Pleurodontidae
Preparing for dissection
10-08-2010 05:23
Yesterday, we spent a
large part of the day at the (Cincinnati) Museum to
sort out material that Francisco had brought during
his recent trip to Colombia. One of the things we
ended up doing, however, was to find a way to extract
the body from an Isomeria
species. These animals
are difficult to remove from their shells, not only
due to the constrictions in their aperture, but
mainly due to their body rapidly becoming very stiff;
even after preservation of only a few weeks in
ethanol.
From a literature search, it was not immediate evident where the retractor muscle was assumed to be attached in these specimens. Hence we decided to make a window in the last whorl.
As you don’t want to mess up a single specimen of a potentially new species, it was decided to first practice on a specimen with poor data. Tools to be used: a rotary-motortool with a diamond-tipped sewing disk, a dissecting needle, some pincers, and a laboratory spatule.
After some careful thought on where to begin and where to go, the lab was soon filled with noises that usually can be heard at the dentist. The smell of burned shell was also quite prominent.
After some time a window was opened, leaving the characteristics of the species (umbilical area, angled periphery) untouched. Time now to try to remove the body from the shell.
Due to the stiffness of the body, some poking on the foot was required to get the tissue throught the aperture. Then the body extraction could start.
In the end, the results were quite satisfying. An animal and a not too badly damaged shell.
From a literature search, it was not immediate evident where the retractor muscle was assumed to be attached in these specimens. Hence we decided to make a window in the last whorl.
As you don’t want to mess up a single specimen of a potentially new species, it was decided to first practice on a specimen with poor data. Tools to be used: a rotary-motortool with a diamond-tipped sewing disk, a dissecting needle, some pincers, and a laboratory spatule.
After some careful thought on where to begin and where to go, the lab was soon filled with noises that usually can be heard at the dentist. The smell of burned shell was also quite prominent.
After some time a window was opened, leaving the characteristics of the species (umbilical area, angled periphery) untouched. Time now to try to remove the body from the shell.
Due to the stiffness of the body, some poking on the foot was required to get the tissue throught the aperture. Then the body extraction could start.
In the end, the results were quite satisfying. An animal and a not too badly damaged shell.
Enjoying a caterpillar
14-07-2010 21:23
During a recent trip to
Cuba, Adrián González made quite a few interesting
observations. Today I share his photographs of
a Zachrysia
guanensis meeting a dead caterpillar.
Snails foraging on the ground can easily meet some decaying animals. And although they are supposed to be herbivores, sometimes they may be (temporarily?) omnivorous. According to Adrián “this Zachrysia was really enjoying the caterpillar”.
Snails foraging on the ground can easily meet some decaying animals. And although they are supposed to be herbivores, sometimes they may be (temporarily?) omnivorous. According to Adrián “this Zachrysia was really enjoying the caterpillar”.
Abnormalities in Cuban snails
06-05-2010 09:21
Adrián González kindly
sent me some interesting pictures of abnormal Cuban
land snails. Some of you may call them weird and some
consider them as ‘freaks’ which are highly valued by
collectors.
The first pictures are of Zachrysia guanensis castanea Aguayo & Jaume, 1954, from the Cuajani valley in Viñales, Piñar del Río province. This is an animal with a split in the right ocular tentacle.
The second series considers Polymita muscorum from Holguín province. Here is P. m. splendida Torre, 1950 from municipality of Frank País, Corinthia:
Interestingly, this population shows very few or none of the spots that are normal in P. muscarum.
But Adrián also found an albino form that is very common in many populations; this one is also P. m. splendida from Cano Doce, Banes in Holguín province. Note the spots on the shell typically of P. muscarum and compare them with those on the last shell in this series, which is known as P. sulphurosa flammulata Torre, 1950.
The dots in this shell may indicate a hybridization process between P. sulphurosa and P. muscarum.
