Tag Archives: megalobulimus

New issue of Tentacle

Robert Cowie and his co-editors have succeeded to publish a new issue of Tentacle, the IUCN/ SSC Newsletter that appears annually. There are several papers in this issue relevant to Neotropical malacology.

Salvador & Simone report on a presumably new Leiostracus species from Minas Gerais, which may be extinct as the small patch of rainforest where it was found a few years ago has been cleared meanwhile. The variation in colour pattern observed in their material is, despite their remark of being “extremely variable”, not uncommon in arboreal species like Leiostracus, Drymaeus and other genera in the superfamily.

Schermafbeelding 2015-02-18 om 12.11.52

Agudo-Padrón & Luz report on a nursery project for Megalobulimus paranaguensis (Pilsbry & Ihering, 1900) in the city of Joinville (Santa Catarina). The first author, in a separate note, also on a salvage effort for a small population of Drymaeus (Mesembrinus) interpunctus (Martens, 1887). In a third note, he draws attention to the precarious official conservation status for mollusks in the States of Santa Catarina and Rio Grande do Sul, Brazil.

Suarez & Martínez report on the finding of a new population of Cerion tridentatum rocai Clench & Aguayo, 1953, on the Itabo River bank, in Boca Ciega, Havana, Cuba, approximately 4 km west of the type locality.

Schermafbeelding 2015-02-18 om 12.19.52

Fernández et al. provide data on rock dwelling species at risk due to recreational developments in Holguín, Cuba. Given the recent political changes this risk may turn out to devastate other snail populations along the Cuban coast in the time to come.

Simone draws attention to the recently described Adelopoma species from a park in Sao Paulo (see also here).

In three separate notes, Herrera reports on snails from the Island of Youth, Cuba (= Isla de la Juventus, formerly Isla de Pinas). One with a new locality record for a colour variation of Liguus fasciatus, one with a new locality for Priotrochatella stellata, and the last one on conservation issues in the Sierra de las Casas.

Schermafbeelding 2015-02-18 om 13.12.23

Santos and a suite of co-authors finally devote two pages on their efforts to update the list of endangered non-marine molluscs in Brazil. The new list features eight land snail species.

Comparing these papers with previous issues, it may be noted that the diversity of authors and topics (Brazilian and Cuban land snails) is diminishing. The complete issue is available online at: http://www.hawaii.edu/cowielab/Tentacle/Tentacle_23.pdf

References:
AGUDO-PADRÓN, A.I., 2015a. Small actions making big differences: rescue of small native arboreal snails in an urban area of Florianópolis, Santa Catarina State, Central Southern Brasil. – Tentacle 23: 11-12.
AGUDO-PADRÓN, A.I., 2015b. The precarious official conservation status of molluscs in the States of Santa Catarina and Rio Grande do Sul, Southern Brasil. – Tentacle 23: 19-20.
AGUDO-PADRÓN, A.I. & LUZ, J.S. da., 2015. Active conservation of threatened indigenous land gastropods in the urban area of Joinville, Santa Catarina State, Central Southern Brasil. – Tentacle 23: 9-10.
FERNANDEZ, A., SUAREZ, A. & FRANKE, S., 2015. New records of rock dwelling mooluscs at risk from tourist developments on the coastal zone of Pesquepo Nuevo, Holguin, Cuba – Tentacle 23:  13-15.
HERRERA, J., 2015a. New localities for Liguus fasciatus (Müller, 1774) from the Island of Youth, Cuba. – Tentacle 23: 15-16.
HERRERA, J., 2015b. New locality for Priotrochatella stellata (Gastropoda: Helicinidae) from the Island of Youth, Cuba. – Tentacle 23: 20-21.
HERRERA, J., 2015c. Land snails of Suerra de las Casas protected area (Island of Youth, Cuba) and their conservation problems. – Tentacle 23: 23-24.
SALVADOR, R.B. & SIMONE, L.R.L., 2015. The discovery and possible extinction of a Leiostracus land snail in Southeastern Brasil. – Tentacle 23: 7-9.
SANTOS, S.B. dos et al., 2015. Observations on the review of the list of endangered non-marine molluscs of Brasil. – Tentacle 23: 26-28.
SIMONE, L.R.L., 2015. A new species discovered in an urban park within the third largest city in the world. – Tentacle 23: 18-19.
SUAREZ, A. & MARTINEZ, J., 2015. New data on Cerion tridentatum rocai, locally endemic to Boca Ciega, La Habana, Cuba. – Tentacle 23: 10-11.

