mei 2009
Photo of the day (51): Proserpina
28-05-2009 22:05
The thread on Cuban land snails is continued today
with some pictures that I received of
Proserpina.
This genus belongs to the family Proserpinidae. The
species of the Greater Antilles were revised by Boss
& Jacobson (1975a), who published also a
catalogue of all taxa of the family (1975b). They
wrote “Proserpina
and its allies constitute a unique group of
prosobranch land snails in that they have lost the
characteristic operculum, have developed apertural
lamellae, and have a mantle that may extend and
envelop the shell” (Boss & Jacobson, 1975a: 53).
The photographs presented today are Proserpina depressa (Orbigny, 1842). These pictures were taken by Adrián González Guillén in Prov. Pinar del Río, near Viñales and San Carlos valley. This species shows a remarkable disjunct distribution, both being present in the western and eastern part of the island.
Wonderful snails to see and the interesting fact is that Adrián noted that two different morphs were encountered.
It is clear that more research in this genus may lead to interesting discoveries.
Many thanks Adrián, for sharing these pictures here.
References:
Boss, K.J. & Jacobson, M.K., 1975a. Proserpine snails of the Greater Antilles. - Occasional Papers on Mollusks 51: 53-90.
Boss, K.J. & Jacobson, M.K., 1975b. Catalogue of the taxa of the subfamily Proserpininae (Helicinidae: Prosobranchia). - Occasional Papers on Mollusks 52: 93-102.
The photographs presented today are Proserpina depressa (Orbigny, 1842). These pictures were taken by Adrián González Guillén in Prov. Pinar del Río, near Viñales and San Carlos valley. This species shows a remarkable disjunct distribution, both being present in the western and eastern part of the island.
Wonderful snails to see and the interesting fact is that Adrián noted that two different morphs were encountered.
It is clear that more research in this genus may lead to interesting discoveries.
Many thanks Adrián, for sharing these pictures here.
References:
Boss, K.J. & Jacobson, M.K., 1975a. Proserpine snails of the Greater Antilles. - Occasional Papers on Mollusks 51: 53-90.
Boss, K.J. & Jacobson, M.K., 1975b. Catalogue of the taxa of the subfamily Proserpininae (Helicinidae: Prosobranchia). - Occasional Papers on Mollusks 52: 93-102.
New taxa (15): Idiostemma
27-05-2009 21:28
In my series on new taxa introduced to the
Neotropical land-snail fauna, I still have to catch
up with some “oldies”. Today a paper by Franke &
Fernández (2007), who described a new urocoptid
species from Cuba, Prov. Holguin, Banes, Cerro de
Yaguajay.
It is called Idiostemma alfredoi. The holotype is in the Holguin Natural History Museum; paratypes are in the Berlin museum.
Although all pictures in the paper are black/white, some of them are nicely picturing the habitat of this new taxon.
Reference:
Franke, S. & Fernández V., A., 2007. A new land snail of the genus Idiostemma Pilsbry & Vanatta, 1898 (Gastropoda: Urocoptidae) from Eastern Cuba. - Schriften zur Malakozoologie 23: 79-86.
It is called Idiostemma alfredoi. The holotype is in the Holguin Natural History Museum; paratypes are in the Berlin museum.
Although all pictures in the paper are black/white, some of them are nicely picturing the habitat of this new taxon.
Reference:
Franke, S. & Fernández V., A., 2007. A new land snail of the genus Idiostemma Pilsbry & Vanatta, 1898 (Gastropoda: Urocoptidae) from Eastern Cuba. - Schriften zur Malakozoologie 23: 79-86.
Online publication
25-05-2009 14:48
There is some debate now on the
TaxCom mailing list
about the recent publication of Costello (2009). His
paper argues that biodiversity data should be
published online, but that “scientists’ concerns
about these efforts have not been answered and
initiatives to motivate scientists to comply have
been inadequate”.
It cannot be denied that online publication can be a powerful tool and there are several nice examples that could be mentioned. To name just a few that I have recently accessed: Gary Rosenberg’s site on Jamaican molluscs and the World Spiders Catalog, maintained by Norman Platnick. [No, I’m not switching from malacology to arachnology...]. These are sites made and maintained by individual specialists; besides these selective exemples, many more could be cited. My impression is that quality is excellent to good and possibly the main caveat is that, after a while and for whatever reason, the site is no longer updated.
The other extreme are sites (or rather portals) than host a huge amount of data and make these available for further use. A well-known example is the Global Biodiversity Information Facility (GBIF). Unfortunately, it is also this example that shows the pitfalls of these data centers. As far as my specialism is concerned, the data is notoriously unreliable. It is also outrageously incomplete. And that’s one of the main points of Costello’s critique: many primary data, which were gathered using public funds, are not available through data centers for further research and several other benefits that are listed in his paper.