Finally, within the population of P. m. splendida at Cano Doce, there is a conical shaped form, described as variety subrocheri by Carlos de la Torre in 1950 (foreground left in the next picture). It is recommended that this population is studied before their habitat is converted into pasture land.
Within this population, some abnormal (‘teratological’) shaped specimens were observed.
Alejandro Fernández, Vicente Berovides and Bernardo Reyes-Tur have made important studies about Polymita (references in the bibliography on Cuban land snails). One of the papers is by Fernández & Berovides (1995), reporting on the different subspecies of P. muscarum in Holguín province. The distribution of these forms in this province would make a more detailed study, using DNA to clarify the phylogeography of the traits, very interesting.
Thanks Adrián, for sharing this information.
Reference:
Fernández, A. & Berovides, V., 1995. Las subespecies de Polymita muscarum en Holguín (Gastropoda: Helminthoglyptidae). - Cocuyo 4: 26-28.
The first pictures are of Zachrysia guanensis castanea Aguayo & Jaume, 1954, from the Cuajani valley in Viñales, Piñar del Río province. This is an animal with a split in the right ocular tentacle.
The second series considers Polymita muscorum from Holguín province. Here is P. m. splendida Torre, 1950 from municipality of Frank País, Corinthia:
Interestingly, this population shows very few or none of the spots that are normal in P. muscarum.
But Adrián also found an albino form that is very common in many populations; this one is also P. m. splendida from Cano Doce, Banes in Holguín province. Note the spots on the shell typically of P. muscarum and compare them with those on the last shell in this series, which is known as P. sulphurosa flammulata Torre, 1950.
The dots in this shell may indicate a hybridization process between P. sulphurosa and P. muscarum.
Finally, within the population of P. m. splendida at Cano Doce, there is a conical shaped form, described as variety subrocheri by Carlos de la Torre in 1950 (foreground left in the next picture). It is recommended that this population is studied before their habitat is converted into pasture land.
Within this population, some abnormal (‘teratological’) shaped specimens were observed.
Alejandro Fernández, Vicente Berovides and Bernardo Reyes-Tur have made important studies about Polymita (references in the bibliography on Cuban land snails). One of the papers is by Fernández & Berovides (1995), reporting on the different subspecies of P. muscarum in Holguín province. The distribution of these forms in this province would make a more detailed study, using DNA to clarify the phylogeography of the traits, very interesting.
Thanks Adrián, for sharing this information.
Reference:
Fernández, A. & Berovides, V., 1995. Las subespecies de Polymita muscarum en Holguín (Gastropoda: Helminthoglyptidae). - Cocuyo 4: 26-28.
Photo of the day (90): Solaropsis
08-04-2010 14:58
Adrián González kindly
forwarded me a photograph from a Solaropsis
species. I think it
is S. cf.
solenostoma (Pfeiffer, 1852). The picture was
made by Jaime Buestán in Ecuador, Prov. Guayas,
Bucay, humid forests near río Limón, 850 m.
Interestingly, Adrián found the same species recently in Prov. Imbabura, Sanguagal, 600 m and in cold cloud forest at 1500 m in the Chontal Alto area in the same province.
Interestingly, Adrián found the same species recently in Prov. Imbabura, Sanguagal, 600 m and in cold cloud forest at 1500 m in the Chontal Alto area in the same province.
New taxa (20): Olympus
07-04-2010 20:30
Recently, Luiz Simone
published a paper on a new genus and species from the
tepui area in the Brazilian/Venezuelan border
(Simone, 2010). It is called Olympus nimbus
gen.n. sp.n. and placed
by him in the Camaenidae. The type locality is
Brazil, Amazonas, São Gabriel de Cachoeira, Pico da
Neblina, 100m. Holotype MZSP 87151.
This locality is in lowland at the base of the tepui on the Brazilian-Venezuelan border, Pico da Neblina = Cerro de Neblina. See also here and here (including links) for species from higher elevations in the same area.
