Europe
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.
MegaLab
26-04-2009 19:13
Last week the Dutch site of the European
project
Evolution MegaLab
went live. It follows the idea that everybody can
observe evolution in his own backyard. All you have
to do is to count the number and type of
Cepaea
nemoralis
and
C.
hortensis.
When you add these data on the website, they are
automatically compared with observations from the
past (for Dutch records the collections of the Leiden
and Amsterdam museum are used).
This morning, a very light rain moistened my garden after a quite long period of dry weather. When I looked outside I found a number of snails in my backyard crawling on the vegetation. There were quite a number of Cornu aspersum - which I had noticed already by the gnawing of several plants. In total I could find 6 adult specimens of Cepaea nemoralis.
When I entered the data on the site, it appeared that no observations had been made in the past within 5 kms of my house. Also, no other recent observations had been entered in the database.
When I made an evening stroll through the village, I came across another population. Here the snails had moved into trees among herbaceous vegetation.
The website is open till September. Then all pan-European data will be analyzed and a publication will be written by all national coordinators.
This morning, a very light rain moistened my garden after a quite long period of dry weather. When I looked outside I found a number of snails in my backyard crawling on the vegetation. There were quite a number of Cornu aspersum - which I had noticed already by the gnawing of several plants. In total I could find 6 adult specimens of Cepaea nemoralis.
When I entered the data on the site, it appeared that no observations had been made in the past within 5 kms of my house. Also, no other recent observations had been entered in the database.
When I made an evening stroll through the village, I came across another population. Here the snails had moved into trees among herbaceous vegetation.
The website is open till September. Then all pan-European data will be analyzed and a publication will be written by all national coordinators.
In Czech and some snailing
25-08-2008 22:11
The past two weeks were family holidays, this time in
Czech. Discounting days in Prague and for traveling,
I had not much "field time" but did spend quite some
time on preparing an upcoming presentation.
In the central part of the country, near Bílkovice, I found a specimen of Arianta arbustorum on Urtica sp. during a walk. It was a sunny day and no other snails were found. But during an evening stroll near the same place after a drizzling day, snails were out and abundant. Helix pomatia , with light grey animals, and Arianta arbustorum with black bodies. Alas, no camera ready...
Later, in the eastern part of the country, two specimens of Lehmannia marginata were spotted on a rock face in Orlické National Park after a rainy day. The same species was found some days later when we were in Jeseniky National Park. Finally, two empty shells of Discus sp. were found when walking nearby Pastviny.
Not much, but after all, it was holidays :-)
In the central part of the country, near Bílkovice, I found a specimen of Arianta arbustorum on Urtica sp. during a walk. It was a sunny day and no other snails were found. But during an evening stroll near the same place after a drizzling day, snails were out and abundant. Helix pomatia , with light grey animals, and Arianta arbustorum with black bodies. Alas, no camera ready...
Later, in the eastern part of the country, two specimens of Lehmannia marginata were spotted on a rock face in Orlické National Park after a rainy day. The same species was found some days later when we were in Jeseniky National Park. Finally, two empty shells of Discus sp. were found when walking nearby Pastviny.
Not much, but after all, it was holidays :-)
Another garden slug, new to science
14-07-2008 07:55
Incidentally the morning post brought me another
piece of European malacological news. Selenochlamys
ysbryda (Trigonochlamydidae) was discovered in Wales.
It is an eyeless species that probably originates
from caves and is supposed to be introduced in plant
pots. The radula shows that it is carnivorous and the
species is reported to feed on earthworms.
Thanks Carl, for sending me the link.
Update: the paper by Rowson & Symondson describing the new species can be found in Journal of Conchology 39: 537-552.
Thanks Carl, for sending me the link.
Update: the paper by Rowson & Symondson describing the new species can be found in Journal of Conchology 39: 537-552.
Garden slug
13-07-2008 15:24
This time a change of focus out of the Neotropics.
While doing some gardening, this reddish-brown Arion ater (L., 1758) came to light. This omnivorous species can also attack living plants although it is said to feed mostly on dedritus. I found it when I removed a Berberis sp., only a single specimen.
While doing some gardening, this reddish-brown Arion ater (L., 1758) came to light. This omnivorous species can also attack living plants although it is said to feed mostly on dedritus. I found it when I removed a Berberis sp., only a single specimen.
Euromalac2008
06-05-2008 21:44
Not a Neotropical subject per sé, but I do want to
draw your attention that the 5th Congress of the
European Malacological Societies will be held from
2-6 September in Ponta Delgada, San Miguel, Azores.
One of the keynote speakers is Robert Cameron on
'Time, space and very slow motion: patterns in the
diversity of snails'. An intriguing title that sounds
very promising...
