Tag Archives: bulimulus

Bulimulus as host for nematods

Today I was alerted of a citation of my paper on Bulimulus phylogeny, and when I looked up the citation I found a paper by Martins et al. which will appear in the Journal of Invertebrate Pathology.

“The terrestrial gastropod Bulimulus tenuissimus is widespread in South America. It is an intermediate host of many parasites, but there are no records of infection of this snail by Angiostrongylus cantonensis, despite the occurrence of this parasite and angiostrongyliasis cases in the same areas in which B. tenuissimus occurs. For this reason, it is important investigate the susceptibility of B. tenuissimus to A. cantonensis-infection, since it can be used as intermediate host of A. cantonensis, increasing the list of terrestrial gastropods that infect wild and domestic animals and humans with this parasite. The purpose of this study was to evaluate the susceptibility of B. tenuissimus to experimental infection with L1 larvae of A. cantonensis. The snails were exposed to 1,200 L1 larvae and it was possible observe many developing larvae in the cephalopedal mass and mantle tissues, with intense hemocyte infiltration and collagen deposition, but no typical granuloma structures were formed. The glucose content and lactate dehydrogenase activity in the hemolymph varied, indicating an increase of anaerobic energy metabolism in the middle of infection, but with a tendency to return to normal values at the end of pre-patent period. This was corroborated by the marked reduction in the glycogen content in the cephalopedal mass and digestive gland in the first and second week after exposure, followed by a slight increase in the third week. The content of pyruvic acid in the hemolymph was 14.84% lower at the end of pre-patent period, and oxalic acid content was 41.14% higher. These results indicate an aerobic to anaerobic transition process. The PAS reaction showed a large amount of glycogen inside the developing larvae and muscular tissues of the cephalopedal mass, indicating that despite the high consumption of this polysaccharide by the parasite, the snail is able to maintain its energy metabolism based on carbohydrates. The results reveal that B. tenuissimus is a robust host, which can live with the developing larvae of A. cantonensisand overcome the metabolic damages resulting from parasitism.”

No phylogenetic related work thus, it seems that the citation was only used to support the wide-spread occurrence of Bulimulus species in different areas and the fact that some of these are easily imported and may act as alien species. I also found a (unjustified) citation in Martins et al. of a paper by Parent & Crispi dealing with the radiation of Galápagos Naesiotus species, which were misidentified as Bulimulus.

Although this seems a case of serendipity, it is interesting to know that Bulimulus tenuissimus is a potential host for Angiostrongylus cantonensis, given the fact that this is a potential health threat for humans. An update will be given once this paper is formally published.

Martins, F.G. et al., 2018. Bulimulus tenuissimus (Mollusca) as a new potential host of Angiostrogylus cantonensis (Nematoda), a histological and metabolic study. – Journal of Invertebrate Pathology



Bulimulids introduced in the Pacific

Carl Christensen kindly sent me two papers which testify that two members of the Bulimulidae have been introduced to Pacific Islands.

The first one is an inventory of introductions in the Hawaiian Islands (Hayes et al., 2012). Bulimulus guadalupensis is reported from one of the islands.


“This species originated in the Caribbean, where it is widespread, especially in disturbed habitats. It has been introduced to Florida, probably in association with agricultural or horticultural plants, and has been recorded in abundance in lawns and among ornamental plants in a residential area, as was the present material. It is likely that it was introduced via the horticultural trade. The only two localities at which the species has been found in the Hawaiian islands were close together and were also the only two localities at which Vallonia pulchella was found”.

In the second paper the occurrence of Drymaeus multilineatus (Say, 1825) is recorded on the island of Guam. According to Christensen, this species was introduced on that island before 1978, “likely inadvertently with cultivated plants” (Kerr & Bauman, 2013).

Hayes, K.H., Yeung, N.W., Kim, J.R. & Cowie, R.H., 2012. New records of alien Gastropoda in the Hawaiian Islands: 1996-2010. – Bishop Museum Occasional Papers, 112: 21-28.
Kerr, A.M. & Bauman, S., 2013. Annotated checklist of the land snails of Mariana Islands, Micronesia. – University of Guam Marine Laboratory Technical Report, 148: i-vii, 1-72.