His proposal is to drastically alter the way scientists publish their data, moving them from print to online data centers.
There are several useful suggestions made in his paper to motivate people for online publication, e.g. to stimulate the use of giving credit to authors who upload data, to facilitate the use of tools (such as Scratchpads) and requirements by funding agencies.
The advantages of online publication are clear. However, I feel that we still have a long way to go. To name a few of the remaining stumble blocks: quality checking, involvement of scientific amateurs (who also generate primary data) and to re-think the business model that sustains now many societies that issue scientific journals. Not all publications are commercial and hence publishing data as such can have adverse effects which have not been mentioned so far.
I know, there is much more that can be said about this topic...
Reference:
Costello, M., 2009. Motivating online publication of data. BioScience 59: 418-427.
It cannot be denied that online publication can be a powerful tool and there are several nice examples that could be mentioned. To name just a few that I have recently accessed: Gary Rosenberg’s site on Jamaican molluscs and the World Spiders Catalog, maintained by Norman Platnick. [No, I’m not switching from malacology to arachnology...]. These are sites made and maintained by individual specialists; besides these selective exemples, many more could be cited. My impression is that quality is excellent to good and possibly the main caveat is that, after a while and for whatever reason, the site is no longer updated.
The other extreme are sites (or rather portals) than host a huge amount of data and make these available for further use. A well-known example is the Global Biodiversity Information Facility (GBIF). Unfortunately, it is also this example that shows the pitfalls of these data centers. As far as my specialism is concerned, the data is notoriously unreliable. It is also outrageously incomplete. And that’s one of the main points of Costello’s critique: many primary data, which were gathered using public funds, are not available through data centers for further research and several other benefits that are listed in his paper.
His proposal is to drastically alter the way scientists publish their data, moving them from print to online data centers.
There are several useful suggestions made in his paper to motivate people for online publication, e.g. to stimulate the use of giving credit to authors who upload data, to facilitate the use of tools (such as Scratchpads) and requirements by funding agencies.
The advantages of online publication are clear. However, I feel that we still have a long way to go. To name a few of the remaining stumble blocks: quality checking, involvement of scientific amateurs (who also generate primary data) and to re-think the business model that sustains now many societies that issue scientific journals. Not all publications are commercial and hence publishing data as such can have adverse effects which have not been mentioned so far.
I know, there is much more that can be said about this topic...
Reference:
Costello, M., 2009. Motivating online publication of data. BioScience 59: 418-427.
Photo of the day (50): Orthalicus
22-05-2009 19:28
This
Orthalicus
ponderosus
Strebel & Pfeffer, 1882 originates from Mexico,
Jalisco, Punta Pérula area and was captured on logs
of
Dalbergia
retusa
when imported in the USA.
Photos taken by Eric McDonald, courtesy of David Robinson.
Photos taken by Eric McDonald, courtesy of David Robinson.
Molluscan radiation and landscape evolution in Amazonia
21-05-2009 16:02
Yesterday in Naturalis museum we had a special
meeting to honour two colleagues who got their Ph.D.
a few months ago. I will mention briefly here the
work of Frank Wesselingh, as his thesis* is related
to the Neotropics.
His research centered on the Pebas formation in eastern Peru and northwestern Brazil and relates to the freshwater molluscs found as fossils.
When he started his research, only pollen data were known that spanned a couple of million years. Studying the snails, he found many new species and some new genera (see references in Wesselingh, 2008; or his personal page at Naturalis). All but one species are now extinct.
As the above pictures shows, his results allowed him to study the landscape evolution of western Amazonia. This is highly relevant, also to land-snails, as it may provide evidence about e.g. the connections between the Andes and the Guayana Shield.
Later this year a book will be published in which this topic will be elaborated.
Reference:
Wesseling, F.P., 2008. Molluscan radiations and landscape evolution in Miocene Amazonia. - Annales Universitates Turkuensis, 232: 1-41. Thesis defended 21 February 2009.
His research centered on the Pebas formation in eastern Peru and northwestern Brazil and relates to the freshwater molluscs found as fossils.
When he started his research, only pollen data were known that spanned a couple of million years. Studying the snails, he found many new species and some new genera (see references in Wesselingh, 2008; or his personal page at Naturalis). All but one species are now extinct.
As the above pictures shows, his results allowed him to study the landscape evolution of western Amazonia. This is highly relevant, also to land-snails, as it may provide evidence about e.g. the connections between the Andes and the Guayana Shield.
