nov 2008
Image tricks
30-11-2008 13:03
Don’t take this post too serious, after all it’s
Sunday. And although a scientist doesn’t have a 5-day
working week with 9am-5pm hours, there should be room
for some experimenting and creative play.
These are some pictures that I made with Image Tricks and several settings to manipulate colour, focus, distortion, style, halftone and lumine.
Viewed in another context one would call this art. But after all, science is an art.
These are some pictures that I made with Image Tricks and several settings to manipulate colour, focus, distortion, style, halftone and lumine.
Viewed in another context one would call this art. But after all, science is an art.
Taking pictures is a craft
29-11-2008 12:34
Needing several pictures to illustrate an upcoming
paper, I finally had the opportunity to make some
photographs at Naturalis. While at previous occasions
this was done at a photography room with expert
assistance of a colleague, this time it was a
provisional set-up and I was on my own.
Quickly I discovered that taking shell pictures is a real craft. You can switch on the automatic mode, but it won’t help very much. Not only the different components of the set-up have to be geared towards the object (the shell), some practical tricks appeared necessary. A difficult (because very shining) shell shows the results.
On the first picture I used a ring of TL light, which eliminated shadows but produced too much of a white ‘blob’. When I switched lights, the colour of the shell became too unnatural and I had to adapt the white balance to obtain the natural colours of the shell (picture 2-5).
Because this shell was so shining I was still not satisfied with the result and experimented with dimming the light by placing a white sheet of paper between the lamp and the shell. Picture 6 shows how the improvement looks after one side, leaving a dark shadow around the top and too much reflection at the bottom of the shell.
The result is now quite reasonable, but one final step appears to be necessary. Because it was a stand-alone set-up without connection between the camera and computer, I was unable to immediately judge the results. They looked good on the screen, but after transferral of the pictures to the computer, it was clear that one extra round is needed to improve the depth of field...
Science is not only observation, thinking and writing, but also overcoming a lot of practical hurdles.
Quickly I discovered that taking shell pictures is a real craft. You can switch on the automatic mode, but it won’t help very much. Not only the different components of the set-up have to be geared towards the object (the shell), some practical tricks appeared necessary. A difficult (because very shining) shell shows the results.
On the first picture I used a ring of TL light, which eliminated shadows but produced too much of a white ‘blob’. When I switched lights, the colour of the shell became too unnatural and I had to adapt the white balance to obtain the natural colours of the shell (picture 2-5).
Because this shell was so shining I was still not satisfied with the result and experimented with dimming the light by placing a white sheet of paper between the lamp and the shell. Picture 6 shows how the improvement looks after one side, leaving a dark shadow around the top and too much reflection at the bottom of the shell.
The result is now quite reasonable, but one final step appears to be necessary. Because it was a stand-alone set-up without connection between the camera and computer, I was unable to immediately judge the results. They looked good on the screen, but after transferral of the pictures to the computer, it was clear that one extra round is needed to improve the depth of field...
Science is not only observation, thinking and writing, but also overcoming a lot of practical hurdles.
Puzzle picture
28-11-2008 19:33
Photo by Rolf Nijsse
A puzzle picture...
No big deal, you should look for a snail, of course. While in the dark rain forest you certainly need a pair of good eyes to spot these creatures. But see this one climbing the tree covered with algae? It’s my food, stupid!
Someone spotted this specimen recently while on holiday in Peru, near Puerto Maldonado, Tambopata. It is a species of Sultana, probably Sultana sultana (Dillwyn, 1817).
It’s characterized by a orange line near the creeping sole and a dark stripe on the head. The broad and tapering tentacles are characteristic of the subfamily.
The title of this post should have read: Photo of the day (26): Sultana. The photo was kindly supplied by Herman Cremers. Thanks Herman!
Prime and remnant species
27-11-2008 21:32
An interesting concept that is part of a thesis to be
defended next week (more on it then), is that of the
distinction between ‘prime’ and ‘remnant’ species
(Gittenberger & Kokshoorn, 2008).
In several genera, there is one (sub)species that has a relatively wide range and a common occurrence. These evolutionary successful taxa may be dubbed the ‘prime’ species of a genus. In contrast, species with a relatively small distribution range might be called ‘remnant’ species. However, data on the phylogenetic relationships will be necessary to be able to differentiate between (1) recent speciation and (2) a secondary situation, with stability or decrease in range.
