Achatina
Manna from heaven?
12-10-2010 07:37
The Lissachatina
saga
continues... Sadly,
but seemingly inevitable. This time in a place
where it may remain totally out of control.
Pictures that I received from Colombian sources, show a flourishing population in Colombia, Dept. Putumayo, Puerto Asis. As this is at the border of Ecuador, and no records for Lissachatina are known for northern localities at the eastern side of the Andes in Colombia, it seems probable that these snails have been “imported” from Ecuador.
To the poor inhibatants of this area, the sudden appearance of these snails is perhaps perceived like manna from heaven. Big bulky snails, ready to eat and use their mucus. Perhaps they are good for making some money too....
Little they know of the damage that is in store for them in their fields. Of the health risks they have to endure when one of the snails is infected.
And although the authorities have been informed, this area is way out of their attention. Slowly, but steadily, this plague will disperse.
Pictures that I received from Colombian sources, show a flourishing population in Colombia, Dept. Putumayo, Puerto Asis. As this is at the border of Ecuador, and no records for Lissachatina are known for northern localities at the eastern side of the Andes in Colombia, it seems probable that these snails have been “imported” from Ecuador.
To the poor inhibatants of this area, the sudden appearance of these snails is perhaps perceived like manna from heaven. Big bulky snails, ready to eat and use their mucus. Perhaps they are good for making some money too....
Little they know of the damage that is in store for them in their fields. Of the health risks they have to endure when one of the snails is infected.
And although the authorities have been informed, this area is way out of their attention. Slowly, but steadily, this plague will disperse.
Another find of Lissachatina
30-06-2010 18:52
Today a new record
of
Lissachatina fulica was reported by Herman Cremers, a
colleague, who spotted this species during his
holidays in Ecuador.
The snail was found In Prov. Napo, Tena, Lodge “Casa del Suizo” along the Napo river. As it was found in the newly decorated garden, it may have been transported with horticultural material. But other sources cannot be excluded a priori.
As far as I know, this is the first record of this species on the eastern side of the Andes in Ecuador.
The snail was found In Prov. Napo, Tena, Lodge “Casa del Suizo” along the Napo river. As it was found in the newly decorated garden, it may have been transported with horticultural material. But other sources cannot be excluded a priori.
As far as I know, this is the first record of this species on the eastern side of the Andes in Ecuador.
New records for Lissachatina in South America
08-06-2010 08:05
Since my last
post on a
new record for Lissachatina fulica
in South America, less
than two months have passed. This time, two new
records have to be mentioned, which may not be
totally unrelated but at least involve two new
countries. They have to be added on the list of
affected ones that unfortunately grows and grows...
The first record is Paraguay, Dept. Misiones, Ayolas, where the species was spotted by Ulf Drechsel in March 2010. This finding is documented on the PyBio website. More on this website in a following post.
This record comes several months after Gabriela Cuezzo found the same species in Argentina, Prov. Misiones, Porto Iguazú (Cuezzo, pers. commun.; in press). This is ca. 300 km NE of Ayolas, but along the same Río Paraná. It is not more than a wild guess, but this river might have acted as a route of dispersal in this case.
The first record is Paraguay, Dept. Misiones, Ayolas, where the species was spotted by Ulf Drechsel in March 2010. This finding is documented on the PyBio website. More on this website in a following post.
This record comes several months after Gabriela Cuezzo found the same species in Argentina, Prov. Misiones, Porto Iguazú (Cuezzo, pers. commun.; in press). This is ca. 300 km NE of Ayolas, but along the same Río Paraná. It is not more than a wild guess, but this river might have acted as a route of dispersal in this case.
A new record of Lissachatina in Ecuador
29-04-2010 20:33
Thanks to Adrián
González, it is now possible to document an
introduction of Lissachatina fulica
into an area hitherto
not affected by this species.