Later this year a book will be published in which this topic will be elaborated.
Reference:
Wesseling, F.P., 2008. Molluscan radiations and landscape evolution in Miocene Amazonia. - Annales Universitates Turkuensis, 232: 1-41. Thesis defended 21 February 2009.
Malacophagy
20-05-2009 19:52
Even seen a wobbling, empty shell?
Today an observation on hearsay evidence by my youngest son. In my garden there is a little pond, one of the edges is partly overgrown by Hedera. Frogs are continuous inhabitants and in springtime the tadpoles are a favourite prey for one of the neighbour’s cats (someone said that they might get high on them). But this afternoon, my son saw how three tadpoles started to feed on an unlucky Cornu aspersum that felt off the Hedera plants into the water.
When I came home a couple of hours later, my son recalled his observation during dinner. I quickly went to the pond to look at the ‘locus delictus’. Only to find a dead snail floating on the water.
Just a few centimeters away the empty shell was floating on the water. I picked it up and laid it on the edge and grabbed my camera to take pictures.
That’s when the wobbling started.
Closer examination revealed the originator of this movement. A (possibly succineid) snail had attached itself to the bigger shell. Will need to examine it in the lab next week to be sure of its identity.
Malacophagy is not uncommon in various groups of animals. Barker (2004) lists mammals, birds, beetles, flies, spiders and various other groups (including carnivorous molluscs) as predators. But I never heard of tadpoles attacking snails. However, this may be incidentally and to be seen as ‘an occasion not to be missed’. From the viewpoint of the tadpoles..., of course. Eat and be eaten. Nature’s laws can be cruel.
Reference:
Barker, G.M. (ed.), 2004. Natural enemies of terrestrial molluscs: 1-640. CAB International, Wallingford, U.K.
Today an observation on hearsay evidence by my youngest son. In my garden there is a little pond, one of the edges is partly overgrown by Hedera. Frogs are continuous inhabitants and in springtime the tadpoles are a favourite prey for one of the neighbour’s cats (someone said that they might get high on them). But this afternoon, my son saw how three tadpoles started to feed on an unlucky Cornu aspersum that felt off the Hedera plants into the water.
When I came home a couple of hours later, my son recalled his observation during dinner. I quickly went to the pond to look at the ‘locus delictus’. Only to find a dead snail floating on the water.
Just a few centimeters away the empty shell was floating on the water. I picked it up and laid it on the edge and grabbed my camera to take pictures.
That’s when the wobbling started.
Closer examination revealed the originator of this movement. A (possibly succineid) snail had attached itself to the bigger shell. Will need to examine it in the lab next week to be sure of its identity.
Malacophagy is not uncommon in various groups of animals. Barker (2004) lists mammals, birds, beetles, flies, spiders and various other groups (including carnivorous molluscs) as predators. But I never heard of tadpoles attacking snails. However, this may be incidentally and to be seen as ‘an occasion not to be missed’. From the viewpoint of the tadpoles..., of course. Eat and be eaten. Nature’s laws can be cruel.
Reference:
Barker, G.M. (ed.), 2004. Natural enemies of terrestrial molluscs: 1-640. CAB International, Wallingford, U.K.
Photo of the day (49): Plectostylus
19-05-2009 18:59
Imagine that you see a mossy tree stem from some
distance. Would you spot the snail on it? Certainly
if you are so near as where this picture was taken
of
Plectostylus
variegatus
(Pfeiffer, 1842).
This photograph was taken in January 2009 by Ad Hovestadt in Chile, Coquimbo, south of La Serena, Parque Nacional Fray Jorge, in cloud forest.
Thanks Ad!
This photograph was taken in January 2009 by Ad Hovestadt in Chile, Coquimbo, south of La Serena, Parque Nacional Fray Jorge, in cloud forest.
Thanks Ad!
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.
Rapid assessment in Cuba
15-05-2009 11:30
During a literature survey on
Liguus,
I came across a
report
(Diaz et al., 2006) that was published some years
ago. It is the result of a joint Cuban-American
assessment of the biodiversity in part of the
province Camagüey in east Cuba, the Sierra de
Cubitas.
Malacology is but a small part of the results, for which field observations were made during four days in September 2002. The only picture of snails is, however, from Liguus fasciatus.
It is a new record for the Sierra de Cubitas and together with another new record for Steatocoptis bioscati, the total number of molluscs for the area is 50.
When I glanced through the report, my eyes caught some interesting sentences related to Opisthosiphon (Annulariidae). Four species of this genus occur in the Sierra de Cubitos: O. banoense, O. evanidum, O. greenfieldi, and O. obturatum. “Individuals of the four species were seen copulating with one another and I was able to determine that females always have a pattern of dark stripes on their shells, while the males have pale or dark shells without those stripes.” The authors add that this observation should serve as a starting point for a taxonomic review of the genus.