‘Remnant’ species may also be considered as rare, endemic species which might be of potential interest for conservation. Rabonowitz (1981) has made a classification of rarity in plants, and it is interesting to apply this here in analogy. He distinguishes seven forms of rarity in three categories: range size, habitat specificity and local abundance. His scheme is:
Two orthalicid species that spring to mind which may exemplify the concept of ‘prime’ species are Plekocheilus (Eurytus) floccosus (Orbigny, 1835) and Drymaeus (D.) expansus (Pfeiffer, 1848). They range both on the eastern slopes of the Andes, from Bolivia to Peru/Ecuador. A picture of the latter species (unfortunately, no better in stock at the moment) is here:
References:
Gittenberger, E. & Kokshoorn, B., 2008. Evolutionary inequality in Chondrina and Arianta (Gastropoda: Pulmonata): ‘prime’ and ‘remnant’ species. In: B. Kokshoorn, 2008. Resolving riddles and presenting new puzzles in Chondrinidae phylogenetics. Leiden, Ph.D. thesis: 59-64.
Rabinowitz, D., 1981. Seven forms of rarity. In: H. Synge (ed.), The biological aspects of rare plant conservation. New York, Wiley: 205-217.
In several genera, there is one (sub)species that has a relatively wide range and a common occurrence. These evolutionary successful taxa may be dubbed the ‘prime’ species of a genus. In contrast, species with a relatively small distribution range might be called ‘remnant’ species. However, data on the phylogenetic relationships will be necessary to be able to differentiate between (1) recent speciation and (2) a secondary situation, with stability or decrease in range.
‘Remnant’ species may also be considered as rare, endemic species which might be of potential interest for conservation. Rabonowitz (1981) has made a classification of rarity in plants, and it is interesting to apply this here in analogy. He distinguishes seven forms of rarity in three categories: range size, habitat specificity and local abundance. His scheme is:
| Range size
|
Habitat
specificity
|
Local abundance
|
Prime/remnant
|
| Large
|
Wide
|
Small
|
|
| Large
|
Narrow
|
Large
|
?‘Prime’
|
| Large
|
Narrow
|
Small
|
|
| Small
|
Wide
|
Large
|
|
| Small
|
Wide
|
Small
|
|
| Small*
|
Narrow*
|
Large*
|
‘Remnant’
|
| Small*
|
Narrow*
|
Small*
|
‘Remnant’
|
Two orthalicid species that spring to mind which may exemplify the concept of ‘prime’ species are Plekocheilus (Eurytus) floccosus (Orbigny, 1835) and Drymaeus (D.) expansus (Pfeiffer, 1848). They range both on the eastern slopes of the Andes, from Bolivia to Peru/Ecuador. A picture of the latter species (unfortunately, no better in stock at the moment) is here:
References:
Gittenberger, E. & Kokshoorn, B., 2008. Evolutionary inequality in Chondrina and Arianta (Gastropoda: Pulmonata): ‘prime’ and ‘remnant’ species. In: B. Kokshoorn, 2008. Resolving riddles and presenting new puzzles in Chondrinidae phylogenetics. Leiden, Ph.D. thesis: 59-64.
Rabinowitz, D., 1981. Seven forms of rarity. In: H. Synge (ed.), The biological aspects of rare plant conservation. New York, Wiley: 205-217.
New taxa (5): Annulariidae
26-11-2008 11:29
Continuing the series on new species, I realized it
be better called new taxa in order to include also
supraspecific new introduced names.
Today a number of such names, introduced by Thomas Watters for the Annulariidae. This family of land snails is huge, with about 1400 nominal taxa described of which Watters retains ca. 700 as valid species. The distribution is focussed on the Caribbean, with some groups occurring in Florida, Central American and northern South America.
From top to bottom: Blaesiospira echinus (Pfeiffer, 1864), Chrodropomartes irradians (Pfeiffer, 1852), Xenopoma hystris (Pfeiffer, 1862).
New taxa:
Tudorinae subfamily nov.
Chittypoma gen.nov. Type species: Adamsiella jarvisi Henderson, 1901
Goulidipoma gen.nov. Type species: Chondropoma callipeplum Solem, 1961
Halotudora gen.nov. Type species: Cyclostoma radiosum Morelet, 1849
Megannularia gen.nov. Type species: Turbo pulcher Wood, 1828
Samanicola gen.nov. Type species: Incertipoma nesiotes Bartsch, 1946
Saulaepoma gen.nov. Type species: Cyclostoma sauliae Sowerby, 1843
His work is a milestone for this - often considered as difficult - family, giving a new scheme for the higher taxa and references to taxa on the species level. For the latter the following data are provided: depository of types, type locality, if the type has been figured, current taxonomy, remarks, synonymy, distributional range and etymology.
The only thing I was missing is an index.
Reference:
Watters, G.T., 2006. The Caribbean land snail family Annulariidae: a revision of the higher taxa and a catalog of the species. Leiden: Backhuys Publishers, 557 + 9 unnumbered pages + appendix (3 pp.).