During a recent trip to the Chical-Quinyul area in Prov. Carchi, northern Ecuador, he found this specimen (see picture).
When he asked the owner of the locality where Adrián collected it, the guy told him that a while ago he brought about hundred plants from Santo Domingo de los Tsáchilas (formerly known as Santo Domingo de los Colorados) in Prov. Pichincha. This is a known occurrence for Lissachatina fulica (see Correoso, 2010) and snails probably were transported as eggs or juveniles. The owner didn’t want to kill the snail (he wanted to keep it as a pet) nor to let Adrián scrutinize the property for more specimens.
It is expected that in this area an outbreak may occur in the (most likely) case that there is no further intervention by officials. As a consequence, the local snail fauna - with flourishing populations of Drymaeus - could be seriously affected. Monitoring of this new occurrence is thus highly recommended.
This case is also a clear illustration of a pathway described by Cowie & Robinson (2003) in general and Cowie et al. (2008) for the horticultural industry.
References:
Cowie, R.H. & Robinson, D.G., 2003. Pathways of introduction of nonindigenous land and freshwater snails and slugs. In Ruiz, G. & Carlton, J.T. (Eds.), Invasive species: vectors and management strategies. Washington DC: Island Press: 93-122.
Cowie, R.H., Hayes, K.H., Tran, C.T. & Meyer, W.M., 2008. The horticultural industry as a vector of alien snails and slugs: widespread invasions in Hawaii. - International Journal of Pest Management 54: 267-276.
During a recent trip to the Chical-Quinyul area in Prov. Carchi, northern Ecuador, he found this specimen (see picture).
When he asked the owner of the locality where Adrián collected it, the guy told him that a while ago he brought about hundred plants from Santo Domingo de los Tsáchilas (formerly known as Santo Domingo de los Colorados) in Prov. Pichincha. This is a known occurrence for Lissachatina fulica (see Correoso, 2010) and snails probably were transported as eggs or juveniles. The owner didn’t want to kill the snail (he wanted to keep it as a pet) nor to let Adrián scrutinize the property for more specimens.
It is expected that in this area an outbreak may occur in the (most likely) case that there is no further intervention by officials. As a consequence, the local snail fauna - with flourishing populations of Drymaeus - could be seriously affected. Monitoring of this new occurrence is thus highly recommended.
This case is also a clear illustration of a pathway described by Cowie & Robinson (2003) in general and Cowie et al. (2008) for the horticultural industry.
References:
Cowie, R.H. & Robinson, D.G., 2003. Pathways of introduction of nonindigenous land and freshwater snails and slugs. In Ruiz, G. & Carlton, J.T. (Eds.), Invasive species: vectors and management strategies. Washington DC: Island Press: 93-122.
Cowie, R.H., Hayes, K.H., Tran, C.T. & Meyer, W.M., 2008. The horticultural industry as a vector of alien snails and slugs: widespread invasions in Hawaii. - International Journal of Pest Management 54: 267-276.
...and in Florida
23-04-2010 19:26
Lissachatina
fulica hit
the press also in Florida. David Robinson sent me a
link to the following newspaper:
The USDA found out because some people ended up in hospital, one of them with suspected cerebral angiostrongyliasis, after they had been fed with liquid from live snails. This was done during a African religious cult meeting.
“Always drama!” David said and right he is when it comes to this species.
The USDA found out because some people ended up in hospital, one of them with suspected cerebral angiostrongyliasis, after they had been fed with liquid from live snails. This was done during a African religious cult meeting.
“Always drama!” David said and right he is when it comes to this species.
More on Lissachatina in Ecuador
22-04-2010 20:02
Previously reports on
the occurrence of Lissachatina fulica in Ecuador were
based on a few observations and the assumption that
this species was far more spread into the country.
This assumption is now supported by new records which
have been documented by Modest Correoso (Correoso,
2010).
The localities are all on the western side of the Andes. Some of them were found in protected areas, like this picture documents.
