Monthly Archives: March 2013

Revision of the fossil pulmonates of Itaborai Basin

In a paper just released, Salvador & Simone (2013) present a revision of the pulmonate snail fauna from the Itaboraí Basin (Paleocene) in southeastern Brazil. The fossils are known a limestone site which has been exploited till the early 1980s, after which the quarry was abandoned and a lake formed in the basin. All known fossils are now in two institutions in Rio de Janeiro.

The authors have done a nice job in re-studying all type material, complementing the diagnoses and descriptions of species which were too brief by their original authors; they also have put the fauna in the perspective of our current knowledge of the Neotropical malacofauna.

The abstract reads: The limestones of Itaboraí Basin (Middle Paleocene), Rio de Janeiro, Brazil, harbor a rich fossil molluscan fauna consisting exclusively of pulmonate snails, both terrestrial and freshwater. An extensive taxonomic revision of this paleofauna is conducted here. A new genus, Cortana, is described as well as two new species, Eoborus fusiforme and Gastrocopta itaboraiensis. The revised classification is as follows: Austrodiscus lopesi (Charopidae); Biomphalaria itaboraiensis (Planorbi- dae); “Brachypodella” britoi (Urocoptidae); Brasilennea arethusae, Brasilennea guttula, Brasilennea minor (Cerionidae); Bulimulus fazendicus, Bulimulus trindadeae, Cortana carvalhoi, Cyclodontina coelhoi, Itaborahia lamegoi, Leiostracus ferreirai, Plagiodontes aff. dentatus (Orthalicidae); Cecilioides sommeri (Ferussaciidae); Eoborus rotundus, Eoborus sanctijosephi, Eoborus fusiforme (Strophocheilidae); Gastrocopta mezzalirai, Gastrocopta itaboraiensis (Gastrocoptidae); Temesa magalhaesi (Clausiliidae). The species Strobilopsis mauryae was considered a synonym of Brasilennea arethusae; Bulimulus sommeri a synonym of Itaborahia lamegoi; andVorticifex fluminensis a synonym of Eoborus sanctijosephi. Itaboraí Basin has the most ancient records of the families Orthalicidae, Gastrocoptidae, Ferussaciidae and Strophocheilidae. Moreover, the basin’s records of Charopidae, Clausiliidae, Cerionidae, and Urocoptidae are among the most ancient in the world and, among these, those of Cerionidae, Clausiliidae and Urocoptidae deserve special attention since they are greatly removed from these families’ current distribution. Additionally, Itaboraí has the most ancient records for the genera Austrodiscus, Brachypodella, Bulimulus, Cecilioides, Cyclodontina, Eoborus, Gastrocopta, Leiostracus, Plagiodontes and Temesa. There are three endemic genera in the basin: Brasilennea, Cortana and Itaborahia. Further discussion on paleobiogeography and evolution of this paleofauna is also provided.

A new monotypic genus, Cortana, is erected for Bulimulus carvalhoi Brito, 1967 on account of the shape of the aperture and the fusiform shell. Only the holotype is known. Comparisons are being made to Eudolichotis and Otostomus, genera occurring at present more northern in Brazil.

Eoborus fusiforme n.sp. is described as a new species of Strophocheilidae, also on the basis of one shell.

Paleontology often remains a lot of guess work and may be considered as quite subjective. However, the authors provide an important contribution with a discussion on the relationships of this fauna related to the current distribution of extant taxa in the Neotropics. Unfortunately, the current situation does not give much opportunity to dig for other fossils at the Itaborai Basin, which leaves this paper as a monograph for the years to come.

Reference:
Salvador, R.B. & Simone, L.R.L., 2013. Taxonomic revision of the fossil pulmonate mollusks of Itaborai Basin (Paleocene), Brazil. Papeis Avulsos de Zoologia 53(2): 5-46. Available at http://bit.ly/YLGZS2.

Anatomy of Huttonella bicolor

Luiz Simone, very good at snail anatomy, has just published a paper on the anatomy of the streptaxid Huttonella bicolor. This is an invasive species in Brazil.