Today a number of such names, introduced by Thomas Watters for the Annulariidae. This family of land snails is huge, with about 1400 nominal taxa described of which Watters retains ca. 700 as valid species. The distribution is focussed on the Caribbean, with some groups occurring in Florida, Central American and northern South America.
From top to bottom: Blaesiospira echinus (Pfeiffer, 1864), Chrodropomartes irradians (Pfeiffer, 1852), Xenopoma hystris (Pfeiffer, 1862).
New taxa:
Tudorinae subfamily nov.
Chittypoma gen.nov. Type species: Adamsiella jarvisi Henderson, 1901
Goulidipoma gen.nov. Type species: Chondropoma callipeplum Solem, 1961
Halotudora gen.nov. Type species: Cyclostoma radiosum Morelet, 1849
Megannularia gen.nov. Type species: Turbo pulcher Wood, 1828
Samanicola gen.nov. Type species: Incertipoma nesiotes Bartsch, 1946
Saulaepoma gen.nov. Type species: Cyclostoma sauliae Sowerby, 1843
His work is a milestone for this - often considered as difficult - family, giving a new scheme for the higher taxa and references to taxa on the species level. For the latter the following data are provided: depository of types, type locality, if the type has been figured, current taxonomy, remarks, synonymy, distributional range and etymology.
The only thing I was missing is an index.
Reference:
Watters, G.T., 2006. The Caribbean land snail family Annulariidae: a revision of the higher taxa and a catalog of the species. Leiden: Backhuys Publishers, 557 + 9 unnumbered pages + appendix (3 pp.).
Photo of the day (25): Amphibulima
25-11-2008 13:56
Ad Hovestadt sent me a picture taken during his
recent trip to Dominica, West Indies. Although the
background is accidentally sharper than the shell,
this is probably a specimen of Amphibulima browni
Pilsbry, 1899.
It is one of those rare species that are seldomly collected, so it is fortunate to be pictured.
Thanks Ad!
Update: After examining the shell of this specimen Ad and I have come to the conclusion that it actually represents the very similar A. pardalina Guppy, 1868
It is one of those rare species that are seldomly collected, so it is fortunate to be pictured.
Thanks Ad!
Update: After examining the shell of this specimen Ad and I have come to the conclusion that it actually represents the very similar A. pardalina Guppy, 1868
Brazilian streptaxids
23-11-2008 17:32
The Streptaxidae are a family known from various
tropical regions and Barbosa et al. (2008) have now
re-evaluated a Brazilian group, the genus
Hypselartemon Wenz, 1947.
It is a nice paper, dealing with the morphology and anatomy of the few taxa placed in this genus. Formerly ascribed to Brazil and Colombia, these taxa are now wholly restricted to the former country and occur in the eastern part only.
Reference:
Barbosa, A.F., Salgado, N.C. & Santos Coelho, A.C. dos, 2008. Taxonomy, comparative morphology, and geographical distribution of the Neotropical genus Hypselartemon Wenz, 1947 (Gastropoda: Pulmonata: Streptaxidae) - Malacologia 50: 1-12.
It is a nice paper, dealing with the morphology and anatomy of the few taxa placed in this genus. Formerly ascribed to Brazil and Colombia, these taxa are now wholly restricted to the former country and occur in the eastern part only.
Reference:
Barbosa, A.F., Salgado, N.C. & Santos Coelho, A.C. dos, 2008. Taxonomy, comparative morphology, and geographical distribution of the Neotropical genus Hypselartemon Wenz, 1947 (Gastropoda: Pulmonata: Streptaxidae) - Malacologia 50: 1-12.
Eponyms, the edge between taxonomy and biohistory
22-11-2008 11:14
Taxonomists have one preference that other biologists
are missing, viz. to choose freely - within the
limits of the ICZN-rules - the name of any new taxon
they describe. Part of the rules regulate the naming
of persons and these eponyms can tell us something
about the social network of taxonomists.
Most eponyms are clearly recognizable at first glance. And often the author mentions a reason why he has chosen to name a taxon after (a) certain person(s). But not always and in the past it was not always custom to give an etymology. Moreover, besides the ‘obvious’ ones, there are ‘hidden’ eponyms. Examples of this latter category are Cyathopoma tres Van Bruggen, 2008 (named after E. Gittenberger, A.J. de Winter and I. La Croix) and Gliberti prosperi Van der Meulen, 1951 (named after the Dutch malacologist J. Voorwinde, who’s name means “they who sailed before the wind” i.e. prosperous).
