USA
Bulimulus again
05-07-2010 21:58
This weekend Bill Frank
went to visit the new
locality NW Jacksonville, where Harry Lee
collected the “mysterious Bulimulus”.
Quoting from his report:
“Knowing that I was in the right place wasn't real helpful as I was initially unable to find any Bulimulus. Finally, I found one empty shell and spread out a search pattern from there. Finally I discovered the secret. There is one type of weed that grows in the roadside swale between the road and the ditch and it was under these patches of weeds that the Bulimulus were hiding. I found them nowhere else. It was kind of interesting as a small plant would have one live Bulimulus and a large plant would have 4-5. To say that the species is common is an understatement. I collected plenty (both live and empty shells) and could have collected a whole lot more if I had wanted them. All of those were from the swale which was mowed very close and recently. I can imagine that the nearby high growth weedy area is probably full of them. The only other mollusks I saw in this area were a very modest number of Polygyra cereolus.”
The locality is pictured to the north, and Bulimulus is on the left under the weeds.
When you look closely to the snails that Bill found, you will notice that some have the striped pattern, but others not. The latter thus resemble those from Duval County.
Thanks Bill for sharing the information.
Quoting from his report:
“Knowing that I was in the right place wasn't real helpful as I was initially unable to find any Bulimulus. Finally, I found one empty shell and spread out a search pattern from there. Finally I discovered the secret. There is one type of weed that grows in the roadside swale between the road and the ditch and it was under these patches of weeds that the Bulimulus were hiding. I found them nowhere else. It was kind of interesting as a small plant would have one live Bulimulus and a large plant would have 4-5. To say that the species is common is an understatement. I collected plenty (both live and empty shells) and could have collected a whole lot more if I had wanted them. All of those were from the swale which was mowed very close and recently. I can imagine that the nearby high growth weedy area is probably full of them. The only other mollusks I saw in this area were a very modest number of Polygyra cereolus.”
The locality is pictured to the north, and Bulimulus is on the left under the weeds.
When you look closely to the snails that Bill found, you will notice that some have the striped pattern, but others not. The latter thus resemble those from Duval County.
Thanks Bill for sharing the information.
On intra-specific variation
02-07-2010 17:52
Bill Frank sent me some
additional pictures of specimens of
Bulimulus
collected recently near
Jacksonville in Nassau County. He noted difference
with specimens collected inside the city (Duval
County), especially in the striping of the animals.
Specimens from Duval County above, Nassau County below.
Just today I read the comprehensive and thorough paper of Herbert & Moussalli (2010). They have a section on Comparative morphological observations, in which they noted that “due to intra-specific variability, head-foot colour seems to be of limited value for species discremination [...]. In most cases, data on body coloration is available for too few specimens to make meaningful assessments”.
Although in this case the difference is caused by a pattern in the mantle tissue, my hypothesis is that this is merely due to intra-specific variation. To be tested when molecular data become available for both populations.
Reference:
Herbert, D.G. & Moussalli, A., 2010. Revision of the larger cannibal snails (Natalina s.l.) of southern Africa -- Natalina s.s., Afrorhytida and Capitina (Mollusca: Gastropoda: Rhytididae). African Invertebrates 51: 1-132.
Specimens from Duval County above, Nassau County below.
Just today I read the comprehensive and thorough paper of Herbert & Moussalli (2010). They have a section on Comparative morphological observations, in which they noted that “due to intra-specific variability, head-foot colour seems to be of limited value for species discremination [...]. In most cases, data on body coloration is available for too few specimens to make meaningful assessments”.
Although in this case the difference is caused by a pattern in the mantle tissue, my hypothesis is that this is merely due to intra-specific variation. To be tested when molecular data become available for both populations.
Reference:
Herbert, D.G. & Moussalli, A., 2010. Revision of the larger cannibal snails (Natalina s.l.) of southern Africa -- Natalina s.s., Afrorhytida and Capitina (Mollusca: Gastropoda: Rhytididae). African Invertebrates 51: 1-132.