It is precisely observations like this which can only be made in the field and which make these reports special. A little gem found, that I wanted to pass on to you.
More reports from the same series, covering also other Neotropical countires, can be found here. However, not all contain data on molluscs. Actually, only a few others related to Cuba...
Reference:
Díaz, L.M., Alverson, W.S., Barreto, A. & Wachter,T., 2006. Cuba: Camagüey, Sierra de Cubitas: 1-180. Rapid Biological Inventories Report 08. The Field Museum, Chicago.
Malacology is but a small part of the results, for which field observations were made during four days in September 2002. The only picture of snails is, however, from Liguus fasciatus.
It is a new record for the Sierra de Cubitas and together with another new record for Steatocoptis bioscati, the total number of molluscs for the area is 50.
When I glanced through the report, my eyes caught some interesting sentences related to Opisthosiphon (Annulariidae). Four species of this genus occur in the Sierra de Cubitos: O. banoense, O. evanidum, O. greenfieldi, and O. obturatum. “Individuals of the four species were seen copulating with one another and I was able to determine that females always have a pattern of dark stripes on their shells, while the males have pale or dark shells without those stripes.” The authors add that this observation should serve as a starting point for a taxonomic review of the genus.
It is precisely observations like this which can only be made in the field and which make these reports special. A little gem found, that I wanted to pass on to you.
More reports from the same series, covering also other Neotropical countires, can be found here. However, not all contain data on molluscs. Actually, only a few others related to Cuba...
Reference:
Díaz, L.M., Alverson, W.S., Barreto, A. & Wachter,T., 2006. Cuba: Camagüey, Sierra de Cubitas: 1-180. Rapid Biological Inventories Report 08. The Field Museum, Chicago.
Snails and spiders (3)
14-05-2009 19:35
Again, slightly off track, on the subject of snails
and spiders. It was discussed in literature already
many years ago; e.g. Bristowe (1939-1941) considered
malacophagy by spiders as an impossibility, due to
the fact that shells and mucus were successfully
defense mechanisms of gastropods. Although even today
some arachnologists are of the same opinion (De
Winter, pers. comm.), there is now enough evidence to
the contrary (Nyfeller & Symondson, 2001; Pollard
& Jackson, 2004). The first report of a spider
feeding on snails dates back to the 19th century
(Johnson, 1863).
In their review, Nyfeller & Symondson (2001) list 53 reported observations of predation on snails and slugs. Some of these observations were made in captivity, but most in the field. For a casual observation of malacophagy, see Du Preez (2001).
However, malacophagy does not necessarily play a role in spider-snail interactions. Spiders can also use shells for shelter (e.g. Mikulska, 1961) or nesting sites (e.g. Moreno-Rueda et al., 2008). It is probably this second role that was observed by Deeleman-Reinhold and mentioned in my first post on this subject.
References:
Bristowe, W.S., 1939-1941. The comity of spiders, 2 vols.: 1-228. - Ray Society, London.
Du Preez, K., 2001. Snaily tales. - Strandloper 266: 10-12.
Johnson, J.Y., 1863. Description of a Lycosa from Madeira. - Annals and Magazine of Natural History 12: 152.
Mikulska, I., 1961. Parental care in a rare spider Pellenes nigrocileatus (L. Koch) var. bilunulata Simon. - Nature 190: 365-366.
Moreno-Rueda, G., Marfil-Daza, C., Ortiz-Sánchez, F.J. & Melic, A., 2008. Weather and the use of empty gastropod shells by arthopods. - Annales de la Société Entomologique de France (n.s.) 44: 373-377.
Nyfeller, M. & Symondson, W.O.C., 2001. Spiders and harvestmen as gastropod predators. - Ecological Entomology 26: 617-628.
Pollard, S.D. & Jackson, R.R., 2004. Gastropod predation in spiders (Araneae). In: G.M. Barker (ed.), Natural enemies of terrestrial molluscs: 497-503. - CAB International, Wallingford, U.K.
In their review, Nyfeller & Symondson (2001) list 53 reported observations of predation on snails and slugs. Some of these observations were made in captivity, but most in the field. For a casual observation of malacophagy, see Du Preez (2001).
However, malacophagy does not necessarily play a role in spider-snail interactions. Spiders can also use shells for shelter (e.g. Mikulska, 1961) or nesting sites (e.g. Moreno-Rueda et al., 2008). It is probably this second role that was observed by Deeleman-Reinhold and mentioned in my first post on this subject.