As there is no travel budget at Naturalis for associate researchers I will not attend, but still it is interesting to know this upcoming gathering. Full details can be found on the congress website.
As there is no travel budget at Naturalis for associate researchers I will not attend, but still it is interesting to know this upcoming gathering. Full details can be found on the congress website.
Holiday time
29-07-2007 11:51
One week off, this time
in France and no requests for collecting this time.
We are in the Loire region and I'm not expecting any
interesting species here. Besides, I don't know
anything about the French malacofauna... Oops! So far
I only saw many Arion (A.
rufus?) and
one Limax species.
Arion in love
Before we left, Frank Köhler very kindly sent me the proofs of his forthcoming paper on the types of Bulimulinae in the Berlin museum. He correctly notes that this collection has been virtually unaccessible since 1945, until the reunion of Germany in 1990. Back in the '70s I studied many types in European museums, but not those of the Humboldt Museum. It was therefore a big surprise to see the list of types from authors like e.g. Martens, Albers, Dunker, Dohrn, Strebel and Pfeiffer, with also material originating from the Cuming collection well represented and described by e.g. Sowerby, Preston and Reeve. All the species are well documented and figured, with most of them have an extensive annotation. This is a very useful and important paper!
Some weeks ago I accidentally saw the website of the Los Cedros Cloud Forest Reserve in northwestern Ecuador. A very interesting area, with an impressive biodiversity. Today I contacted the coordinator and learned that the malacofauna is still unknown, although he noted "there are three larger species, some medium and small. We have riverine crabs and a rat specializing in eating them". It would be nice to go there, perhaps together with others interested in cloud forest snails.
This is the picture that provoked my interest. It looks like a Plekocheilus species. Beautiful photograph...
Arion in love
Before we left, Frank Köhler very kindly sent me the proofs of his forthcoming paper on the types of Bulimulinae in the Berlin museum. He correctly notes that this collection has been virtually unaccessible since 1945, until the reunion of Germany in 1990. Back in the '70s I studied many types in European museums, but not those of the Humboldt Museum. It was therefore a big surprise to see the list of types from authors like e.g. Martens, Albers, Dunker, Dohrn, Strebel and Pfeiffer, with also material originating from the Cuming collection well represented and described by e.g. Sowerby, Preston and Reeve. All the species are well documented and figured, with most of them have an extensive annotation. This is a very useful and important paper!
Some weeks ago I accidentally saw the website of the Los Cedros Cloud Forest Reserve in northwestern Ecuador. A very interesting area, with an impressive biodiversity. Today I contacted the coordinator and learned that the malacofauna is still unknown, although he noted "there are three larger species, some medium and small. We have riverine crabs and a rat specializing in eating them". It would be nice to go there, perhaps together with others interested in cloud forest snails.
This is the picture that provoked my interest. It looks like a Plekocheilus species. Beautiful photograph...
Hunting for...snails
07-05-2007 20:56
Last week I was in
Italy, Sicily for a holiday. As I like to collect
snails during my holidays - even if they're not in
the Neotropics :-) - I offered to do some hunting for
a friend. He said "Clausiliidae are to be found in
the western part of Sicily, where there are
calcareous rocks, but not in the eastern part where
there is volcanic soil". So my hope for happy snail
hunting was not very high as we hired a house in the
south-east near Syracusa. But as we hired a car too I
thought "we'll drive to the west".
Once on Sicily it quickly turned out that distances are large and roads in the south are busy and small. As a consequence travelling takes time! Since my family was not up for an all-malacology holiday I had to compromise. But as soon as we set out on the first day for a trip to a nature reserve near Noto I found the first snails (though no Clausiliidae).
A few days later when we visited the Necrópoli di Pantálica, I found my first clausiliids. Later on in the week I took a whole day to tour the southeast and to collect. Despite the warning of my friend there were ample opportunities to find snails :-))
A list of localities can be found here. They are mapped with Google Earth (labels in Dutch)
During the evenings I found some time to fiddle with the sequencing results. Still on the lower side of the learning curve, I'm afraid.
Once on Sicily it quickly turned out that distances are large and roads in the south are busy and small. As a consequence travelling takes time! Since my family was not up for an all-malacology holiday I had to compromise. But as soon as we set out on the first day for a trip to a nature reserve near Noto I found the first snails (though no Clausiliidae).
A few days later when we visited the Necrópoli di Pantálica, I found my first clausiliids. Later on in the week I took a whole day to tour the southeast and to collect. Despite the warning of my friend there were ample opportunities to find snails :-))
A list of localities can be found here. They are mapped with Google Earth (labels in Dutch)
During the evenings I found some time to fiddle with the sequencing results. Still on the lower side of the learning curve, I'm afraid.