The paper contains a very detailed description of the anatomy, very well illustrated with precise drawings. It is a masterpiece of morphological work.
Olympus is said to be closely related to Solaropsis, a Camaenid genus that is considered by Cuezzo (2003) to be part of the Caracolinae and by Schieleyko (2006) considered as Pleurodontidae. The taxonomy of the Neotropical “Camaenidae” is thus in disorder when only morphological and anatomical characters are used. Perhaps that additional molecular data (cf. Wade et al, 2007) may shed light on this controversy. Until then, I prefer to group the Neotropical genera as Pleurodontidae.
References:
Cuezzo, M.G., 2003. Phylogenetic analysis of the Camaenidae (Mollusca: Stylommatophora) with special emphasis on the American taxa. — Zoological Journal of the Linnean Society 138: 449-476.
Schileyko, A., 2006. Treatise on Recent terrestrial pulmonate molluscs, 13. Helicidae, Pleurodontidae, Polygyridae, Ammonitellidae, Oreohelicidae, Thysanophoridae. — Ruthenica, Supplement 2: 1795-1906.
Simone, L.R.L., 2010. A new genus and species of Camaenid from the Amazon rainforest, Brazil (Pulmonata, Helicoidea). — Journal of Conchology 40: 149-161.
Wade, C.M., C. Hudelot, A. Davison, F. Naggs & P.B. Mordan, 2007. Molecular phylogeny of the helicoid land snails (Pulmonata: Stylommatophora: Helicoidea), with special emphasis on the Camaenidae. — Journal of Molluscan Studies 73: 411-415.
This locality is in lowland at the base of the tepui on the Brazilian-Venezuelan border, Pico da Neblina = Cerro de Neblina. See also here and here (including links) for species from higher elevations in the same area.
The paper contains a very detailed description of the anatomy, very well illustrated with precise drawings. It is a masterpiece of morphological work.
Olympus is said to be closely related to Solaropsis, a Camaenid genus that is considered by Cuezzo (2003) to be part of the Caracolinae and by Schieleyko (2006) considered as Pleurodontidae. The taxonomy of the Neotropical “Camaenidae” is thus in disorder when only morphological and anatomical characters are used. Perhaps that additional molecular data (cf. Wade et al, 2007) may shed light on this controversy. Until then, I prefer to group the Neotropical genera as Pleurodontidae.
References:
Cuezzo, M.G., 2003. Phylogenetic analysis of the Camaenidae (Mollusca: Stylommatophora) with special emphasis on the American taxa. — Zoological Journal of the Linnean Society 138: 449-476.
Schileyko, A., 2006. Treatise on Recent terrestrial pulmonate molluscs, 13. Helicidae, Pleurodontidae, Polygyridae, Ammonitellidae, Oreohelicidae, Thysanophoridae. — Ruthenica, Supplement 2: 1795-1906.
Simone, L.R.L., 2010. A new genus and species of Camaenid from the Amazon rainforest, Brazil (Pulmonata, Helicoidea). — Journal of Conchology 40: 149-161.
Wade, C.M., C. Hudelot, A. Davison, F. Naggs & P.B. Mordan, 2007. Molecular phylogeny of the helicoid land snails (Pulmonata: Stylommatophora: Helicoidea), with special emphasis on the Camaenidae. — Journal of Molluscan Studies 73: 411-415.
Photo of the day (84): Coloniconcha
03-02-2010 08:54
David Robinson recently
made a trip to Dominican Republic, at the time the
earthquake hit Port-au-Prince. “The idea of
collecting specimens seemed paltry and unimportant
compared with what was going on”. Nevertheless he was
able to collect some specimens of Coloniconcha prima
Pilsbry, 1933. These
youngsters are the pic(k) of the day.
Thanks David!
Thanks David!
Coloniconcha
06-11-2009 19:19
In an
earlier
post I
mentioned a remarkable species from
Hispaniola, Coloniconcha
prima Pilsbry, 1933. At that time I
didn't know exactly to which family it belonged.
