Venezuela
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.
New paper published
01-04-2010 19:33
New books
04-02-2010 07:12
Three new books have
been published or announced, that might be
interesting for those interested in the Cuban
malacofauna and the geology and biogeography of
Amazonia.
The first is a book by Espinosa & Ortea, published by Spartacus Foundation and the Cuban Zoological Society. I haven’t seen it myself yet, but I found the following announcement of a book dealer:
This is a gorgeous book and I think that the photography here is possibly the best live animal photography that I have seen in all of my other titles. It is simply amazing and the book is also an amazing work. Its focus is to introduce us to the numerous families of terrestrial mollusks that live in Cuba. Most of the shells are show alive in their natural habitat in extreme close up. The text (in Spanish) gives us an overview of the shell family, its habitat , the characteristic of these shells and a lot of background information. My Spanish is not good enough to understand the more technical details that the authors have written but from what I can understand it is a carefully written and thoroughly researched book. The authors and the photographer are prominent workers in the scientific field and it is a shame that their names and their works are not well know in the USA. The last section of their book is a check list of 1393 species of land-shells found in Cuba.
From what I saw of the pictures in the announcement, some will be the same as those used in the book of González. They partly share the same photographer. Hopefully, they have corrected all the errors they made in the previous version of their checklist (Espinosa & Ortega, 1999). But a judgement should be postponed till I have actually seen the book.
The second book on Cuban terrestrial snails is, if possible, even more obscure and curious. It is a publication based on an unfinished manuscript of Torre & Bartsch. There is a quite complication story to this book (which is beyond the scope of this blog), that has been published as a tribute to Carlos de la Torre y Huerta (1858-1950) in 2008. From what I know, several new species are described in this book, casting an interesting question on the rules of nomenclature. Are they to be credited to the original authors (as posthume work) or to the editor of this book?
Again, let’s first see this book before making a judgement.
Finally, an impressive book will be published on February 16, entitled “Amazonia: landscape and species evolution. A look into the past”. I had the privilege to have a sneak preview and I can assure you this will be a reference work for those working on the biogeography of northern South America.
This book focuses on geological history as the critical factor in determining the present biodiversity and landscapes of Amazonia. We explore the different driving mechanisms for landscape evolution by reviewing the history of the Amazon Craton, the associated sedimentary basins, and the role of mountain uplift and climate change. Throughout the book we provide an insight into the Meso- and Cenozoic record of Amazonia that was characterized by fluvial and long-lived lake systems and a highly diverse flora and fauna. This fauna includes giants such as the ca. 12 m long caiman Purussaurus, but also a varied fish fauna and fragile molluscs, whilst fossil pollen and spores form relics of ancestral swamps and rainforests.
Finally, we review the molecular datasets of the modern Amazonian rainforest and aquatic ecosystem, and discuss the possible relations between the origin of Amazonian species diversity and the palaeogeographic, palaeoclimatic and palaeoenvironmental evolution of northern South America. The multidisciplinary approach in evaluating the history of Amazonia has resulted in a comprehensive volume that provides novel insights into the evolution of this region and can serve as reference for a variety of scientists working in Amazonia.
The book is written by leading scientists of the Amazonian research community and should be of interest to all students and researchers concerned with the natural history of Amazonia. Potential readers will include geologists, geographers and biologists who wish to understand the evolution of landscapes and biota of this unique region.
I hope to briefly review this book after its publication.
References:
Espinosa, J. & Ortega, J., 2009. Moluscos terrestres de Cuba: 1-191. Spartacus Foundation/Sociedad Cubana de Zoología.
Hoorn C. & Wesselingh, F. (eds.), 2010. Amazonia: landscape and species evolution. A look into the past: 1-447. Wiley-Blackwell.
Torre, C. de la & Bartsch, P., 2008. Los moluscos terrestres Cubanos de la familia Urocoptidae: 1-730 + 1-23. Editoria Científico-Técnica, La Habana/Ruth Casa, Panama.