There are taxonomists who have a horror of eponyms, and other who seem to be really fond of them. The ‘strict school’ wants all taxon names to reflect characteristics of the taxon or the geographical area where it was found. My personal stand is that sometimes this is preferable indeed, but sometimes it is just a pleasure to name a new taxon after an esteemed colleague or to honor the person who collected the specimens. Or to make a combination, like in the case of Van Bruggen’s eponym...
Gijs Kronenberg, to whom I’m grateful for exchanging some thoughts on this topic, will publish an updated list on the eponyms of Dutch malacologists at the occasion of the 75th anniversary of the Dutch Malacological Society in 2009.
Most eponyms are clearly recognizable at first glance. And often the author mentions a reason why he has chosen to name a taxon after (a) certain person(s). But not always and in the past it was not always custom to give an etymology. Moreover, besides the ‘obvious’ ones, there are ‘hidden’ eponyms. Examples of this latter category are Cyathopoma tres Van Bruggen, 2008 (named after E. Gittenberger, A.J. de Winter and I. La Croix) and Gliberti prosperi Van der Meulen, 1951 (named after the Dutch malacologist J. Voorwinde, who’s name means “they who sailed before the wind” i.e. prosperous).
There are taxonomists who have a horror of eponyms, and other who seem to be really fond of them. The ‘strict school’ wants all taxon names to reflect characteristics of the taxon or the geographical area where it was found. My personal stand is that sometimes this is preferable indeed, but sometimes it is just a pleasure to name a new taxon after an esteemed colleague or to honor the person who collected the specimens. Or to make a combination, like in the case of Van Bruggen’s eponym...
Gijs Kronenberg, to whom I’m grateful for exchanging some thoughts on this topic, will publish an updated list on the eponyms of Dutch malacologists at the occasion of the 75th anniversary of the Dutch Malacological Society in 2009.
Darwin's legacy
20-11-2008 15:49
Darwin’s legacy is still very vivid and doubtless
will continue to be. A recent paper by Parent et al.
(2008) reviews the colonization and diversification
of the Galápagos terrestrial fauna. Snails are one of
the groups that have diversified on this archipelago.
Of the 10 land snail genera present on the islands,
only the bulimulids show a huge radiation. Much is,
however, still unknown - not only of snails but also
of other groups - and e.g. even the sister group of
the Galápagos bulimulids has not been ascertained
till now. One of the reasons is that no reliable
molecular clock for the group is known. As a
non-vagile group, land snails are among the animals
for which many single island endemics are to be
expected. Parent & Crispi (2006) found a
combination of both within-island and between-island
speciation and the relative importance of genetic
drift and selection in within-island diversifications
of this group is not known.
While the speciation processes are affected by colonization and extinction, the geographical dynamics of the whole archipelago has to be taken into account, where change of sea levels undoubtedly created or ceased possibilities for gene flow.
The analogy with the tepui ‘islands’ in Guayana are strikingly. Perhaps I will come back at this issue later, when hopefully more phylogenetic data are known.
Incidentally I came across another paper on the Galápagos earlier this week (Estes et al., 2000). It is a detailed reconstruction of the journey of Darwin within the archipelago. Where was Darwin in the Galápagos and what did he see? Based both on bibliographic sources and revisiting the islands in the same period of the year, the authors were still able to see the geological features noted by Darwin. However, in contrast, the flora and fauna has changed considerably since the Beagle landed on the islands.
The reconstruction was possible thanks to the detailed field notes taken during that expedition and the fact that they have been preserved. Again and again, I cannot help to stress the importance of taking field notes and storing them at a place where they will be available for future scientists.
References:
Estes, G., Grant, K.T. & Grant, P.R., 2000. Darwin in Galápagos: his footsteps through the archipelago. - Notes and Records of the Royal Society London 54: 343-368.
Parent, C.E. Caccone, A. & Petren, K., 2008. Colonization and diversification of Galápagos terrestrial fauna: a phylogenetic and biographical synthesis. - Phliosopical Transactions of the Royal Society, B 363: 3347-3361.
Parent, C.E. & Crespi, B.J., 2006. Sequrntial colonization and diversification of Galápagos endemic land snail genus Bulimulus (Gastropoda, Stylommatophora). - Evolution 60: 2311-2328.
While the speciation processes are affected by colonization and extinction, the geographical dynamics of the whole archipelago has to be taken into account, where change of sea levels undoubtedly created or ceased possibilities for gene flow.
The analogy with the tepui ‘islands’ in Guayana are strikingly. Perhaps I will come back at this issue later, when hopefully more phylogenetic data are known.