In his paper, Correoso has also made a modelling of the potential distribution based on the known occurrences and SDM software.
Reference:
Correoso, M., 2009 [2010]. Modelación y distribución de Lissachatina fulica (Gastropoda, Achatinidae) en Ecuador. Potenciales impactos ambietales y sanitarios. - Revista Geospacial, Quito, Nov. 2009: 79-90.
The localities are all on the western side of the Andes. Some of them were found in protected areas, like this picture documents.
In his paper, Correoso has also made a modelling of the potential distribution based on the known occurrences and SDM software.
Reference:
Correoso, M., 2009 [2010]. Modelación y distribución de Lissachatina fulica (Gastropoda, Achatinidae) en Ecuador. Potenciales impactos ambietales y sanitarios. - Revista Geospacial, Quito, Nov. 2009: 79-90.
Biology of Lissachatina in Brazil
02-02-2010 21:42
Lissachatina
fulica is a
well-known pest now in South America (Borrero et al.,
2009). Studies on its biology, however, are
relatively scarce and especially the influence of
climatic variables and human density on growth and
condition of this species.
Albuquerque et al. (2009) studied populations in Brazil, Bahia, Lauro de Freitas. They collected samples of the snails and took measurements of shell height and total weight as proxy for condition. Five environmental variables were considered: temperature range, mean temperature, humidity, precipitation and human population density.
The results show that humidity had a significant influence on length and weight, and temperature was the only significant factor that influenced condition. Partial regression showed that the influence of human population density partially overlapped the climatic factors.
References:
Albuquerque, F.S., Peso-Aguiar, M.C., Assuncao-Albuquerque, M.J.T. & Galvez, L., 2009. Do climate variables and human density affect Achatina fulica (Bowditch) (Gastropoda: Pulmonata) shell length, total weight and condition factor? - Brazilian Journal of Biology 69: 879-885.
Borrero, F.J., Breure, A.S.H., Christensen, C., Correoso, M. & Mogollón Avila, V., 2009. Into the Andes: three new introductions of Lissachatina fulica (Gastropoda, Achatinidae) and its potential distribution in South America. - Tentacle 17: 6-8.
Albuquerque et al. (2009) studied populations in Brazil, Bahia, Lauro de Freitas. They collected samples of the snails and took measurements of shell height and total weight as proxy for condition. Five environmental variables were considered: temperature range, mean temperature, humidity, precipitation and human population density.
The results show that humidity had a significant influence on length and weight, and temperature was the only significant factor that influenced condition. Partial regression showed that the influence of human population density partially overlapped the climatic factors.
References:
Albuquerque, F.S., Peso-Aguiar, M.C., Assuncao-Albuquerque, M.J.T. & Galvez, L., 2009. Do climate variables and human density affect Achatina fulica (Bowditch) (Gastropoda: Pulmonata) shell length, total weight and condition factor? - Brazilian Journal of Biology 69: 879-885.
Borrero, F.J., Breure, A.S.H., Christensen, C., Correoso, M. & Mogollón Avila, V., 2009. Into the Andes: three new introductions of Lissachatina fulica (Gastropoda, Achatinidae) and its potential distribution in South America. - Tentacle 17: 6-8.
The tail of a snail: more on Achatina
08-07-2008 07:17
Some snails have longer tails than others, especially
if they are so slimy like Achatina fulica is. But
first a note on taxonomy before we dive further into
the Neotropical story of it's distribution.
Fontanilla et al. (2007) reported on phylogenetic work with Achatina fulica and came to the conclusion that it should taxonomically designated Lissachatina fulica. There is a second species from East Africa which belongs to this genus (Fontanilla, pers. comm.). The interesting thing is that they found that all globally dispersed populations originate from a single haplotype, originating from East Africa.