References:
Bristowe, W.S., 1939-1941. The comity of spiders, 2 vols.: 1-228. - Ray Society, London.
Du Preez, K., 2001. Snaily tales. - Strandloper 266: 10-12.
Johnson, J.Y., 1863. Description of a Lycosa from Madeira. - Annals and Magazine of Natural History 12: 152.
Mikulska, I., 1961. Parental care in a rare spider Pellenes nigrocileatus (L. Koch) var. bilunulata Simon. - Nature 190: 365-366.
Moreno-Rueda, G., Marfil-Daza, C., Ortiz-Sánchez, F.J. & Melic, A., 2008. Weather and the use of empty gastropod shells by arthopods. - Annales de la Société Entomologique de France (n.s.) 44: 373-377.
Nyfeller, M. & Symondson, W.O.C., 2001. Spiders and harvestmen as gastropod predators. - Ecological Entomology 26: 617-628.
Pollard, S.D. & Jackson, R.R., 2004. Gastropod predation in spiders (Araneae). In: G.M. Barker (ed.), Natural enemies of terrestrial molluscs: 497-503. - CAB International, Wallingford, U.K.
Colours, Cuba, Liguus
13-05-2009 21:48
Species of
Liguus
are very abundant on Cuba, and usually very
colourful. Or rather should I say: ‘varieties’,
colour forms’ or ‘subspecies’, as Hillis et al.
(1991) showed the various morphs can be grouped
genetically into a limited number of species.
Last year a beautiful book was published on Cuban land-snails (González Guillén, 2008); it was mentioned briefly in this and this post. Upon my request, the author sent me several pictures of Liguus, illustrating the bewildering variation as far as the colour pattern goes. Each colour form is restricted to a small area of limestone hill(s); in Cuba called ‘mogote’. Many of these morphs are already extinct or highly endangered, due to the destruction of the mogotes for tourism (or economic ‘development’). Still, there is none of them listed on the IUCN Red List 2008. I have expressed my doubts about the listing procedure earlier here.
Much has already been written about Liguus, most often in popular articles. Yet, the genetical mechanism is incompletely known and the phylogeography is still poorly understood. In my humble opinion, Liguus needs urgently more attention.
Many thanks to Andrián González for sending me these stunning pictures. From left to right, top to bottom: Liguus fasciatus achatinus Clench, 1934; L. f. goodrichi Clench, 1934; L. f. torrei Clench, 1934; L. flammellus bermudezi Clench, 1934.
References:
González Guillén, A., 2008. Cuba, the landshells paradise: 1-306. - Greta Editores, Lleida.
Hillis, D.M., Dixon, M.T. & Jones, A.L., 1991. Minimal genetic variation in a morphologically diverse species (Florida tree snail, Liguus fasciatus). - Journal of Heredity 82: 282-286.
Last year a beautiful book was published on Cuban land-snails (González Guillén, 2008); it was mentioned briefly in this and this post. Upon my request, the author sent me several pictures of Liguus, illustrating the bewildering variation as far as the colour pattern goes. Each colour form is restricted to a small area of limestone hill(s); in Cuba called ‘mogote’. Many of these morphs are already extinct or highly endangered, due to the destruction of the mogotes for tourism (or economic ‘development’). Still, there is none of them listed on the IUCN Red List 2008. I have expressed my doubts about the listing procedure earlier here.
Much has already been written about Liguus, most often in popular articles. Yet, the genetical mechanism is incompletely known and the phylogeography is still poorly understood. In my humble opinion, Liguus needs urgently more attention.
Many thanks to Andrián González for sending me these stunning pictures. From left to right, top to bottom: Liguus fasciatus achatinus Clench, 1934; L. f. goodrichi Clench, 1934; L. f. torrei Clench, 1934; L. flammellus bermudezi Clench, 1934.
References:
González Guillén, A., 2008. Cuba, the landshells paradise: 1-306. - Greta Editores, Lleida.
Hillis, D.M., Dixon, M.T. & Jones, A.L., 1991. Minimal genetic variation in a morphologically diverse species (Florida tree snail, Liguus fasciatus). - Journal of Heredity 82: 282-286.
Biohistorical notes (7): W. Dunker
12-05-2009 20:00
Wilhelm Bernhard Rudolph Hadrian were the Christian
names of the malacologist who is usually referred to
as W. Dunker or just Dunker. Although I’m actually
unsure about the total amount of Neotropical taxa in
his work, I know that there are six papers bearing
his name as an (co-)author in the bibliography of my
revision of Bulimulinae (Breure, 1979). I would not
be surprised to find his name associated with other
families relevant to the Neotropics as well.