Incidentally I came across another paper on the Galápagos earlier this week (Estes et al., 2000). It is a detailed reconstruction of the journey of Darwin within the archipelago. Where was Darwin in the Galápagos and what did he see? Based both on bibliographic sources and revisiting the islands in the same period of the year, the authors were still able to see the geological features noted by Darwin. However, in contrast, the flora and fauna has changed considerably since the Beagle landed on the islands.
The reconstruction was possible thanks to the detailed field notes taken during that expedition and the fact that they have been preserved. Again and again, I cannot help to stress the importance of taking field notes and storing them at a place where they will be available for future scientists.
References:
Estes, G., Grant, K.T. & Grant, P.R., 2000. Darwin in Galápagos: his footsteps through the archipelago. - Notes and Records of the Royal Society London 54: 343-368.
Parent, C.E. Caccone, A. & Petren, K., 2008. Colonization and diversification of Galápagos terrestrial fauna: a phylogenetic and biographical synthesis. - Phliosopical Transactions of the Royal Society, B 363: 3347-3361.
Parent, C.E. & Crespi, B.J., 2006. Sequrntial colonization and diversification of Galápagos endemic land snail genus Bulimulus (Gastropoda, Stylommatophora). - Evolution 60: 2311-2328.
How many Neotropical malacologists are there?
18-11-2008 16:54
No, I don’t consider myself as a Neotropical
malacologist. Rather I see myself as a Dutch
malacologist working on Neotropical snails. So, how
many truly Neotropical malacologists are there?
To find only the beginning of the answer I quickly scanned the reference work for biohistory on malacology (Coan et al. 2007). There are over 7000 names listed, of which slightly over 250 are connected to the Neotropics, i.e. either the person was born and lived in Latin America or lived part of their life there. Some remarkable numbers turned up:
Of course, there may be some easy explanations of the differences. Local malacologists with an interest in malacohistory is surely one of them. Of course, they should publish about it, preferably with accurate data (there are still many voids in Coan’s listing). Secondly, the inclusion -or not- of a name in the work of Coan et al. is clearly haphazard. But I think the peak of malacologists in Uruguay is probably also due to the existence of an active malacological society. Organisational structure may thus be considered as a third factor.
As far as I know, the regularly scheduled CLAMA congresses are not based on membership (I would opt for it if this was possible). But it would be interesting to see if the attendance during the congresses organized so far does reflect the pattern in the figures above. And how many new names would turn up. We should coddle them, because they are still too rare a species.
Reference:
Coan, E. V., A.R. Kabat & R.E. Petit. (2007). 2400 years of malacology (4th ed., rev.). American Malacological Society.
To find only the beginning of the answer I quickly scanned the reference work for biohistory on malacology (Coan et al. 2007). There are over 7000 names listed, of which slightly over 250 are connected to the Neotropics, i.e. either the person was born and lived in Latin America or lived part of their life there. Some remarkable numbers turned up:
Of course, there may be some easy explanations of the differences. Local malacologists with an interest in malacohistory is surely one of them. Of course, they should publish about it, preferably with accurate data (there are still many voids in Coan’s listing). Secondly, the inclusion -or not- of a name in the work of Coan et al. is clearly haphazard. But I think the peak of malacologists in Uruguay is probably also due to the existence of an active malacological society. Organisational structure may thus be considered as a third factor.
As far as I know, the regularly scheduled CLAMA congresses are not based on membership (I would opt for it if this was possible). But it would be interesting to see if the attendance during the congresses organized so far does reflect the pattern in the figures above. And how many new names would turn up. We should coddle them, because they are still too rare a species.
Reference:
Coan, E. V., A.R. Kabat & R.E. Petit. (2007). 2400 years of malacology (4th ed., rev.). American Malacological Society.
Photo of the day (24): Drymaeus
16-11-2008 20:04
Valentín Mogollón kindly sent me some pictures, one
of which is an as yet unidentified Drymaeus species
from eastern Peru.
The region where this beauty was photographed looks equally luxuriant.
The photos were made by Grace Montalván Naranjos.
The region where this beauty was photographed looks equally luxuriant.
The photos were made by Grace Montalván Naranjos.
Type material catalogued
10-11-2008 16:41
As always, it is a very good idea to publish a
catalogue of type material in a museum. The
initiative of three ladies to list the types from the
Zoology Museum of the University of Costa Rica
deserves special attention, as it is still one of the
few examples of publications on type depositories
from Latin American museums.
The publication mainly lists marine taxa and land snails are represented by type material of Helicina species described by Ira Richling. The accompanying photographs are of good quality, but for a colourful impression of the helicinids one should consult Richling’s papers.
Unlike many major museums in the USA en Europe, the majority of the collection in this museum is preserved in ethanol.