Modesto Correoso, the only person who is doing serious work on land snails in Ecuador, kindly drew my attention to the fact that in 2005 he purchased some specimens of Lissachatina fulica on a market in Esmeraldas (northwestern Ecuador) and this fact was picked up by a journalist of the newspaper El Comercio.
This was evidently the source of the reference I wrote about last week. Later, Correoso wrote a paper in a technical bulletin of a local institution. Unfortunately this has escaped the attention of the scientific community, but I like to give credits to the person who deserves them.
So we might think that the story ends here. Just an unfortunate introduction of a species that has been more or less officially reported on. Children who have fun with it as pets and some people who are earning money with it.
But like in any good detective, the next, unexpected plot is just one page away...
The article in the newspaper was mentioned on a discussion forum on aquaculture. And from there the trail leads to Venezuela. Again. Because back in 1997, Rafael Martinez found already some shells near Caracas and reported on them. Not sure what happened exactly, but his paper gives the impression that this seemed a non-established population. However, from this blog entry it may be clear that L. fulica has now reached a pest status several hundreds kilometers west of the locality reported on by Martinez. So it is evident that the species has become well established in Venezuela, but to what extent is unclear at the moment.
This is certainly not a soap series, but I'm afraid I have to say: to be continued...
Update: Barbados is another place where L. fulica has been established, according to this blog. It is said to have entered the island through the port. Barbados has spent an estimated US$ 500,000 over the past eight years in an effort to eradicate the Giant African Snail that has been infesting crops in countries across the Caribbean.
Some of the comments to this blogpost:
"We are not the first country to be infested. The GAS have been on a world tour since leaving east Africa two centuries ago. It was only a matter of time before they reached our shores. It has been found that hand collecting is the best way to do away with them however you then have to kill them. Immersion in salt water doesn’t work too well and the odor produced is not pleasant. One test found that there was an 85% survival rate after 48 hours of soaking. Burning works but stinks. Same for boiling. The surest method is to make sure that the shell is well broken. I propose that the Min of Ag distribute appropriately coloured and stenciled plastic bags that homeowners can put out with the garbage. At the dump they can easily be sorted out, run through a crusher and buried in a deep trench.
When to collect them. Don’t waste your time if it hasn’t rained for 2 or 3 days but if it rains off and on and is overcast much of the day the snails will be out foraging. During the rainy season you can usually go out at 5 p.m. and collect several hundred before 6:30 p.m. If you go out at 5 a.m. you will likely be able to collect 6 to 700 per hour through to 8 a.m. when you will no longer find enough to warrant the effort. I roam over 2 acres of land every morning and some evenings. My best day I collected 3,000. For the month of November my total was 42,000. Since then the dry season has yielded an average of 15,000 per month."
According to Pestalert, this snail is besides Guadeloupe, Martinique and Barbados, also known from St. Lucia.
References:
Correoso, M. (2006). Estrategia preliminar para evaluar y erradicar Achatina fulica (Gastropoda: Achatineaceae) en Ecuador. Boletim Técnico IASA, Serie Zoológica, 2: 45-52.
Fontanilla, I. K., Hudelot, C., Naggs, F. & Wade, C.M. (2007). Achatina fulica: its molecular phylogeny and genetic variation in global populations. http://www.malacsoc.org.uk/The_Malacologist/BULL48/forum48.htm. Re-published: Abstracts World Congress of Malacology, Antwerp, 15-20 July 2007: 63.
Martinez, R. & Martinez, E. (1997). Nota acerca de la Achatina (Lissachatina) fulica (Bowdich, 1822). Peligroso caracol africano (Pulmonata-Achatinidae) introducido en Venezuela. Acta Biologica Venezuelica, 17: 37-40.
Fontanilla et al. (2007) reported on phylogenetic work with Achatina fulica and came to the conclusion that it should taxonomically designated Lissachatina fulica. There is a second species from East Africa which belongs to this genus (Fontanilla, pers. comm.). The interesting thing is that they found that all globally dispersed populations originate from a single haplotype, originating from East Africa.