Wilhem Dunker (1809-1885); after Tëmkin et al., 2009
The following biographical information is taken from a recent publication by Tëmkin et al. (2009). Dunker was a professor of geology and mineralogy, and was among the leading malacologists of his time. “Dunker’s reputation as a distinguished conchologist grew along with his collection and soon material from all over the world was sent to him”. The Dunker collection comprised a large amount of type specimens is now part of the Museum für Naturkunde in Berlin. The authors provide some evidence that this may have been larger than the well-known Cuming collection.
Furthermore, there is evidence that Dunker was in contact with Gundlach, but there is no doubt that there were many contacts with L. Pfeiffer.
Although the main part of the publication is on marine molluscs, I found the paper as such interesting as it is part of an ongoing project on type specimens in the Berlin museum (see also Köhler, 2007) and contains biohistorical data that were previously unpublished.
References:
Breure, A.S.H., 1979. Systematics, phylogeny and zoogeography of Bulimulinae (Mollusca). - Zoologische Verhandelingen 168: 1-215.
Köhler, F., 2007. Annotated type catalogue of the Bulimulidae (Pulmonata, Orthalicoidea, Bulimulidae) in the Museum für Naturkunder Berlin. - Mittheilungen Museum naturkunde Berlin, Zoologische Reihe 83: 125-159.
Tëmkin, I., Glaubrecht, M. & Köhler, F., 2009. Wilhelm Dunker, his collection, and pteriid systematics. - Malacologia 51: 39-79.
Wilhem Dunker (1809-1885); after Tëmkin et al., 2009
The following biographical information is taken from a recent publication by Tëmkin et al. (2009). Dunker was a professor of geology and mineralogy, and was among the leading malacologists of his time. “Dunker’s reputation as a distinguished conchologist grew along with his collection and soon material from all over the world was sent to him”. The Dunker collection comprised a large amount of type specimens is now part of the Museum für Naturkunde in Berlin. The authors provide some evidence that this may have been larger than the well-known Cuming collection.
Furthermore, there is evidence that Dunker was in contact with Gundlach, but there is no doubt that there were many contacts with L. Pfeiffer.
Although the main part of the publication is on marine molluscs, I found the paper as such interesting as it is part of an ongoing project on type specimens in the Berlin museum (see also Köhler, 2007) and contains biohistorical data that were previously unpublished.
References:
Breure, A.S.H., 1979. Systematics, phylogeny and zoogeography of Bulimulinae (Mollusca). - Zoologische Verhandelingen 168: 1-215.
Köhler, F., 2007. Annotated type catalogue of the Bulimulidae (Pulmonata, Orthalicoidea, Bulimulidae) in the Museum für Naturkunder Berlin. - Mittheilungen Museum naturkunde Berlin, Zoologische Reihe 83: 125-159.
Tëmkin, I., Glaubrecht, M. & Köhler, F., 2009. Wilhelm Dunker, his collection, and pteriid systematics. - Malacologia 51: 39-79.
Snails and spiders (2)
11-05-2009 20:42
In reaction to my
previous
post,
Adrián González Guillén sent me some pictures of
Cuban land shells showing the same phenomenon.
According to him “it´s well known in several
species of Annulariidae land shells of Cuba and
for sure in the Caribbean islands. In fact, in my
book ¨Cuba. The Landshells Paradise¨ (2008) I
mention this weird behaviour of land shells
hanging their selves with a ¨mucus rope¨ create[d]
by the animals, like something perhaps linked in
the evolutionary history of that operculate snails
species with predators, physiology or enviromental
factors. Who knows?”. One of the examples he
supplied is
Chondropometes
magnum
from Cuba.
A very quick search in Scholar didn’t reveal any relevant reference about mucous threads and snails, other than to marine and freshwater molluscs. I wonder if anything has been reported in the scientific malacological literature. Perhaps the observation in Borneo with spiderlings associated to shells was merely by chance. If the threads are really mucous from the snails, one would suspect some evolutionary advantage connected to this behaviour.
If you have any suggestion, please let me know.
A very quick search in Scholar didn’t reveal any relevant reference about mucous threads and snails, other than to marine and freshwater molluscs. I wonder if anything has been reported in the scientific malacological literature. Perhaps the observation in Borneo with spiderlings associated to shells was merely by chance. If the threads are really mucous from the snails, one would suspect some evolutionary advantage connected to this behaviour.
If you have any suggestion, please let me know.