Population structure Megalobulimus

Miranda et al. (2015) published (advanced online) a paper dealing with two Megalobulimus species. Their abstract reads as follows: “Native Megalobulimus paranaguensis was identified on Brazil’s Ilha Porchat promontory, an area that Achatina fulica commonly populates. The population structures of these species were investigated for interactions. Spatial distribution, niche overlap and mark–recapture analysis were conducted. The outer lip of M. paranaguensis and environmental variables were measured.

Miranda f3

Miranda f2

One and two abundance peaks were observed for A. fulica and M. paranaguensis, respectively. Survivorship was higher in A. fulica. Distribution was aggregate for M. paranaguensis, whereas for A. fulica it varied from random to aggregate. Both species aggregate as abundance increases. The lifespan of M. paranaguensis in this location is shorter than its lifespan in a nearby location. Achatina fulica was affected by soil temperature and humidity; M. paranaguensis was influenced by humidity. Niche overlap was random. The results show that M. paranaguensis can keep its
natural activity and abundance in the presence of A. fulica, but environmental degradation impacts M. paranaguensis and should be evaluated.”

As can be seen from the above figures, the observations were made during one year resp. 7 months. The conclusions thus have to be viewed within the context of this limited evidence.

References:
Miranda, M.S., Fontenelle, J.H. & Pecora, I.L. (2014 [2015]). Population structure of a native and an alien species of snail in an urban area of the Atlantic Rainforest. – Journal of Natural History, 49: 19-35.

Copulation in Megalobulimus

Marinus Hoogmoed, a former colleague in Leiden and calling himself proudly “an old, traditional herpetologist” (i.e. still studying morphology), kindly sent me these photographs of two snails in copulation. He found them in disturbed rainforest in the Serra Sul de Carajas (700 km S Belém).

Slakken parend Flona Carajas pitfall 8 DSC02262Slakken parend Flona Carajas pitfall 8 DSC02264

While I have rarely seen photographs from snails copulating under field conditions, these pictures are (perhaps?) a rare find. They are from a red-lipped Megalobulimus species, but since several are reported from that part of Brazil, it may be difficult to pinpoint a species name to them.

Many thanks Marinus, and proudly continue with your good work!

Colombian Megalobulimus

Jaramillo et al. (2014) recently published a paper which combined anatomical and molecular research on Megalobulimus oblongus (Müller, 1774) (Strophocheilidae) from Colombia.

The abstract reads: “In this work was done morphological and molecular analysis to 28 land snails of Megalobulimus oblongus, collected in different departments of Colombia, deposited in a reference collection. For morphological characterization, the animals were dissected in a stereomicroscope. The reproductive system and the shell were described. Measures were taken to structures of the reproductive system. Of the shell were described its shape, color, number of whorls and ornamentation and equally basic measures were taken using a digital caliper. For molecular analysis were used two mitochondrial markers, 16S rRNA and cytochrome C oxidase subunit I (COI). Only one haplotype was obtained for each marker, even for individuals of different and distant biogeographical regions. This study suggests that M. oblongus is in danger, therefore are urgent investigations about reproduction, population genetics and biogeography to clarify its situation in Colombia. It also demonstrates that the reference collections and tissue banks are sources of valuable information since they allow knowing aspects related with the species’ risk that serve as an input for the design of conservation actions”.

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The Colombian specimens were collected at six different sites, three of which are in Dept. Antioquia, and one in adjacent Caldas; two originated from the eastern departments. The genetic invariability found was linked to human transportation due to illegal trade. The conclusion that this species, widespread in South America, in endangered in Colombia seems premature. Not all species need to be conserved everywhere anytime in any political-administrative region; this might be a misconception of what biodiversity really is.