Bulimulus as world travelers

Some Bulimulus species can act as alien species, as has been reported here extensively with introductions in Florida (B. guadalupensis, B. aff. sporadicus), Costa Rica and Ecuador (both B. guadalupensis). As recent research has shown (Breure 2016 PeerJ in press), DNA can help to reveal the likely source of origin. However, this is only possible if there is sufficient reference data available, i.e. sequences from specimens adequately identified with good locality data.


Recently, a Bulimulus species was detected on containers originating from India, Thailand, southern China and Singapore in the port of Darwin, north Australia. Initially confused with a Cerastid species, several people now agree that it is likely a Bulimulid. However, which species? There is now speculation it is a species from Brazil or Argentina, which would place it in the Bulimulus sporadicus species-complex, extending from northern Argentina (B. bonariensis), Paraguay, Bolivia into southern Brazil. This species complex is insufficiently known, its morphological variation within its distribution is ill-documented, and with only one sequence from Paraguay as reference material the hope for a quick fix of this hitch-hiking snail is in vain. So before we might be able to solve this issue, the first action is to collect living specimens throughout the distribution range and sequence them. Work for local malacologists or a student in need for an interesting and an useful topic! Any takers?

Luckily, Bulimulus species can only be a nuisance, so far I have never heard of any real damage to the local fauna and flora.

Digital field work: the next step?

Bill Frank has already been doing some very clever detective work in and around Jacksonville, Florida on the occurrence of Bulimulus aff. sporadicus (e.g., here and here). Today his next message read: “Was using Google Street View this afternoon on my computer to “drive” or maybe I should say “mouse” around Jacksonville looking for Bulimulus sporadicus. Much to my surprise I found a location where it appeared that Bulimulus were present but the Google imagery wasn’t high enough in resolution to be absolutely sure plus the imagery was dated April, 2013.


Although in the past I have used Street View to view snails after I had first visited the location and confirmed their presence, today’s find, if confirmed by an on site visit, would be the first time that snails would were found solely based upon street view. So I jumped in the car and drove downtown to the location in question which is on Deer Street underneath the US-1 overpass. Upon arrival I found Bulimulus in the exact location as depicted in Street View on the concrete wall in somewhat modest numbers. However on the other side of the road live specimens were present in large numbers on another concrete wall. After looking around for a bit I changed my estimation from hundreds to probably tens of thousands of snails being present. The ground was just white with empty shells and represents the most specimens I have ever seen at a single location which is really saying something. This location within the past couple of  years has undergone a complete transformation due to road/overpass construction which makes the find all that more impressive (i.e. the snails had accomplished this in a relatively short period of time)”.

Detailed photos of the locality can be found in this document: Deer Street

So one might ask, will malacological field work turn into a digital exercise? Perhaps the saying of football coach Johan Cruijff may be apt in this context… “Je ziet het pas als je het doorhebt” [you see it when you get it]. Bill’s previous experience undoubtedly helped him a lot, but still: Chapeau for this digitally savvy malacological detective!

Santa Catarina snails

Just published by Ignacio Agudo, the ‘regional malacologist’ of Brazil’s Santa Catarina, is an updated overview of its malacofauna (Agudo, 2014). This new (bilingual Spanish/Portuguese) paper appeared in the recently started journal Bioma, which is edited in El Salvador, Central America.

The paper is, according to the English abstract, “[p]roduct of 18 years of field researches, examination of specimens deposited in museum collections and parallel referencial studies, the systematic continental malacological inventory of Santa Catarina’s State/SC, subtropical central southern Brazil region, is finally presented, behaving a total of 220 species and subspecies of land and freshwater mollusc forms (190 gastropods – 148 terrestrial, 2 amphibian, 40 freshwater – and 30 limnic bivalves), included in 97 genera and 37 families. Informations concerning known regional biogeographic distribution are included.”

