have nicknamed her ‘Nancy’. The other two appeared to be alive. One of them has a number of spiral stripes on the last whorl; I have named it ‘Hugo’. The other has one, narrow spiral band but is otherwise elegantly dark brownish; I have named it ‘Marisabel’.
Hugo and Marisabel. Just two names, who happen to occur in Latin America ;-)
Hugo is immediately active upon opening the package. I put him on the cucumber I had bought especially for my snails and seems to love it.
Marisabel was withdrawn into the shell. First I fear that she is dead too. After diner I see that she is awoken. I quickly start to make some pictures and videos.
More on them later.
Alas, one of the three didn’t survive the trip. I have nicknamed her ‘Nancy’. The other two appeared to be alive. One of them has a number of spiral stripes on the last whorl; I have named it ‘Hugo’. The other has one, narrow spiral band but is otherwise elegantly dark brownish; I have named it ‘Marisabel’.
Hugo and Marisabel. Just two names, who happen to occur in Latin America ;-)
Hugo is immediately active upon opening the package. I put him on the cucumber I had bought especially for my snails and seems to love it.
Marisabel was withdrawn into the shell. First I fear that she is dead too. After diner I see that she is awoken. I quickly start to make some pictures and videos.
More on them later.
New taxa (14): Plekocheilus
10-04-2009 09:27
Finally, there is a peculiar species from the eastern
tepui region,
Plekocheilus
(Eurytus)
sophiae
from Yuraní-tepui.
The holotype is also in the Florida museum, UF 24413. This is the single specimen currently known, but since it is so peculiar I ventured to describe it as a new species.
The holotype is also in the Florida museum, UF 24413. This is the single specimen currently known, but since it is so peculiar I ventured to describe it as a new species.
New taxa (13): Plekocheilus
09-04-2009 08:26
Two more new species, originating from the same Cerro
de la Neblina expedition mentioned
here.
It are congeneric, sympatric species of
Plekocheilus
(Eurytus).
The first is P. (E.) huberi, named after Otto Huber who as a botanist has devoted his career to the tepui area. Holotype UF 284764.
The second is P. (E.) nebulosus. Holotype UF 284723. It is from the Cerro de la Neblina massif, which lends its name to this taxon.
The first is P. (E.) huberi, named after Otto Huber who as a botanist has devoted his career to the tepui area. Holotype UF 284764.
The second is P. (E.) nebulosus. Holotype UF 284723. It is from the Cerro de la Neblina massif, which lends its name to this taxon.
New taxa (12): Plekocheilus
08-04-2009 19:10
A second new species from Venezuela Guayana is
Plekocheilus
(Eurytus)
tepuiensis.
The holotype, and only specimen so far known, is a
subadult. However, the colouration and the sculpture
of the last whorl sets it apart from all taxa
previously described.
It was collected on Cerro Yapacana. The holotype is in the Leiden museum, RMNH 112031.
It was collected on Cerro Yapacana. The holotype is in the Leiden museum, RMNH 112031.
A new paper
06-04-2009 17:37
Today my paper on a revision of the Orthalicidae from
Venezuelan Guayana was published in
Zootaxa.
Later this week more on it.
Later this week more on it.
Photo of the day (41): Plekocheilus
23-02-2009 20:38
Another photo, sent by Jan Schlogl, of some live
specimens of
Plekocheilus
(P.)
fulminans
alticola
Haas, 1955.
They were also spotted on the Chimantá massif in Venezuelan Guayana. It is really exciting to see that snails are not so extremely rare in that area as previously thought. Provided that you are focussed on them.
They were also spotted on the Chimantá massif in Venezuelan Guayana. It is really exciting to see that snails are not so extremely rare in that area as previously thought. Provided that you are focussed on them.
Photo of the day (40): Plekocheilus
21-02-2009 16:11
Interestingly, the Slovakian geological-speleological
team that visited Venezuelan Guayana the past weeks,
found quite a number of snails. I reported on their
preliminary findings
here,
but today I got more information on two species that
were found on the Chimantá massif.
The first picture is from a juvenile specimen of Plekocheilus (Eurytus) juliani Haas, 1955. The picture shows the characteristic zig-zag striping and the light body colour, darker on the upper part. This species lives on bromeliads (Brocchinia sp.) that were found in canyons more than 100 m deep.
The second species is P. (E.) mundiperditi Haas, 1955. It has a dark-brown shell and also the animal is darker coloured throughout. This species was only encountered on top of the plateau, associated with low Bonnetia trees.
To me it seems that these species each occur in a narrow ecological niche, possibly with their own host plants.
Thanks to Jan Schlogl, who kindly sent me the pictures.