Florida Bulimulus again
29-06-2010 19:01
A few days ago,
the mysterious
Bulimulus
species
from Jacksonville
was found northeast of the city. The localities
are 27.8 kms apart, as the crow flies. As I doubt
if any crow (or whatever Floridan bird) may have
carried the eggs of this species, it remains
mysterious how this population got there. Was is
transported by trucks visiting the Duval Container
Co. station? Has it been there for more years,
unnoticed to local snail hunters?
Questions abound, answers yet to come.
Bulimulus sp. aff. guadalupensis (Bruguière, 1789)
cf. West Indian Bulimulus
[same taxon as Duval Container Co. station]
USA: Florida: Nassau Co.
US 301, 0.1 mi N Seaboard Coast Line RR.
Just W roadside, grassy shoulder, Fifteensnails actively crawling on larger weeds.
30º30.622'N 081º52.596'W.
H.G. Lee and E.W. Cavin! 26 June, 2010.
Thanks to Harry Lee for collecting and to Bill Frank for reporting.
Questions abound, answers yet to come.
Bulimulus sp. aff. guadalupensis (Bruguière, 1789)
cf. West Indian Bulimulus
[same taxon as Duval Container Co. station]
USA: Florida: Nassau Co.
US 301, 0.1 mi N Seaboard Coast Line RR.
Just W roadside, grassy shoulder, Fifteensnails actively crawling on larger weeds.
30º30.622'N 081º52.596'W.
H.G. Lee and E.W. Cavin! 26 June, 2010.
Thanks to Harry Lee for collecting and to Bill Frank for reporting.
...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.
Florida Liguus populations
03-12-2009 21:10
Tree snails in the
Florida Keys have been studied for about a century
now. They are a good subject to follow the fate of
the different populations on different ‘hammocks’.
Exactly what Fadely (2009) has done.
The study examined the past and present spatial distribution of the Florida tree snail, L. fasciatus solidus, in the Long Pine Key area of the Everglades National Park. Remote sensing and mobile GIS were used to create a GIS database of the field research results. Collection and survey-based data were used to create a current spatial distribution map of L. fasciatus solidus throughout the Long Pine Key area. The data collected during the 2006 survey were compared to a 1931 survey of the same study area conducted by Dr. William Clench of the Museum of Comparative Zoology (MCZ) of Harvard University. The data was used to determine the success of L. fasciatus solidus from 1931 to 2006, to evaluate a correlation between hammock size and the number of color forms, and to detect migration patterns of L. fasciatus solidus within the Long Pine Key area of Everglades National Park. Based on the average success rate for the seven color forms and the hammocks, the L. fasciatus solidus population in the Long Pine Key area
exemplifies one of a stable community. Each color form used for the analysis had a success rate between 67% and 100%. These percentages can only be the worst case scenario based on the fact that many Liguus were not observed, and any others that would have been observed, would only increase the success rate.
An interesting hypothesis is about the relation between the number of colour forms and the size of the hammock. The author supposed that there would be a linear relationship. However, as the figures show, this is clearly not the case. It is not evident from the data presented in his report to what extent re-introductions, migration and differences in data collection between the 1931 and 2006 surveys affect these results.
Reference:
Fadely, J.R., 2009. Population distribution of Liguus fasciatus solidus in Long Pine Key of Everglades National Park: i-xvi, 1-62. Thesis (M.Sc.), Florida Atlantic University, Boca Raton, Florida.
The study examined the past and present spatial distribution of the Florida tree snail, L. fasciatus solidus, in the Long Pine Key area of the Everglades National Park. Remote sensing and mobile GIS were used to create a GIS database of the field research results. Collection and survey-based data were used to create a current spatial distribution map of L. fasciatus solidus throughout the Long Pine Key area. The data collected during the 2006 survey were compared to a 1931 survey of the same study area conducted by Dr. William Clench of the Museum of Comparative Zoology (MCZ) of Harvard University. The data was used to determine the success of L. fasciatus solidus from 1931 to 2006, to evaluate a correlation between hammock size and the number of color forms, and to detect migration patterns of L. fasciatus solidus within the Long Pine Key area of Everglades National Park. Based on the average success rate for the seven color forms and the hammocks, the L. fasciatus solidus population in the Long Pine Key area
exemplifies one of a stable community. Each color form used for the analysis had a success rate between 67% and 100%. These percentages can only be the worst case scenario based on the fact that many Liguus were not observed, and any others that would have been observed, would only increase the success rate.