The data in Table 2 can be supplemented with the locality of Megalobulimus parafragilior Leme & Indrusiak, 1990: Brazil, São Paulo, Peruibe (MZSP 86740), as mentioned in the source from which the sequence was derived.

Reference:
Jaramillo Roldán, E., López Martínez, J., Ramírez, R. & Velásquez Trujillo, L. , 2014. Análisis morfológico del sistema reproductor e identificación molecular a través de los marcadores mitocondriales COI y 16S rRNA de Megalobulimus oblongus (Mollusca, Strophocheilidae) de Colombia. – Revista peruana de Biología 21: 79–88. http://bit.ly/1rGTAFs

New Megalobulimus from Peru

Another end-of-the-year paper is on Peruvian Megalobulimus species by Borda & Ramírez. The abstract reads:

Megalobulimus K. Miller, 1878 is a genus of land snails that includes the largest living snails in the Neotropics. The main goal of this paper was to review all species of Megalobulimus that have a red lip, and which are distributed in Peru. We carried out a detailed description of their shells and soft parts, and conducted a multivariate analysis on their shells and geographic distribution. There are two species reported from Peru, Megalobulimus capillaceus (Pfeiffer, 1855) and Megalobulimus separabilis (Fulton, 1903). Megalobulimus capillaceus is known to occur in three regions – San Martín, Huánuco and Cusco – but the Cusco population is undoubtedly different from all remaining populations, and is recognized herein as a new species, Megalobulimus florezi sp. nov. This species has a more elongated shell, penis clubshaped, epiphallus longer, and free oviduct longer than M. capillaceus. By contrast, the male genitalia of M. separabilis is filiform and does not present an external diverticulum in the free oviduct.

Borda & Ramirez 2013

Reference:

Borda, V. & Ramirez, R. (2013). Re-characterization of the red-lip Megalobulimus (Gastropoda: Strophocheilidae) from Peru with description of a new species. Zoologia 30: 675–691.

Biodiversity and endemism in Megalobulimus and Systrophia

Peruvian land snails are relatively well known, but nevertheless there remains a lot studies to be done to further our knowledge. One study dealing with two different genera appeared some time ago (Ramírez et al. 2012), dealing with the genera Megalobulimus (here considered as part of the Strophocheilidae, but often as Megalobulimidae) and Systrophia (Scolodontidae).

In this work we performed a biogeographic study of two genera of Amazonian land snails, Megalobulimus (Strophocheilidae) and Systrophia (Scolodontidae). We used samples from different regions of the Peruvian Amazon, as well as bibliographic information. We analyzed both nuclear (5.8S-ITS2-28S rRNA) and mitochondrial (16S rRNA) genes to re construct phylogenies and obtain hypotheses concerning the evolutionary relationships among Amazonian genera and other species with global distribution. The nuclear phylogeny allowed us to determine the evolutionary position of both genera, and the mitochondrial phylogeny permitted the differentiation of species at the intrageneric level. We found that Megalobulimus clustered with the non-achatinoid clade within Stylommatophora, as expected, but its relationship to family Acavidae could not be demonstrated. Systrophia did not cluster with any of the two established clades, but formed a basal one within Stylommatophora. The mitochondrial gene 16S rRNA allowed us to differentiate Megalobulimus species, and performed well for DNA barcoding of these edible snails. Biogeographical analysis revealed several endemic species in the Peruvian Amazon within both genera, highlighting the Chanchamayo and Inambari biogeographic units.

Reference:
Ramirez, R., Borda, V., Romero, P., Ramirez, J., Congrains, C., Chirinos, J., Ramirez, P., Elena Velasquez, L. & Mejia, K. (2012). Biodiversidad y endemismo de los caracoles terrestres Megalobulimus y Systrophia en la Amazonia occidental [Biodiversity and endemism of the western Amazonia land snails Megalobulimus and Systrophia]. — Revista Peruana de Biologia 19 (1): 59–74. Available at http://bit.ly/Hq94cR