Snails and spiders
07-05-2009 20:05
Not about Neotropical snails today, but an
observation made by Christa Deeleman in Malaysian
Borneo when she collected spiders in the Gunung Mulu
National Park. Kneeling on the ground next to a
vertical limestone slab, she noticed the presence of
small objects suspended by thin lines to the slab
surface. The objects proved to be small land snails,
later identified by Dolf van Bruggen as an
Alycaeus
species (Cyclophoridae).
As an arachnologist she associated the lines with spiders. She collected a number of the shells and examined them at home under a microscope. The shells were all sealed with an operculum and apparently were alive at the time of collecting. In one of the shells a spiderling was found.
Were these shells used as a resting place? As a place to hide egg sacs? And why were those shells hanging in the air?
In literature, one case has been reported from Madagascar where spiders used empty shells for resting and to hide their egg sacs (Fage, 1926). However, living snails of this genus as known to adhere themselves to limestone rocks (Schilthuizen et al, 1999).
Currently, the precise nature of this observation remains unknown.
References:
Fage, L., 1926. Sur quelques araignées de Madagascar, nouvelles ou peu connues et sur leur curieuse industrie. - Archives Zoologique Expérimentales 65: 5-17.
Schilthuizen, M., Vermeulen, J.J. & Davison, G.W.H., 1999. A note on the ecology of West-Malaysian calcicolous snails (Mollusca: Gastropoda: Diplommatinidae, Cyclophoridae, Vertiginidae, Streptaxidae). - Malayan Nature Journal 53: 351-354.
As an arachnologist she associated the lines with spiders. She collected a number of the shells and examined them at home under a microscope. The shells were all sealed with an operculum and apparently were alive at the time of collecting. In one of the shells a spiderling was found.
Were these shells used as a resting place? As a place to hide egg sacs? And why were those shells hanging in the air?
In literature, one case has been reported from Madagascar where spiders used empty shells for resting and to hide their egg sacs (Fage, 1926). However, living snails of this genus as known to adhere themselves to limestone rocks (Schilthuizen et al, 1999).
Currently, the precise nature of this observation remains unknown.
References:
Fage, L., 1926. Sur quelques araignées de Madagascar, nouvelles ou peu connues et sur leur curieuse industrie. - Archives Zoologique Expérimentales 65: 5-17.
Schilthuizen, M., Vermeulen, J.J. & Davison, G.W.H., 1999. A note on the ecology of West-Malaysian calcicolous snails (Mollusca: Gastropoda: Diplommatinidae, Cyclophoridae, Vertiginidae, Streptaxidae). - Malayan Nature Journal 53: 351-354.
A new book announced
05-05-2009 21:39
Books on Neotropical snails are scarce and additions
are very welcome. Modesto Correoso send me notice
that - after a long production process - his book on
non-marine snails of continental Ecuador has recently
been published.
Awaiting further details on this new addition to the malacological library, I’ll keep you posted once the copy ordered arrives on my desk.
Update:
Here is a picture of the formal presentation of the book (the author at left).
Awaiting further details on this new addition to the malacological library, I’ll keep you posted once the copy ordered arrives on my desk.
Update:
Here is a picture of the formal presentation of the book (the author at left).
Charles Johnson Maynard's Cerion's
04-05-2009 19:33
Charles Johnson Maynard (1845-1929) was a naturalist,
ornitologist and malacologist, who explored the
Bahamas and Cayman Islands and described many
Cerions.
He was a teacher and also a dealer of natural history specimens. Clench (1957: 123) wrote about him:
"His work was marred by many inaccuracies of all kinds and his attempts towards a clarification of this complex problem dwindled as the years passed, ending in brief descriptions and eventually a sales catalogue with a few "new species" described. In fairness to Maynard, however, the commercial side of his venture was not to gain profit for himself but to realize money to finance additional expeditions in quest of these mollusks in which he was so deeply interested. It seems to me that Maynard failed to grasp much of the importance of his own discoveries... Nevertheless, we owe much to Maynard for his early exploration of both the Bahama Islands and the Cayman Islands, as the specimens he collected are still the only materials available for study from many remote and inaccessible localities."
In total 248 Cerion species-level names have been proposed by Maynard, of which the type specimens were revised by Harasewych et al. (2007). It has to be said to Maynard’s credit, that the type material of nearly all his taxa has been preserved is and is now mainly in the MCZ (Boston) and USNM (Washington). Only for eight taxa neotypes had to be selected.
However, with this overwhelming number of ‘species’, one could easily ask: “what did he see that I don’t see?”. Needless to say that many of his taxa are now considered synonyms.
For a full account of his malacological work, including a biography, see Turner (1957).
References:
Clench, W.J., 1957. A catalog of the Cerionidae (Mollusca: Pulmonata). - Bulletin of the Museum of Comparative Zoology 116: 121-169.