The first is a book by Espinosa & Ortea, published by Spartacus Foundation and the Cuban Zoological Society. I haven’t seen it myself yet, but I found the following announcement of a book dealer:
This is a gorgeous book and I think that the photography here is possibly the best live animal photography that I have seen in all of my other titles. It is simply amazing and the book is also an amazing work. Its focus is to introduce us to the numerous families of terrestrial mollusks that live in Cuba. Most of the shells are show alive in their natural habitat in extreme close up. The text (in Spanish) gives us an overview of the shell family, its habitat , the characteristic of these shells and a lot of background information. My Spanish is not good enough to understand the more technical details that the authors have written but from what I can understand it is a carefully written and thoroughly researched book. The authors and the photographer are prominent workers in the scientific field and it is a shame that their names and their works are not well know in the USA. The last section of their book is a check list of 1393 species of land-shells found in Cuba.
From what I saw of the pictures in the announcement, some will be the same as those used in the book of González. They partly share the same photographer. Hopefully, they have corrected all the errors they made in the previous version of their checklist (Espinosa & Ortega, 1999). But a judgement should be postponed till I have actually seen the book.
The second book on Cuban terrestrial snails is, if possible, even more obscure and curious. It is a publication based on an unfinished manuscript of Torre & Bartsch. There is a quite complication story to this book (which is beyond the scope of this blog), that has been published as a tribute to Carlos de la Torre y Huerta (1858-1950) in 2008. From what I know, several new species are described in this book, casting an interesting question on the rules of nomenclature. Are they to be credited to the original authors (as posthume work) or to the editor of this book?
Again, let’s first see this book before making a judgement.
Finally, an impressive book will be published on February 16, entitled “Amazonia: landscape and species evolution. A look into the past”. I had the privilege to have a sneak preview and I can assure you this will be a reference work for those working on the biogeography of northern South America.
This book focuses on geological history as the critical factor in determining the present biodiversity and landscapes of Amazonia. We explore the different driving mechanisms for landscape evolution by reviewing the history of the Amazon Craton, the associated sedimentary basins, and the role of mountain uplift and climate change. Throughout the book we provide an insight into the Meso- and Cenozoic record of Amazonia that was characterized by fluvial and long-lived lake systems and a highly diverse flora and fauna. This fauna includes giants such as the ca. 12 m long caiman Purussaurus, but also a varied fish fauna and fragile molluscs, whilst fossil pollen and spores form relics of ancestral swamps and rainforests.
Finally, we review the molecular datasets of the modern Amazonian rainforest and aquatic ecosystem, and discuss the possible relations between the origin of Amazonian species diversity and the palaeogeographic, palaeoclimatic and palaeoenvironmental evolution of northern South America. The multidisciplinary approach in evaluating the history of Amazonia has resulted in a comprehensive volume that provides novel insights into the evolution of this region and can serve as reference for a variety of scientists working in Amazonia.
The book is written by leading scientists of the Amazonian research community and should be of interest to all students and researchers concerned with the natural history of Amazonia. Potential readers will include geologists, geographers and biologists who wish to understand the evolution of landscapes and biota of this unique region.
I hope to briefly review this book after its publication.
References:
Espinosa, J. & Ortega, J., 2009. Moluscos terrestres de Cuba: 1-191. Spartacus Foundation/Sociedad Cubana de Zoología.
Hoorn C. & Wesselingh, F. (eds.), 2010. Amazonia: landscape and species evolution. A look into the past: 1-447. Wiley-Blackwell.
Torre, C. de la & Bartsch, P., 2008. Los moluscos terrestres Cubanos de la familia Urocoptidae: 1-730 + 1-23. Editoria Científico-Técnica, La Habana/Ruth Casa, Panama.
Photo of the day (69): Drymaeus
15-10-2009 08:42
Living snails may be
difficult to find. Raúl Castro Zea, living in
Venezuela near Caracas, was lucky enough to obtain a
few specimens of Drymaeus.
This is a species that is quite variable, both in shell shape and in colour pattern. Hence many names are available in literature. It may be called D. menkei (Gruner, 1841), which is the oldest available name I could find for it. Notice the greyish colour of the body. The species is known from various places in northern Venezuela.
Thanks Raúl for supplying these pictures.
This is a species that is quite variable, both in shell shape and in colour pattern. Hence many names are available in literature. It may be called D. menkei (Gruner, 1841), which is the oldest available name I could find for it. Notice the greyish colour of the body. The species is known from various places in northern Venezuela.
Thanks Raúl for supplying these pictures.
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.
Another Blue Drymaeus
06-07-2009 21:34
There is a blue trait going around in
Caribbean
Drymaeus,
about which I have written
here
and
before.