Pilsbry originally had assumed that this species
was close to Polydontes,
which is placed in
the Pleurodontidae by Schileyko (2006).
Upon dissection, I can now confirm the classification by Pilsbry. Whether the family has to be called Pleurodontidae sensu Schileyko or Camaenidae sensu Cuezzo (2003) remains a matter of debate.
The paper giving all the details is close to completion.
References:
Cuezzo, M.G., 2003. Phylogenetic analysis of the Camaenidae (Mollusca: Stylommatophora) with special emphasis on the American taxa. - Zoological Journal of the Linnean Society 138: 449-476.
Schileyko, A.A., 2006. Treatise on Recent terrestrial pulmonate molluscs, 13. Helicidae, Pleurodontidae, Polygyridae, Ammonitellidae, Oreohelicidae, Thysanophoridae. - Ruthenica, Supplement 2: 1795-1906.
Upon dissection, I can now confirm the classification by Pilsbry. Whether the family has to be called Pleurodontidae sensu Schileyko or Camaenidae sensu Cuezzo (2003) remains a matter of debate.
The paper giving all the details is close to completion.
References:
Cuezzo, M.G., 2003. Phylogenetic analysis of the Camaenidae (Mollusca: Stylommatophora) with special emphasis on the American taxa. - Zoological Journal of the Linnean Society 138: 449-476.
Schileyko, A.A., 2006. Treatise on Recent terrestrial pulmonate molluscs, 13. Helicidae, Pleurodontidae, Polygyridae, Ammonitellidae, Oreohelicidae, Thysanophoridae. - Ruthenica, Supplement 2: 1795-1906.
Photo of the day (73): Labyrinthus
23-10-2009 07:36
Another species from
the same locality, Río Arabela in northern Peru, is
this Labyrinthus
raimondii (Philippi, 1867).
These photographs are also by courtesy of Grace Montalván.
These photographs are also by courtesy of Grace Montalván.
Photo of the day (70): Isomeria
16-10-2009 21:57
Andrés Quintaro kindly
sent me some new pictures of Colombian land snails
and I’m happy to share them with you.
This is Isomeria oreas (Koch, 1845) and was photographed in Dept. Tolima, near Filandia.
This is Isomeria oreas (Koch, 1845) and was photographed in Dept. Tolima, near Filandia.
Ecuadorian snails
31-03-2009 19:25
Recently I received a mail from a French bird watcher
who had been to Ecuador. I know that bird watchers
can be ardent ‘snail watchers’ and vice versa. He
took some pictures at Rio Silanche Reserve, a patch
of tropical lowland forest at 500 m elevation on the
west side of the Andes.
It is always difficult to make an identification from a photograph only, especially if there only dorso-lateral views of the shell obscuring any details of the umbilicus, the shape of the aperture, possible dentition, etc. On the other hand, it is extremely nice to have pictures of living snails. There can’t be enough.
With all the reservations you can expect from a scientist, the final judgement is that this is most probably Strophocheilus popelarianus (Nyst, 1845).
The other picture is from some pleurodontid species. Most likely it is an Isomeria, possibly I. kolbergi (Miller).
Thanks to Vincent Mouret for the pictures and to Francisco Borrero for help with identifications.
It is always difficult to make an identification from a photograph only, especially if there only dorso-lateral views of the shell obscuring any details of the umbilicus, the shape of the aperture, possible dentition, etc. On the other hand, it is extremely nice to have pictures of living snails. There can’t be enough.
With all the reservations you can expect from a scientist, the final judgement is that this is most probably Strophocheilus popelarianus (Nyst, 1845).
The other picture is from some pleurodontid species. Most likely it is an Isomeria, possibly I. kolbergi (Miller).
Thanks to Vincent Mouret for the pictures and to Francisco Borrero for help with identifications.