An interesting hypothesis is about the relation between the number of colour forms and the size of the hammock. The author supposed that there would be a linear relationship. However, as the figures show, this is clearly not the case. It is not evident from the data presented in his report to what extent re-introductions, migration and differences in data collection between the 1931 and 2006 surveys affect these results.
Reference:
Fadely, J.R., 2009. Population distribution of Liguus fasciatus solidus in Long Pine Key of Everglades National Park: i-xvi, 1-62. Thesis (M.Sc.), Florida Atlantic University, Boca Raton, Florida.
Photo of the day (76): Drymaeus
09-11-2009 18:46
Photo of the day (63): Huttonella
23-09-2009 07:32
Bill Frank sent in some excellent pictures that he
took of
Huttonella
bicolor
(Hutton, 1834). He found these specimens when
re-visiting the site where he had collected the
(hitherto)
mysterious
Bulimulus
species.
Since this is a tiny species, he considered himself lucky to see it amongst the debris. “If it wasn’t red, I would never have noticed it”, Bill said.
H. bicolor was already known from Florida, but it is hitherto unknown how far north the species already has spread up the East Coast of the USA.
Since this is a tiny species, he considered himself lucky to see it amongst the debris. “If it wasn’t red, I would never have noticed it”, Bill said.
H. bicolor was already known from Florida, but it is hitherto unknown how far north the species already has spread up the East Coast of the USA.
A Gringo ghost Bulimulus
17-08-2009 20:04
After my
recent
post
on
Bulimulus
species in the USA, I received a link to the
site
of Bill Frank and Harry Lee. They have two pages
on
Bulimulus
guadalupensis
in Florida.
The pictures shown on these pages are actually *not* B. guadalupensis, but a still unknown species.
Harry found the small population at a trash pile in February 2009. As Bill wrote to me, “Thus far the snails have only been found in a very small area (about 3 x 5 meters) in an industrial area in the old core city of Jacksonville next to a major rail line and a factory often visited by trucks. I would assume that is how the snails got to the location where Dr. Lee Initially discovered them. I have repeated worked that area thoroughly since they were initially found in February. A total of 12 living specimens, and one empty shell, were cumulatively found over the six month period. During my last few trips no additional specimens could be found so I may have extirpated the colony. All of the specimens found were very similar in size. I kept the living snails in captivity for several months but nobody showed an interested in having them or preserved specimens for study so I euthanized them and just retained the empty shells. I check the habitat on a periodic basis for additional specimens”. Well you win some and you lose some... He was kind enough to re-visit the site, but only found one very juvenile before he had to back off because of a thunderstorm. Anyway, the population still exists.
Because B. guadalupensis also has an unicoloured form, it is easy to confuse this species with the figured one. After all, these Bulimulus species are all smallish and brownish...
Since this is not an autochtonous species, it is likely imported. Until I have specimens at hand, I do not dare to give a name to these creatures (remember, they are all smallish and brownish...). Until then, it will remain a ghost species.
The true B. guadalupensis was collected in southern Florida, near Miami. The current status of this population is unknown to me.
Thanks to Bill and Harry for information on this population and to David for the link.
The pictures shown on these pages are actually *not* B. guadalupensis, but a still unknown species.
Harry found the small population at a trash pile in February 2009. As Bill wrote to me, “Thus far the snails have only been found in a very small area (about 3 x 5 meters) in an industrial area in the old core city of Jacksonville next to a major rail line and a factory often visited by trucks. I would assume that is how the snails got to the location where Dr. Lee Initially discovered them. I have repeated worked that area thoroughly since they were initially found in February. A total of 12 living specimens, and one empty shell, were cumulatively found over the six month period. During my last few trips no additional specimens could be found so I may have extirpated the colony. All of the specimens found were very similar in size. I kept the living snails in captivity for several months but nobody showed an interested in having them or preserved specimens for study so I euthanized them and just retained the empty shells. I check the habitat on a periodic basis for additional specimens”. Well you win some and you lose some... He was kind enough to re-visit the site, but only found one very juvenile before he had to back off because of a thunderstorm. Anyway, the population still exists.