Now I have evidence that the Blue
Drymaeus
clan extends into the mainland.
This is a picture of Drymaeus flavidus (Menke, 1828) from Venezuela, Edo. Miranda, Barlovento. The blue trait is thus present in de Cordillera de la Costa, and I wonder how far east and west it extends. If you have any observations on these “Blue Boys”, I’ll be happy to be informed.
Many thanks to Raúl Castro Zea, who kindly sent me this picture.
This is a picture of Drymaeus flavidus (Menke, 1828) from Venezuela, Edo. Miranda, Barlovento. The blue trait is thus present in de Cordillera de la Costa, and I wonder how far east and west it extends. If you have any observations on these “Blue Boys”, I’ll be happy to be informed.
Many thanks to Raúl Castro Zea, who kindly sent me this picture.
Climate change and tepuis
29-06-2009 20:57
Conservationists may be alarmed (again), although it
doesn’t concern a charismatic or a flagship species.
It’s about the ecosystem of the
tepuis.
And, although the threat is not immediate, it is a
serious one.
Valentí Rull has written, alone or together with members of his research group, many papers of interest about the Guayana Shield (Pantepui). Recently, one more appeared dealing with the potential effects of climate change on the tepui ecosystem. By modeling the shift of the biotas due to temperature rises of 2 and 4 degrees, they calculated the effects on the vascular plants. Evidence is provided that up to 45% of Pantepui species may be endangered with extinction due to habitat loss before the end of the century, if the temperature rises with 4 degrees.
The bromeliads in which snails have been found are on the list of species involved. The ecological ties between plants and snails may turn out unfavorable for the snails, given the fact that they are only occurring on the upper part of the tepuis and these communities are bound to be affected. Due to the flatness of these mountaintops there will be no escape...
Reference:
Nogué, S., Rull, V. & Vegas-Vilarrúbia, T., 2009. Modeling biodiversity loss by global warming on Pantepui, northern South America: projecting upward migration and potential habitat loss. - Climatic Change 94: 77-85.
Valentí Rull has written, alone or together with members of his research group, many papers of interest about the Guayana Shield (Pantepui). Recently, one more appeared dealing with the potential effects of climate change on the tepui ecosystem. By modeling the shift of the biotas due to temperature rises of 2 and 4 degrees, they calculated the effects on the vascular plants. Evidence is provided that up to 45% of Pantepui species may be endangered with extinction due to habitat loss before the end of the century, if the temperature rises with 4 degrees.
The bromeliads in which snails have been found are on the list of species involved. The ecological ties between plants and snails may turn out unfavorable for the snails, given the fact that they are only occurring on the upper part of the tepuis and these communities are bound to be affected. Due to the flatness of these mountaintops there will be no escape...
Reference:
Nogué, S., Rull, V. & Vegas-Vilarrúbia, T., 2009. Modeling biodiversity loss by global warming on Pantepui, northern South America: projecting upward migration and potential habitat loss. - Climatic Change 94: 77-85.
Chimantá
17-06-2009 19:27
The geological expedition that went to the Chimantá
massif last month, made this brief video that will
give you an impression of their results and about the
habitat of snails.
Inside the caves also snails have been found, belonging to the hydrobiids and yet to be described.
Inside the caves also snails have been found, belonging to the hydrobiids and yet to be described.
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.
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.
New taxa (11): Drymaeus
07-04-2009 07:50
The first new species that I would like to mention
from my
paper
on the tepuis from Venezuelan Guayana, is
Drymaeus
(D.)
rex
spec.nov.
The name was given for three reasons. First of all, it is a tribute to the herpetologist Roy McDiarmid who has always paid attention to snails and who collected the types. The epithet also refers to ‘ruadh’, an old word from Scottish Gealic which means red; it refers to the reddish apex that may be present in this taxon. Finally it refers to the majestical appearance of the living animal.
The holotype is in the Florida museum, UF 284726. All type material was collected during the interdisciplinary expedition to Cerro de la Neblina in 1983-1987, led by Charles Brewer-Carias.
The name was given for three reasons. First of all, it is a tribute to the herpetologist Roy McDiarmid who has always paid attention to snails and who collected the types. The epithet also refers to ‘ruadh’, an old word from Scottish Gealic which means red; it refers to the reddish apex that may be present in this taxon. Finally it refers to the majestical appearance of the living animal.