The first picture is from a juvenile specimen of Plekocheilus (Eurytus) juliani Haas, 1955. The picture shows the characteristic zig-zag striping and the light body colour, darker on the upper part. This species lives on bromeliads (Brocchinia sp.) that were found in canyons more than 100 m deep.
The second species is P. (E.) mundiperditi Haas, 1955. It has a dark-brown shell and also the animal is darker coloured throughout. This species was only encountered on top of the plateau, associated with low Bonnetia trees.
To me it seems that these species each occur in a narrow ecological niche, possibly with their own host plants.
Thanks to Jan Schlogl, who kindly sent me the pictures.
Prey of a bird and a bird of prey?
06-02-2009 17:19
At the moment some Slovak and Czech geologists are
out in the field in Venezuelan Guayana. Their main
objective is further research on caves, but luckily
they have informed themselves on what they might find
in malacological terms.
As an interim report I received today some news about observations on Plekocheilus. They found shells “locally common, even inside under bird nests”.
It seems that a bird species (not yet sure which one) is sampling these snails on the tepuis and bring them to their nests inside the cave, where they feed them to their young. A nice, big meal of proteins! Broken shells drop down on the cave floor.
An intriguing story on which I hope to get more details later...
Thanks Jozef, for the information!
As an interim report I received today some news about observations on Plekocheilus. They found shells “locally common, even inside under bird nests”.
It seems that a bird species (not yet sure which one) is sampling these snails on the tepuis and bring them to their nests inside the cave, where they feed them to their young. A nice, big meal of proteins! Broken shells drop down on the cave floor.
An intriguing story on which I hope to get more details later...
Thanks Jozef, for the information!
Sneak preview
16-01-2009 09:39
Yes, I’m also one of them... One of the “happy many”
that will be part of ‘Darwin-mania’ next month.
I mentioned it before, but Naturalis will be the host for an international congress devoted on “Evolutionary islands”, 12 and 13 February. Part of the game for me was to make a poster. Having done that never before, it was a happy coincidence that the topic presented itself: radiation in land snails on Venezuelan tepui islands.
The making of... was somewhat like preparing a presentation. What is the essential message that I want to bring across? What can illustrate it best? But here also is important how to do that in a very concise manner. Focussing on essentials and how to select the best pictures to illustrate them. You may judge if I succeeded or not.
While you have still two weeks for registering for the congress, I just wanted to give you a sneak preview of what may be expected. There will be more than 30 other posters and 200 participants are expected.
A special word of thanks to my colleague Jeremy Miller for his kind and invaluable help during the making of this poster.
I mentioned it before, but Naturalis will be the host for an international congress devoted on “Evolutionary islands”, 12 and 13 February. Part of the game for me was to make a poster. Having done that never before, it was a happy coincidence that the topic presented itself: radiation in land snails on Venezuelan tepui islands.
The making of... was somewhat like preparing a presentation. What is the essential message that I want to bring across? What can illustrate it best? But here also is important how to do that in a very concise manner. Focussing on essentials and how to select the best pictures to illustrate them. You may judge if I succeeded or not.
While you have still two weeks for registering for the congress, I just wanted to give you a sneak preview of what may be expected. There will be more than 30 other posters and 200 participants are expected.
A special word of thanks to my colleague Jeremy Miller for his kind and invaluable help during the making of this poster.
Photo of the day (32): Plekocheilus
08-01-2009 22:15
Another picture from the suite that David Robinson
sent me. It is
Plekocheilus
(Eudolichotis)
glaber
(Gmelin, 1791). It was collected by him on Trinidad.
The Eudolichotis group is very distinct, but the different taxa show a lot of plasticity. A future revision may benefit from pictures as this, showing the colour of the animal.
The Eudolichotis group is very distinct, but the different taxa show a lot of plasticity. A future revision may benefit from pictures as this, showing the colour of the animal.
Photo of the day (18): Plekocheilus
27-08-2008 22:31
Roy McDiarmid, a herpetologist from the Smitsonian
Institution, has been kind enough to send me some
pictures of Plekocheilus species from the Cerro de la
Neblina on the border of Venezuela and Brazil. He
lead expeditions to that area from 1983-1987 and
supplied valuable information from his archives.
The snail depicted here is P. (Eurytus) juliani Haas, 1955, described from the Chimantá massif in the eastern part of the Guayana Highlands.
The snail depicted here is P. (Eurytus) juliani Haas, 1955, described from the Chimantá massif in the eastern part of the Guayana Highlands.
Photo of the day (2): Plekocheilus
28-03-2008 18:13
Today I even have two new photographs (and more
coming), thanks to the courtesy of Toine Cleef who
searched through his old slides from field work.
This time a rather common species from the Bogotá region, Plekocheilus (Aeropictus) succinoides (Petit, 1840), taken at Páramo de la Rusia, Colombia.