Because B. guadalupensis also has an unicoloured form, it is easy to confuse this species with the figured one. After all, these Bulimulus species are all smallish and brownish...
Since this is not an autochtonous species, it is likely imported. Until I have specimens at hand, I do not dare to give a name to these creatures (remember, they are all smallish and brownish...). Until then, it will remain a ghost species.
The true B. guadalupensis was collected in southern Florida, near Miami. The current status of this population is unknown to me.
Thanks to Bill and Harry for information on this population and to David for the link.
Another Bulimulus introduced in USA
11-08-2009 08:15
David Robinson sent me last week some pictures of
a
Bulimulus
species that had been found in Texas at the site of a
stone and marble importer, with a request for further
identification.
Without knowing further details of the origin, my ID was B. sporadicus (Orbigny, 1835). This species is known from northeastern Argentina, southern Brazil, Bolivia, Paraguay and Uruguay. Typically, the species is more slender, but several more ventricose forms have been described.
Further investigation led to the conclusion that this population originates from Brazil, where it has been reported from Mato Grosso and Rio Grande do Sul.
Besides this species, several others are known to have been introduced in the USA. Bulimulus tenuissimus puellaris (Reeve, 1849) was reported by Robinson & Slapcinsky (2005) from North Carolina, Wilmington. In Florida, B. guadalupensis is spreading slowly northward and two other species have been intercepted by USDA officers.
Bulimulus is becoming more and more an alien, so far rather harmless - but you never know...
Reference:
Robinson, D.G. & Slapcinsky, J., 2005. Recent introductions of alien land snails into North America. - American Malacological Bulletin 20: 89-93.
Without knowing further details of the origin, my ID was B. sporadicus (Orbigny, 1835). This species is known from northeastern Argentina, southern Brazil, Bolivia, Paraguay and Uruguay. Typically, the species is more slender, but several more ventricose forms have been described.
Further investigation led to the conclusion that this population originates from Brazil, where it has been reported from Mato Grosso and Rio Grande do Sul.
Besides this species, several others are known to have been introduced in the USA. Bulimulus tenuissimus puellaris (Reeve, 1849) was reported by Robinson & Slapcinsky (2005) from North Carolina, Wilmington. In Florida, B. guadalupensis is spreading slowly northward and two other species have been intercepted by USDA officers.
Bulimulus is becoming more and more an alien, so far rather harmless - but you never know...
Reference:
Robinson, D.G. & Slapcinsky, J., 2005. Recent introductions of alien land snails into North America. - American Malacological Bulletin 20: 89-93.
Florida Liguus
07-08-2009 21:26
Juan C. Aguero sent me links to his work on Florida
Liguus. The first is a
gallery,
picturing many of the colour forms present at
different hammocks in Florida and on different
tree species.
But Juan also has his own blog, on which he reports his trips in the field to make the nice photographs shown in the gallery. One thing is clear: besides snails you will readily find some mosquitoes. You win some and you lose some...
Thanks Juan, and keep up the good work!
But Juan also has his own blog, on which he reports his trips in the field to make the nice photographs shown in the gallery. One thing is clear: besides snails you will readily find some mosquitoes. You win some and you lose some...
Thanks Juan, and keep up the good work!
Photo of the day
09-02-2008 17:32
Perhaps this will become a new thread, not sure
yet... After all, there are not so much new pictures
on Orthalicidae, at least not a daily basis :-)
This I found on a web site dedicated to Liguus in Florida. In human sexology it would be called interracial, in malacology intergenerical??
Liguus fasciatus (Müller, 1774) and Orthalicus floridensus Pilsbry, 1899 mating (photo: Phil Poland)
This I found on a web site dedicated to Liguus in Florida. In human sexology it would be called interracial, in malacology intergenerical??
Liguus fasciatus (Müller, 1774) and Orthalicus floridensus Pilsbry, 1899 mating (photo: Phil Poland)