Modesto Correoso, the only person who is doing serious work on land snails in Ecuador, kindly drew my attention to the fact that in 2005 he purchased some specimens of Lissachatina fulica on a market in Esmeraldas (northwestern Ecuador) and this fact was picked up by a journalist of the newspaper El Comercio.
This was evidently the source of the reference I wrote about last week. Later, Correoso wrote a paper in a technical bulletin of a local institution. Unfortunately this has escaped the attention of the scientific community, but I like to give credits to the person who deserves them.
So we might think that the story ends here. Just an unfortunate introduction of a species that has been more or less officially reported on. Children who have fun with it as pets and some people who are earning money with it.
But like in any good detective, the next, unexpected plot is just one page away...
The article in the newspaper was mentioned on a discussion forum on aquaculture. And from there the trail leads to Venezuela. Again. Because back in 1997, Rafael Martinez found already some shells near Caracas and reported on them. Not sure what happened exactly, but his paper gives the impression that this seemed a non-established population. However, from this blog entry it may be clear that L. fulica has now reached a pest status several hundreds kilometers west of the locality reported on by Martinez. So it is evident that the species has become well established in Venezuela, but to what extent is unclear at the moment.
This is certainly not a soap series, but I'm afraid I have to say: to be continued...
Update: Barbados is another place where L. fulica has been established, according to this blog. It is said to have entered the island through the port. Barbados has spent an estimated US$ 500,000 over the past eight years in an effort to eradicate the Giant African Snail that has been infesting crops in countries across the Caribbean.
Some of the comments to this blogpost:
"We are not the first country to be infested. The GAS have been on a world tour since leaving east Africa two centuries ago. It was only a matter of time before they reached our shores. It has been found that hand collecting is the best way to do away with them however you then have to kill them. Immersion in salt water doesn’t work too well and the odor produced is not pleasant. One test found that there was an 85% survival rate after 48 hours of soaking. Burning works but stinks. Same for boiling. The surest method is to make sure that the shell is well broken. I propose that the Min of Ag distribute appropriately coloured and stenciled plastic bags that homeowners can put out with the garbage. At the dump they can easily be sorted out, run through a crusher and buried in a deep trench.
When to collect them. Don’t waste your time if it hasn’t rained for 2 or 3 days but if it rains off and on and is overcast much of the day the snails will be out foraging. During the rainy season you can usually go out at 5 p.m. and collect several hundred before 6:30 p.m. If you go out at 5 a.m. you will likely be able to collect 6 to 700 per hour through to 8 a.m. when you will no longer find enough to warrant the effort. I roam over 2 acres of land every morning and some evenings. My best day I collected 3,000. For the month of November my total was 42,000. Since then the dry season has yielded an average of 15,000 per month."
According to Pestalert, this snail is besides Guadeloupe, Martinique and Barbados, also known from St. Lucia.
References:
Correoso, M. (2006). Estrategia preliminar para evaluar y erradicar Achatina fulica (Gastropoda: Achatineaceae) en Ecuador. Boletim Técnico IASA, Serie Zoológica, 2: 45-52.
Fontanilla, I. K., Hudelot, C., Naggs, F. & Wade, C.M. (2007). Achatina fulica: its molecular phylogeny and genetic variation in global populations. http://www.malacsoc.org.uk/The_Malacologist/BULL48/forum48.htm. Re-published: Abstracts World Congress of Malacology, Antwerp, 15-20 July 2007: 63.
Martinez, R. & Martinez, E. (1997). Nota acerca de la Achatina (Lissachatina) fulica (Bowdich, 1822). Peligroso caracol africano (Pulmonata-Achatinidae) introducido en Venezuela. Acta Biologica Venezuelica, 17: 37-40.