Reference:
Villalobos-Rojas, F., Guzmán-Mora, A.G. & Camacho-García, Y.E., 2008. Catalogue of the type material of mollusks deposited at the Zoology Museum, University of Costa Rica. - Nautilus 122: 155-165.
The publication mainly lists marine taxa and land snails are represented by type material of Helicina species described by Ira Richling. The accompanying photographs are of good quality, but for a colourful impression of the helicinids one should consult Richling’s papers.
Unlike many major museums in the USA en Europe, the majority of the collection in this museum is preserved in ethanol.
Reference:
Villalobos-Rojas, F., Guzmán-Mora, A.G. & Camacho-García, Y.E., 2008. Catalogue of the type material of mollusks deposited at the Zoology Museum, University of Costa Rica. - Nautilus 122: 155-165.
E-paper, no blogging
09-11-2008 16:07
Can we make a leap into the future? Yes we can!
The ICZN has published a proposal to allow for electronic publications of taxonomic acts in accordance with the Code. This should facilitate the exchange of literature amoung taxonomists and accelerate the progress. Is it revolutionary?
The Commission requires a registration of new taxa with Zoobank for any new name to be published validly. This site is still in prototype status and when I searched today for “Mollusca” I found only one name (Mollusca Linneaus, 1758) and 32 publications listed (all from Zootaxa, which cannot be a matter of change). So there remains some work to do before this will be fully operationally and maybe that is the reason why the Commission sets 2010 as starting date for this requirement. Nevertheless, hopefully I will be able to register my next new taxa in the proposed way.
Of course, electronic publishing doesn’t warrant that everybody can see the paper from anywhere in the world. Open access is the only answer to this. However, this would clearly oppose the business model of scientific publishers. In this respect the proposal isn’t revolutionary at all, but it may still appear to be a big leap forward.
One reassurance for those who want not only to see new publications but also like to feel them on printed paper. After all, nothing more pleasant than to have a paper in your hand (?). I suspect, however, that libraries in their classical form will remain as a source for taxonomic literature for a long time. A place also to meet people and exchange ideas. You simply cannot neglect the social side of taxonomy...
One thing for sure, even if the proposal comes into force, blogging is still not considered a valid publication. Let’s hope that this will remain so for a very long time. You shouldn’t take a blogger too serious!
The ICZN has published a proposal to allow for electronic publications of taxonomic acts in accordance with the Code. This should facilitate the exchange of literature amoung taxonomists and accelerate the progress. Is it revolutionary?
The Commission requires a registration of new taxa with Zoobank for any new name to be published validly. This site is still in prototype status and when I searched today for “Mollusca” I found only one name (Mollusca Linneaus, 1758) and 32 publications listed (all from Zootaxa, which cannot be a matter of change). So there remains some work to do before this will be fully operationally and maybe that is the reason why the Commission sets 2010 as starting date for this requirement. Nevertheless, hopefully I will be able to register my next new taxa in the proposed way.
Of course, electronic publishing doesn’t warrant that everybody can see the paper from anywhere in the world. Open access is the only answer to this. However, this would clearly oppose the business model of scientific publishers. In this respect the proposal isn’t revolutionary at all, but it may still appear to be a big leap forward.
One reassurance for those who want not only to see new publications but also like to feel them on printed paper. After all, nothing more pleasant than to have a paper in your hand (?). I suspect, however, that libraries in their classical form will remain as a source for taxonomic literature for a long time. A place also to meet people and exchange ideas. You simply cannot neglect the social side of taxonomy...
One thing for sure, even if the proposal comes into force, blogging is still not considered a valid publication. Let’s hope that this will remain so for a very long time. You shouldn’t take a blogger too serious!
What fossils can learn
06-11-2008 20:50
In a thorough paper, Hearty & Schellenberg
present the results of their chronostratigraphic work
on Cerions from the Bahamas. With their study object
they follow in the footsteps of Goodfriend and Gould,
to name just a few well known. As such that is no
story for success. I recall a co-student to do
morphometric studies on Cerion uva from the
collections of P. Wagenaar Hummelinck, only to
conclude after measuring thousands of specimens that
the uniformity of the populations on Aruba, Curacao
and Bonaire is most strikingly.
With modern techniques Hearty and Schellenberg were able to resolve stratigraphic subunits with the Holocene and late Pleistocene of fossil and living Cerion from San Salvador Island. Morphometric studies on samples spanning a 140 kyr time period revealed interglacial sequences with a trend to increasing shell size.