The holotype is in the Florida museum, UF 284726. All type material was collected during the interdisciplinary expedition to Cerro de la Neblina in 1983-1987, led by Charles Brewer-Carias.
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.
New taxa (8): Columbinia
13-01-2009 19:57
So far only orthalicid species are known from the
tepuis in Venezuelan Guayana. Fred Thompson just
described the first (but not the last?) Clausiliidae
from that region, collected during a very brief visit
to Cerro de la Neblina in 1984. This is the holotype
of
Columbinia
exul
sp.n. (UF 48631):
As the tepuis are geologically very old sandstone formations and there soils are acidic, they constitute special habitats to snails. Clausiliidae are more commonly found in more calcium-rich environments and the occurrence of this species on this isolated mountain is surely remarkable.
Conchologically, the species bears close resemblance to Neniops smithiae (Pilsbry, 1901), occurring in the isolated Sierra de Santa Marta, Colombia.
It is certainly possible that additional sampling on these tepuis will reveal other clausiliid species.
Reference
Thompson, F.G., 2008. The Clausiliid landsnail genus Columbinia in Venezuela, and the description of a new species. - Archiv für Molluskenkunde 137: 127-132.
As the tepuis are geologically very old sandstone formations and there soils are acidic, they constitute special habitats to snails. Clausiliidae are more commonly found in more calcium-rich environments and the occurrence of this species on this isolated mountain is surely remarkable.
Conchologically, the species bears close resemblance to Neniops smithiae (Pilsbry, 1901), occurring in the isolated Sierra de Santa Marta, Colombia.
It is certainly possible that additional sampling on these tepuis will reveal other clausiliid species.
Reference
Thompson, F.G., 2008. The Clausiliid landsnail genus Columbinia in Venezuela, and the description of a new species. - Archiv für Molluskenkunde 137: 127-132.
Tepuy
19-12-2008 13:05
Horizontal quartzite caves can’t exist according to
geological knowledge. Yet such caves have been found
in Venezuelan Guayana. Slovakian cavers have explored
the region and found several caves in Roraima and
Chimantá massifs. Of the latter expedition a
documentary has been made, called Tepuy, which
is
available
on DVD.
For all who would like to see this fascinating part of the world and to have an impression of the habitat of several interesting snail species, I recommend this film. Personally I give a five-star WOW!-factor.
For all who would like to see this fascinating part of the world and to have an impression of the habitat of several interesting snail species, I recommend this film. Personally I give a five-star WOW!-factor.
Photo of the day (27): Incidostosma
13-12-2008 14:23
This photo is part of an e-card with Season’s
Greeting that I received from Jozef Grego. It is
always nice to see a live snail instead of only a
shell. It is like seeing a photograph of a person
after you have read several of his/her publications.
You get a face to a name.
Thanks Jozef!
Thanks Jozef!
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.
Tepui fever
27-07-2008 16:35
When I recently got some information on the habitats
of snails from Venezuelan Guayana, I was curious to
find some more details on the plants and scenery.
Although I have the introductory volume of the Flora
of the Venzuelan Guayana, I wanted to see some more.
Quickly I discovered the important role of
Charles Brewer-Carías
as an explorer of this area.
Digging further I hit upon the site on a Czech speleologist who has been part of several expeditions, partly with Brewer-Carías. They have discovered several cave systems in the tepuis. Look here for some astonishing photography (follow the links to the galleries). Marvelous!
It really gives me what they call the tepui fever...
Digging further I hit upon the site on a Czech speleologist who has been part of several expeditions, partly with Brewer-Carías. They have discovered several cave systems in the tepuis. Look here for some astonishing photography (follow the links to the galleries). Marvelous!
It really gives me what they call the tepui fever...
Photo of the day (17): Drymaeus
19-07-2008 08:59
Roy McDiarmid (Smithsonian Institution) kindly sent
me some information on the expedition to the Cerro de
Neblina massif on the Venezuelan-Brazilian border, in
1984-1985. As it is a remote area that is difficult
to access, it has remained malacologically unknown.