Achatina in Ecuador
02-07-2008 09:08
Recently I wrote about an observation of some
pet
snails
near Mindo, which turn out to be Achatina fulica
(Bowdich, 1822). This is the first record for this
species in Ecuador. Very unfortunately, I should add,
as this pet species is a dangerous pest!
It looks very much that economic profit (or better: stupid shortsightedness) has lured somebody to set up a snail farm in Ecuador. My guess is that they know very well what they are doing, since on the CORPEI site they call it concealed "Chinese Escargot". But we know better than that...
A recent paper has described the rapid spread of this species in Brazil. Let's just hope that it will be possible to eradicate it in Ecuador, before it becomes a major threat to agriculture, health and biodiversity. Just today I got confirmation from an independent source that Achatina has been found this year in a ship which came from Guayaquil.
Update: Thanks to Carl Christensen, who found the following text in a newsletter of a tourist information organisation, we now know that already in 2005 Achatina must have been established in the country:
False promises and African snails
The offer to receive a spotlessly clean skin thanks to snail slime could destroy the ecosystem of a whole country. On the basis of publications about the thaumaturgy of the cream made of the secretion, there has been a development of a parallel market along the streets of the coast that does not apply to any regulations.
The main problem is that for the fabrication of the salve animals of the breed Giant African Snail (Achatina fulica) are used. The name of the giant derives from its size that can extend in its natural tropical surroundings in West Africa more than 11.8 inches. The mollusks which can be bought for one dollar a piece are sold in Esmeraldas for example as domestic species [emphasis added]. The situation is been aggravated by the fact that the Giant African Snail looks very similar to the Ecuadorian Amazonian breed (Strophocheilus popelairianius) which is close to extinction!
The ministry of the environment is concerned: the gluttony of the intruder, its high reproduction rate and its existence as carrier of a disease makes it to a special blatant danger. The snails nourish on agricultural products and thus form a risk for banana plantations, vegetable fields and fruit trees. The immediate extermination of the pest is indispensable! In some countries such as the USA, Australia, Canada, China and Israel the breed and import of the snails is illegal – whereas its flesh is much liked by the Italians and Spaniards.
It looks very much that economic profit (or better: stupid shortsightedness) has lured somebody to set up a snail farm in Ecuador. My guess is that they know very well what they are doing, since on the CORPEI site they call it concealed "Chinese Escargot". But we know better than that...
A recent paper has described the rapid spread of this species in Brazil. Let's just hope that it will be possible to eradicate it in Ecuador, before it becomes a major threat to agriculture, health and biodiversity. Just today I got confirmation from an independent source that Achatina has been found this year in a ship which came from Guayaquil.
Update: Thanks to Carl Christensen, who found the following text in a newsletter of a tourist information organisation, we now know that already in 2005 Achatina must have been established in the country:
False promises and African snails
The offer to receive a spotlessly clean skin thanks to snail slime could destroy the ecosystem of a whole country. On the basis of publications about the thaumaturgy of the cream made of the secretion, there has been a development of a parallel market along the streets of the coast that does not apply to any regulations.
The main problem is that for the fabrication of the salve animals of the breed Giant African Snail (Achatina fulica) are used. The name of the giant derives from its size that can extend in its natural tropical surroundings in West Africa more than 11.8 inches. The mollusks which can be bought for one dollar a piece are sold in Esmeraldas for example as domestic species [emphasis added]. The situation is been aggravated by the fact that the Giant African Snail looks very similar to the Ecuadorian Amazonian breed (Strophocheilus popelairianius) which is close to extinction!
The ministry of the environment is concerned: the gluttony of the intruder, its high reproduction rate and its existence as carrier of a disease makes it to a special blatant danger. The snails nourish on agricultural products and thus form a risk for banana plantations, vegetable fields and fruit trees. The immediate extermination of the pest is indispensable! In some countries such as the USA, Australia, Canada, China and Israel the breed and import of the snails is illegal – whereas its flesh is much liked by the Italians and Spaniards.