Their detailed study is not only a nice contribution from a geological viewpoint, it also shows that a fossil record might be necessary to reach the conclusions they were able to draw. Their time-succession shows a continuous and directional morphological change on island-wide scale. The period of greatest rate of change coincides with the onset of interglacials, which hints to the availability of a richer diet, resulting in faster growing, more globose shells. One of their working hypothesis for future studies is that ecophenotypy as an evolutionary mechanism may explain the temporal changes in shell shape.
A second study on fossils, this time from the Mediterranean, is the paper by Altaba on Balearena from Mallorca. There are some similarities: it also considers an island fauna, and also applies morphometrics. Yet there is an interesting difference in methodology. Altaba uses geometric morphometrics applying landmarks and a principal component analysis. I find his analysis more appealing.
For the analysis he uses the program PAST, which is probably better known amoung paleontologists than amoung taxonomists working on recent specimens. I found it an interesting freeware program, albeit working only under Windows. The cross-platform alternative is MorphoJ and the acquiring of landmarks can be done use ImageJ, either from photos or drawings. As usual, my preference is platform independent software.
References:
Altaba, C.R., 2007. A new genus and species of Enidae (Gastropoda: Pulmonata) from the Quartenary of the Balearctic Islands (Western Mediterranean). - Zootaxa 1595: 43-52.
Hearty, P.J. & Schellenberg, S.A., 2008. Integrated Late Quartenary chronostratigraphy for San Salvador Island, Bahamas: patterns and trends of morphological change in the land snail Cerion. Palaeo3 267: 41-58.
With modern techniques Hearty and Schellenberg were able to resolve stratigraphic subunits with the Holocene and late Pleistocene of fossil and living Cerion from San Salvador Island. Morphometric studies on samples spanning a 140 kyr time period revealed interglacial sequences with a trend to increasing shell size.
Their detailed study is not only a nice contribution from a geological viewpoint, it also shows that a fossil record might be necessary to reach the conclusions they were able to draw. Their time-succession shows a continuous and directional morphological change on island-wide scale. The period of greatest rate of change coincides with the onset of interglacials, which hints to the availability of a richer diet, resulting in faster growing, more globose shells. One of their working hypothesis for future studies is that ecophenotypy as an evolutionary mechanism may explain the temporal changes in shell shape.
A second study on fossils, this time from the Mediterranean, is the paper by Altaba on Balearena from Mallorca. There are some similarities: it also considers an island fauna, and also applies morphometrics. Yet there is an interesting difference in methodology. Altaba uses geometric morphometrics applying landmarks and a principal component analysis. I find his analysis more appealing.
For the analysis he uses the program PAST, which is probably better known amoung paleontologists than amoung taxonomists working on recent specimens. I found it an interesting freeware program, albeit working only under Windows. The cross-platform alternative is MorphoJ and the acquiring of landmarks can be done use ImageJ, either from photos or drawings. As usual, my preference is platform independent software.
References:
Altaba, C.R., 2007. A new genus and species of Enidae (Gastropoda: Pulmonata) from the Quartenary of the Balearctic Islands (Western Mediterranean). - Zootaxa 1595: 43-52.
Hearty, P.J. & Schellenberg, S.A., 2008. Integrated Late Quartenary chronostratigraphy for San Salvador Island, Bahamas: patterns and trends of morphological change in the land snail Cerion. Palaeo3 267: 41-58.
New species (4): Brazilian Simpulopsis
05-11-2008 21:53
Speaking about lagging behind... When dealing with
the new species described from the Neotropics I have
to catch up from the past. So I intend to cover all
species since I started this blog in December 2006
and all Orthalicidae (sensu lato) since
my work in the
’70s.
The first taxa to be covered are some Simpulopsis species described from Brazil by Silva & Thomé in 2006. The two new species have both been found in Rio Grande do Sul, São Francisco de Paula, Biological station Pro-Mata.
Simpulopsis promentensis Silva & Thomé, 2006; holotype MCP 8674.
Simpulopsis gomesae Silva & Thomé, 2006; holotype MCP 8701.
Given the fact that Thomé’s group has been discontinued, it is unclear to me what happened with the collection. I assume that it is still being kept at the Pontifícia Universidade de Rio Grande do Sul.
Reference:
Silva, L.F. da & Thomé, J.W., 2006. Duas novas espécies de Simpulopsis (Gastropoda, Bulimulidae) para o Rio Grande do Sul, Brasil. - Iheringia, Zool. 96: 185-196.
The first taxa to be covered are some Simpulopsis species described from Brazil by Silva & Thomé in 2006. The two new species have both been found in Rio Grande do Sul, São Francisco de Paula, Biological station Pro-Mata.
Simpulopsis promentensis Silva & Thomé, 2006; holotype MCP 8674.
Simpulopsis gomesae Silva & Thomé, 2006; holotype MCP 8701.