One of the specimens he found there is this Drymaeus species:
One of the specimens he found there is this Drymaeus species:
The tail of a snail: more on Achatina
08-07-2008 07:17
Some snails have longer tails than others, especially
if they are so slimy like Achatina fulica is. But
first a note on taxonomy before we dive further into
the Neotropical story of it's distribution.
Fontanilla et al. (2007) reported on phylogenetic work with Achatina fulica and came to the conclusion that it should taxonomically designated Lissachatina fulica. There is a second species from East Africa which belongs to this genus (Fontanilla, pers. comm.). The interesting thing is that they found that all globally dispersed populations originate from a single haplotype, originating from East Africa.
Modesto Correoso, the only person who is doing serious work on land snails in Ecuador, kindly drew my attention to the fact that in 2005 he purchased some specimens of Lissachatina fulica on a market in Esmeraldas (northwestern Ecuador) and this fact was picked up by a journalist of the newspaper El Comercio.
This was evidently the source of the reference I wrote about last week. Later, Correoso wrote a paper in a technical bulletin of a local institution. Unfortunately this has escaped the attention of the scientific community, but I like to give credits to the person who deserves them.
So we might think that the story ends here. Just an unfortunate introduction of a species that has been more or less officially reported on. Children who have fun with it as pets and some people who are earning money with it.
But like in any good detective, the next, unexpected plot is just one page away...
The article in the newspaper was mentioned on a discussion forum on aquaculture. And from there the trail leads to Venezuela. Again. Because back in 1997, Rafael Martinez found already some shells near Caracas and reported on them. Not sure what happened exactly, but his paper gives the impression that this seemed a non-established population. However, from this blog entry it may be clear that L. fulica has now reached a pest status several hundreds kilometers west of the locality reported on by Martinez. So it is evident that the species has become well established in Venezuela, but to what extent is unclear at the moment.
This is certainly not a soap series, but I'm afraid I have to say: to be continued...
Update: Barbados is another place where L. fulica has been established, according to this blog. It is said to have entered the island through the port. Barbados has spent an estimated US$ 500,000 over the past eight years in an effort to eradicate the Giant African Snail that has been infesting crops in countries across the Caribbean.
Some of the comments to this blogpost:
"We are not the first country to be infested. The GAS have been on a world tour since leaving east Africa two centuries ago. It was only a matter of time before they reached our shores. It has been found that hand collecting is the best way to do away with them however you then have to kill them. Immersion in salt water doesn’t work too well and the odor produced is not pleasant. One test found that there was an 85% survival rate after 48 hours of soaking. Burning works but stinks. Same for boiling. The surest method is to make sure that the shell is well broken. I propose that the Min of Ag distribute appropriately coloured and stenciled plastic bags that homeowners can put out with the garbage. At the dump they can easily be sorted out, run through a crusher and buried in a deep trench.
When to collect them. Don’t waste your time if it hasn’t rained for 2 or 3 days but if it rains off and on and is overcast much of the day the snails will be out foraging. During the rainy season you can usually go out at 5 p.m. and collect several hundred before 6:30 p.m. If you go out at 5 a.m. you will likely be able to collect 6 to 700 per hour through to 8 a.m. when you will no longer find enough to warrant the effort. I roam over 2 acres of land every morning and some evenings. My best day I collected 3,000. For the month of November my total was 42,000. Since then the dry season has yielded an average of 15,000 per month."
According to Pestalert, this snail is besides Guadeloupe, Martinique and Barbados, also known from St. Lucia.
References:
Correoso, M. (2006). Estrategia preliminar para evaluar y erradicar Achatina fulica (Gastropoda: Achatineaceae) en Ecuador. Boletim Técnico IASA, Serie Zoológica, 2: 45-52.
Fontanilla, I. K., Hudelot, C., Naggs, F. & Wade, C.M. (2007). Achatina fulica: its molecular phylogeny and genetic variation in global populations. http://www.malacsoc.org.uk/The_Malacologist/BULL48/forum48.htm. Re-published: Abstracts World Congress of Malacology, Antwerp, 15-20 July 2007: 63.
Martinez, R. & Martinez, E. (1997). Nota acerca de la Achatina (Lissachatina) fulica (Bowdich, 1822). Peligroso caracol africano (Pulmonata-Achatinidae) introducido en Venezuela. Acta Biologica Venezuelica, 17: 37-40.