Harasewych, M.G., Baldinger, A., Villacampa, Y. & Greenhall. P., 2007. The Cerion (Mollusca: Gastropoda: Pulmonata: Cerionidae) taxa of Charles Johnson Maynard nd their type species. - Bulletin of the Museum of Comparative Zoology 158: 367-523.
Turner, R.D., 1957. Charles Johnson Maynard and his work in malacology. - Occasional Papers on Mollusks 2 (21): 137-152.
He was a teacher and also a dealer of natural history specimens. Clench (1957: 123) wrote about him:
"His work was marred by many inaccuracies of all kinds and his attempts towards a clarification of this complex problem dwindled as the years passed, ending in brief descriptions and eventually a sales catalogue with a few "new species" described. In fairness to Maynard, however, the commercial side of his venture was not to gain profit for himself but to realize money to finance additional expeditions in quest of these mollusks in which he was so deeply interested. It seems to me that Maynard failed to grasp much of the importance of his own discoveries... Nevertheless, we owe much to Maynard for his early exploration of both the Bahama Islands and the Cayman Islands, as the specimens he collected are still the only materials available for study from many remote and inaccessible localities."
In total 248 Cerion species-level names have been proposed by Maynard, of which the type specimens were revised by Harasewych et al. (2007). It has to be said to Maynard’s credit, that the type material of nearly all his taxa has been preserved is and is now mainly in the MCZ (Boston) and USNM (Washington). Only for eight taxa neotypes had to be selected.
However, with this overwhelming number of ‘species’, one could easily ask: “what did he see that I don’t see?”. Needless to say that many of his taxa are now considered synonyms.
For a full account of his malacological work, including a biography, see Turner (1957).
References:
Clench, W.J., 1957. A catalog of the Cerionidae (Mollusca: Pulmonata). - Bulletin of the Museum of Comparative Zoology 116: 121-169.
Harasewych, M.G., Baldinger, A., Villacampa, Y. & Greenhall. P., 2007. The Cerion (Mollusca: Gastropoda: Pulmonata: Cerionidae) taxa of Charles Johnson Maynard nd their type species. - Bulletin of the Museum of Comparative Zoology 158: 367-523.
Turner, R.D., 1957. Charles Johnson Maynard and his work in malacology. - Occasional Papers on Mollusks 2 (21): 137-152.
A name is a name is a name?*
01-05-2009 08:16
Rumors say that the work of the
ICZN Secretariat
might be endangered in the (near) future by a lack of
funds. Perhaps they has to be regarded an unsuspected
victim of the current financial crisis.
This may not sound alarming, but in fact it threatens the lubricating oil of taxonomy. So a new business model might be necessary to enable continuation of this essential work.
Will individual scientists be required to pay a fee for each taxon published? Or institutions asked for a contribution related to the work of their taxonomists? What will be the side effects of a change in business model related to new taxon names?
Another rumor popped into my mind, telling that new zoological names have been on offer to the best bidder. I can’t find the source right now, but I wouldn’t be surprised if it actually happened. Speaking about scientific integrity...
Finally there is a discussion on the number of species described each year. No one seems to know, although reference is made to a paper** which gives estimates for different groups. But I think hard data may only become available when the use of Zoobank has become mandatory.
Interesting times are ahead...
* Peter Dance originally came up with this title for a presentation that was cancelled. It will now appear as a paper later this year.
**Bebber et al., 2007. Predeicting unknown species numbers using discovery curves. Proceedings Royal Society London, B 274: 1651-1658.
I have to look it up in the library. Next week, when the Queen’s Day - Liberation Day holiday period is over.
This may not sound alarming, but in fact it threatens the lubricating oil of taxonomy. So a new business model might be necessary to enable continuation of this essential work.
Will individual scientists be required to pay a fee for each taxon published? Or institutions asked for a contribution related to the work of their taxonomists? What will be the side effects of a change in business model related to new taxon names?
Another rumor popped into my mind, telling that new zoological names have been on offer to the best bidder. I can’t find the source right now, but I wouldn’t be surprised if it actually happened. Speaking about scientific integrity...
Finally there is a discussion on the number of species described each year. No one seems to know, although reference is made to a paper** which gives estimates for different groups. But I think hard data may only become available when the use of Zoobank has become mandatory.
Interesting times are ahead...
* Peter Dance originally came up with this title for a presentation that was cancelled. It will now appear as a paper later this year.
**Bebber et al., 2007. Predeicting unknown species numbers using discovery curves. Proceedings Royal Society London, B 274: 1651-1658.
I have to look it up in the library. Next week, when the Queen’s Day - Liberation Day holiday period is over.