This time a rather common species from the Bogotá region, Plekocheilus (Aeropictus) succinoides (Petit, 1840), taken at Páramo de la Rusia, Colombia.
You win some and you lose some
28-01-2008 09:05
This weekend I uncovered my archive from the dust.
When I made my career switch in the early '80s I
didn't want to throw everything away (using the motto
"when you keep something, you have something").
Subsequently when we moved in 1992 everything was put
in a box and stored in a dark place in the house.
When my malacological research interest regained momentum some years ago, I could quickly find my literature card-index system (it still comes in very handy to locate reprints) but not my notes, although I knew that there was probably something. Last week a box full of notes turned up. Not as much as I had expected, but still with some very valuable notes, drawings (several unpublished) and photographs. Nowadays we don't fancy these B/W pictures anymore, but 30 years ago it was the best we had (and the only thing acceptable for publication!). Still, imagine how it would look like in full-colour....
Plekocheilus succineoides (Petit). Photo's: Toine Cleef
When my malacological research interest regained momentum some years ago, I could quickly find my literature card-index system (it still comes in very handy to locate reprints) but not my notes, although I knew that there was probably something. Last week a box full of notes turned up. Not as much as I had expected, but still with some very valuable notes, drawings (several unpublished) and photographs. Nowadays we don't fancy these B/W pictures anymore, but 30 years ago it was the best we had (and the only thing acceptable for publication!). Still, imagine how it would look like in full-colour....
Plekocheilus succineoides (Petit). Photo's: Toine Cleef
Colombian Plekocheilus
06-12-2007 21:04
Working on Colombian Orthalicoidea, I inventarized
all data on the genus Plekocheilus so far available
to me. It's quite a list, with 40 taxa of which 4 are
doubtful occurrences in Colombia. Of the remaining 36
taxa, there are 8 that are only known by the type
material. For the shortlist of 28 taxa I found 75
localities in museums (collections and databases) and
literature that could be georeferenced.
A first rough analysis in Maxent revealed a pattern somewhat similar to that I found in Ecuador, however it needs more analysis to find out a realistic distribution. The number of occurrences is higher in Colombia, at least allowing for some analysis on species level.
Anyway, my first impression is that also in this country part of it is seriously undersampled, not only for this genus but for the family as a whole.
A first rough analysis in Maxent revealed a pattern somewhat similar to that I found in Ecuador, however it needs more analysis to find out a realistic distribution. The number of occurrences is higher in Colombia, at least allowing for some analysis on species level.
Anyway, my first impression is that also in this country part of it is seriously undersampled, not only for this genus but for the family as a whole.
Nearing submission
18-11-2007 20:24
The checklist of
Ecuadorian Orthalicoidea is nearing its final stage.
At least for now. Two reviewers have kindly provided
their comments, so I put the manuscript in the format
prescribed by the journal (Zootaxa) and announced my
intention to one of the editors.
The localities are plotted here (blue ones sampled after 1950, yellow ones older).
Francisco Borrero, who was so kind to review the manuscript, also sent me some pictures which he received from contacts in southern Ecuador. The following picture is identified by me as Plekocheilus (Eurytus) roseolabrum (E.A. Smith, 1877), a rare species that has not been found after its original description.
The localities are plotted here (blue ones sampled after 1950, yellow ones older).
Francisco Borrero, who was so kind to review the manuscript, also sent me some pictures which he received from contacts in southern Ecuador. The following picture is identified by me as Plekocheilus (Eurytus) roseolabrum (E.A. Smith, 1877), a rare species that has not been found after its original description.
Patience is a virtue
28-06-2007 08:52
Being dependence on the
co-operation of others is a burden. That sprang to
mind when I discussed the progress (none) in my
phylogenetic work with a collegue at Naturalis. It's
frustrating, but what can one do about it, when there
are no facilities at hand? The virtue of having
patience is certainly appilcable here, but I don't
like the role of lame duck. I know it's a matter of
priorities (also on my side), but let's see what new
opportunities for progress the WCM next month might
offer.
Meanwhile, I'm making progress on the Venezuelan Plekocheilus. Started to describe a new species from the southern part of the country. Unfortunately, there is only one (adult) specimen. As it originates from one of the tepuis, it will be difficult to collect additional ones. I should contact Valentí Rull to hear about the procedures for collecting in that area. Perhaps there is a way to do some field work...perhaps.... Hmm, tantalizing idea....
Meanwhile, I'm making progress on the Venezuelan Plekocheilus. Started to describe a new species from the southern part of the country. Unfortunately, there is only one (adult) specimen. As it originates from one of the tepuis, it will be difficult to collect additional ones. I should contact Valentí Rull to hear about the procedures for collecting in that area. Perhaps there is a way to do some field work...perhaps.... Hmm, tantalizing idea....