Fontanilla et al. (2007) reported on phylogenetic work with Achatina fulica and came to the conclusion that it should taxonomically designated Lissachatina fulica. There is a second species from East Africa which belongs to this genus (Fontanilla, pers. comm.). The interesting thing is that they found that all globally dispersed populations originate from a single haplotype, originating from East Africa.
Modesto Correoso, the only person who is doing serious work on land snails in Ecuador, kindly drew my attention to the fact that in 2005 he purchased some specimens of Lissachatina fulica on a market in Esmeraldas (northwestern Ecuador) and this fact was picked up by a journalist of the newspaper El Comercio.
This was evidently the source of the reference I wrote about last week. Later, Correoso wrote a paper in a technical bulletin of a local institution. Unfortunately this has escaped the attention of the scientific community, but I like to give credits to the person who deserves them.
So we might think that the story ends here. Just an unfortunate introduction of a species that has been more or less officially reported on. Children who have fun with it as pets and some people who are earning money with it.
But like in any good detective, the next, unexpected plot is just one page away...
The article in the newspaper was mentioned on a discussion forum on aquaculture. And from there the trail leads to Venezuela. Again. Because back in 1997, Rafael Martinez found already some shells near Caracas and reported on them. Not sure what happened exactly, but his paper gives the impression that this seemed a non-established population. However, from this blog entry it may be clear that L. fulica has now reached a pest status several hundreds kilometers west of the locality reported on by Martinez. So it is evident that the species has become well established in Venezuela, but to what extent is unclear at the moment.
This is certainly not a soap series, but I'm afraid I have to say: to be continued...
Update: Barbados is another place where L. fulica has been established, according to this blog. It is said to have entered the island through the port. Barbados has spent an estimated US$ 500,000 over the past eight years in an effort to eradicate the Giant African Snail that has been infesting crops in countries across the Caribbean.
Some of the comments to this blogpost:
"We are not the first country to be infested. The GAS have been on a world tour since leaving east Africa two centuries ago. It was only a matter of time before they reached our shores. It has been found that hand collecting is the best way to do away with them however you then have to kill them. Immersion in salt water doesn’t work too well and the odor produced is not pleasant. One test found that there was an 85% survival rate after 48 hours of soaking. Burning works but stinks. Same for boiling. The surest method is to make sure that the shell is well broken. I propose that the Min of Ag distribute appropriately coloured and stenciled plastic bags that homeowners can put out with the garbage. At the dump they can easily be sorted out, run through a crusher and buried in a deep trench.
When to collect them. Don’t waste your time if it hasn’t rained for 2 or 3 days but if it rains off and on and is overcast much of the day the snails will be out foraging. During the rainy season you can usually go out at 5 p.m. and collect several hundred before 6:30 p.m. If you go out at 5 a.m. you will likely be able to collect 6 to 700 per hour through to 8 a.m. when you will no longer find enough to warrant the effort. I roam over 2 acres of land every morning and some evenings. My best day I collected 3,000. For the month of November my total was 42,000. Since then the dry season has yielded an average of 15,000 per month."
According to Pestalert, this snail is besides Guadeloupe, Martinique and Barbados, also known from St. Lucia.
References:
Correoso, M. (2006). Estrategia preliminar para evaluar y erradicar Achatina fulica (Gastropoda: Achatineaceae) en Ecuador. Boletim Técnico IASA, Serie Zoológica, 2: 45-52.
Fontanilla, I. K., Hudelot, C., Naggs, F. & Wade, C.M. (2007). Achatina fulica: its molecular phylogeny and genetic variation in global populations. http://www.malacsoc.org.uk/The_Malacologist/BULL48/forum48.htm. Re-published: Abstracts World Congress of Malacology, Antwerp, 15-20 July 2007: 63.
Martinez, R. & Martinez, E. (1997). Nota acerca de la Achatina (Lissachatina) fulica (Bowdich, 1822). Peligroso caracol africano (Pulmonata-Achatinidae) introducido en Venezuela. Acta Biologica Venezuelica, 17: 37-40.
Photo of the day (8): Dryptus
13-04-2008 15:45
Today I show a recently received picture of Dryptus
marmoratus (Dunker, 1844) from Venezuela, Estado
Aragua, National Park 'Henri Pittier', made in
January 2008.
Photo by Jozef Steffek
Photo by Jozef Steffek
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....