Given the fact that Thomé’s group has been discontinued, it is unclear to me what happened with the collection. I assume that it is still being kept at the Pontifícia Universidade de Rio Grande do Sul.
Reference:
Silva, L.F. da & Thomé, J.W., 2006. Duas novas espécies de Simpulopsis (Gastropoda, Bulimulidae) para o Rio Grande do Sul, Brasil. - Iheringia, Zool. 96: 185-196.
Going North? At snail's pace
04-11-2008 20:50
Science journalists usually have a good sense of
appealing news. This week a brief article in my
newspaper draw my attention to an upcoming paper by
Devictor et al. in the Proceedings of the Royal
Society B, december 2008. The caption is: French
birds breed more northerly but the climate [change]
is faster.
We have read more often about the changes in the fauna and flora due to the warming of the climate of course. Some are good and (most) others are bad. So far I haven’t read much about snails; most is about plants, insects and birds. Anyone busy sorting out the effects on snails?
A quick search in Scholar shows that Devictor has a track record on the subject. Incidentally a precursor to the same paper can be found under the title “French birds lag behind climate warming”, already posted on 29 October 2007 in Nature Precedings. The basis of the paper is the Community Temperature Index, a measure calculated as the average of individual species temperature index (STI) per assemblage on a site. CTIs are then determined by the long term average temperature experienced by breeding birds over their (European) range. These can be calculated from the Worldclim database, taking the average temperature during the breeding season and coupling these data to spatial distribution data.
The effect of climate change on shifts in flora and fauna in the Neotropic/Nearctic region is not readily in the news here. But my guess would be that a similar phenomenon occurs in Mexico and the USA. Is this effect also noticeable in the ranges of land snails? Could it perhaps be measured analogous to the way briefly summarized for birds above?
Not sure if there any data exist on the occurrences of species assemblages of land snails in southern USA. I remember to have seen a map with grids somewhere, but don’t recall where. Anyway, if the snails go North they will surely lag behind the climate warming. At a snail’s pace...
We have read more often about the changes in the fauna and flora due to the warming of the climate of course. Some are good and (most) others are bad. So far I haven’t read much about snails; most is about plants, insects and birds. Anyone busy sorting out the effects on snails?
A quick search in Scholar shows that Devictor has a track record on the subject. Incidentally a precursor to the same paper can be found under the title “French birds lag behind climate warming”, already posted on 29 October 2007 in Nature Precedings. The basis of the paper is the Community Temperature Index, a measure calculated as the average of individual species temperature index (STI) per assemblage on a site. CTIs are then determined by the long term average temperature experienced by breeding birds over their (European) range. These can be calculated from the Worldclim database, taking the average temperature during the breeding season and coupling these data to spatial distribution data.
The effect of climate change on shifts in flora and fauna in the Neotropic/Nearctic region is not readily in the news here. But my guess would be that a similar phenomenon occurs in Mexico and the USA. Is this effect also noticeable in the ranges of land snails? Could it perhaps be measured analogous to the way briefly summarized for birds above?
Not sure if there any data exist on the occurrences of species assemblages of land snails in southern USA. I remember to have seen a map with grids somewhere, but don’t recall where. Anyway, if the snails go North they will surely lag behind the climate warming. At a snail’s pace...
Photo of the day (23): Placostylus
04-11-2008 16:34
It is actually not a Neotropical land snail, but
until now is considered to belong to the same
superfamily Orthalicoidea sensu lato. Although
the
confusion
still not has been solved adequately, I do follow the
opinion of Eike Neubert and consider the
Placostylidae as a separate family but related to the
Neotropical orthalicids.
While several of these giants are endangered and some might be extinct, I will highlight species of which I have pictures of live animals. The first one is Placostylus bivaricosus (Gaskoin, 1855) from Lord Howe Island off the eastern coast of Australia.
These snails are ground dwellers, living in the leaf litter of the forest. They are vulnerable to disturbance and are predated, especially the juveniles, by rats and birds.
This species can reach shell heights of up to 70 mm and is endemic to the island. Although is was “abundant” around 1900 (according to Pilsbry, Man. Conch.), it is now considered nearly extinct.
While several of these giants are endangered and some might be extinct, I will highlight species of which I have pictures of live animals. The first one is Placostylus bivaricosus (Gaskoin, 1855) from Lord Howe Island off the eastern coast of Australia.
These snails are ground dwellers, living in the leaf litter of the forest. They are vulnerable to disturbance and are predated, especially the juveniles, by rats and birds.
This species can reach shell heights of up to 70 mm and is endemic to the island. Although is was “abundant” around 1900 (according to Pilsbry, Man. Conch.), it is now considered nearly extinct.