The taxonomic classification used is not always up to date, and some groups, e.g. Simpulopsis, ended up in the wrong family (Amphibulimidae; should be Simpulopsidae Schileyko, 1999).

Screen Shot 2014-07-05 at 08.26.16

Some of the photographs are good and some have been maltreated during the editorial process resulting in awkward colours. An interesting picture is illustrating the species identified as Bulimulus sporadicus (d’Orbigny, 1835). This taxon, which has been synonymised by some authors with Bulimulus bonariensis (Rafinesque, 1833), has now a huge distribution. Ranging from eastern Bolivia, northern Argentina, Uruguay, Paraguay and southern Brazil, the new record from Santa Catarina adds considerable more square kms. The problem with Bulimulus species is that they all look more or less the same: brownish-corneous. Comparing this picture with the type specimen of d’Orbigny, there are obvious differences in shape and coloration. It may well be possible that within this large distribution range cryptic speciation is at play. Only a detailed study of adequately sampled lots, including molecular research, can solve this question.

afbeelding 1 09 12 184

AGUDO-PADRÓN, A.I., 2014. Inventario sistemático de los moluscos continentales ocurrentes en el Estado de Santa Catarina, Brasil / Inventário sistemático dos moluscos continentais ocorrentes no Estado de Santa Catarina, Brasil. – Bioma, 2(21): 6–23. Available at https://edicionbioma.wordpress.com/2014/07/03/revista-bioma-julio-2014/ — Click on  “Descarga BIOMA Julio 2014” to download the whole issue.

An elegant U-loop?

Invasive species are a well-documented when they are discovered in countries with good monitoring systems. However, in some instances these ‘hidden secrets’ of economic liberalisation and globalisation stay under the radar of authorities and scientists.

David Robinson kindly sent an example of this when showing me these pictures.


This is a Bulimulus species, possibly B. sporadicus (d’Orbigny, 1835); the specimen is not fully grown.

At first I couldn’t believe my eyes when I read where it originated from. Guinea? Perhaps an error for Guiana? No, it’s the West African country!! A Bulimulus species in Africa?!?

These specimens (not the first instance!) were intercepted when they were brought into a U.S.A. port. David said it is likely that they first were exported from the Houston area with oil-drilling equipment. “Most of the oil-drilling equipment goes to West African countries from Houston where the containers get contaminated. The port areas must be crawling with invasive snails there. Then when the containers come back to different ports in the US, they are crawling with Texan snails.”

This implies that in several countries lots of American and European species must be present (we know the reports, don’t we?), but this is the first time I hear that an alien species in one country becomes an exotic in a second one and then gets re-imported in the first country at different places. My ‘U-loop’ hypothesis, perhaps logical that it should happen one day, is here reported for the first bulimulid species criss-crossing the ocean.

New species list Santa Catarina

Santa Catarina state in southern Brazil is becoming one of the best-known regions within Brazil, thanks to the efforts of Ignacio Agudo-Padrón. A new paper lists 12 additional continental species from the state (Agudo-Padrón et al., 2014).

Among the new records are the following terrestrial species: Helicina cf. laterculus F. Baker, 1914; Adelopoma brasiliensis Morretes, 1954; Bulimulus cf. sporadicus (d’Orbigny, 1835); Pseudoxychona polytricha (Ihering, 1912); Simpulopsis gomesae Silva & Thomé, 2006; Simpulopsis promatensis Silva & Thomé, 2006; Gastrocopta solitaria (E.A. Smith, 1890); Pupisoma discoricola (Adams, 1845); Leptinaria cf. ritchiei Pilsbry, 1907; Tamayoa cf. banghaasi (Boettger in Thiele, 1927).


Agudo-Padrón, A.I., Luz, J.S. da, Lisboa, L.K. & Zermiani, A.E. (2014). Additional twelve new records to inventory of continental
mollusc species from Santa Catarina State/ SC, Central Southern Brazil. — Boletin de la Asociación Argentina de Malacologia 3(2): 11–20.
The journal issue is available at: http://bit.ly/NTbeEy. Other issues are available on http://www.malacoargentina.com.ar/boletin.html