The abstract reads: The morpho-anatomy of the micro-predator Huttonella bicolor (Hutton, 1838) is investigated in detail. The species is a micro-predator snail, which is splaying in tropical and sub-tropical areas all over the world, the first report being from the Amazon Rainforest region of northern Brazil. The shell is very long, with complex peristome teeth. The radula bears sharp pointed teeth. The head lacks tentacles, bearing only ommatophores. The pallial cavity lacks well-developed vessels (except for pulmonary vessel); the anus and urinary aperture are on pneumostome. The kidney is solid, with ureter totally closed (tubular); the primary ureter is straight, resembling orthurethran fashion. The buccal mass has an elongated and massive odontophore, of which muscles are described; the odontophore cartilages are totally fused with each other. The salivary ducts start as one single duct, bifurcating only prior to insertion. The mid and hindguts are relatively simple and with smooth inner surfaces; there is practically no intestinal loop. The genital system has a zigzag-fashioned fertilization complex, narrow prostate, no bursa copulatrix, short and broad vas deferens, and simple penis with gland at distal tip. The nerve ring bears three ganglionic masses, and an additional pair of ventral ganglia connected to pedal ganglia, interpreted as odontophore ganglia. These features are discussed in light of the knowledge of other streptaxids and adaptations to carnivory.

Reference:
Simone, L.R.L., 2013. Anatomy of predator snail Huttonella bicolor, an invasive species in Amazon rainforest, Brazil (Pulmonata, Streptaxidae). Papeis Avulsos de Zoologia 53 (3): 47-58.Available at http://bit.ly/YLI1gF.

New Tentacle

Later than planned, the new issue of the Newsletter of IUCN/SSC Mollusc Specialist Group, Tentacle 21, was just released. There is a suite of short papers on Neotropical land snails, each of which I will briefly mention. Tentacle can be accessed at http://www.hawaii.edu/cowielab/Tentacle/Tentacle_21.pdf.

Maceira et al. have a paper on land snails from a floristic refuge in eastern Cuba. They noted an interesting preference of Polymita venusta colour morphs for different plant species; juveniles were mostly observed on different plants. Not having this seen reported before, this might pose a question on the relation of plant chemistry and snail feeding preferences. The average height above the ground was recorded at a single day of collecting; no explanation is provided for the observed differences, but a longer time-record of observations may be needed.

Suárez & Hernández report new detailed data on Cerion coutini from the type locality at Tako Bay in eastern Cuba.

Fernández & Franke found a relict population of the urocoptid Cochlodinella manzanillensis near Holguín, where the species was found in a very specific microhabitat of limestone outcrops in a shaded vegetated area.

Birckolz & Gernet stress the need for education of people on the difference between the introduced Achatina fulica and local Megalobulimidea.

Salvador et al. note that the five native land snails species have now joined by five invaded species. They briefly discuss the threat by goats and suggest that – since the island does not have a large permanent settlement – an inspection and quaratine program could be implemented for control.

Dos Santos et al. discuss the Red List for Brazilian non-marine molluscs, the regional differences in this vast country and the possible use of some terrestrial gastropods as flagship species for the Atlantic Forest. Also Agudo-Padrón (2013a, b) touches this subject and pleads for more data on ecology and population studies.

The relative abundance of Brazilian contributions reflects the growth in attention for land snails and their conservation in this country during the past decade. That is a hopeful sign, as there remains so much to be discovered in Neotropical malacology.

References:
Agudo-Padrón, A.I., 2013a. Threats to continental molluscs in Brasil, with special emphasis on land gastropoda. – Tentacle 21: 42-43.
Agudo-Padrón, A.I., 2013b. Non-marine mollusc conservation in southern Brasil: current situation in northwestern Rio Grande do Sul State, Upper Uruguay River basin. – Tentacle 21: 44-46.
Birkolz, C.J. & Gernet, M.V., 2013. The importance of educating people about the differences between alien Achatina fulica and native Megalobulimus paranaguensis on the coast of Paraná State, Brasil. – Tentacle 21: 9-11.
Dos Santos, S.B., Miyahira, I.G. & Mansur, M.C.D., 2013. Freshwater and terrestrial molluscs in Brasil: current status of knowledge and conservation. – Tentacle 21: 40-42.
Fernández, A. & Franke, S., 2013. First record of Cochlodinella manzanillensis (Urocoptidae) in Holguin, Cuba. – Tentacle 21: 8-9.
Maceira, D., Reyes, J., Tizón, A., González, S., Laurazón, B. & del Carmen Fagilde, M., 2013. Land molluscs and problems for their conservation in the Monte Barranga Managed Floristic Refuge, eastern Cuba. – Tentacle 21: 4-5.
Salvador, R.B., Cunha, C.M. & Simone, L.R.L., 2013. The pulmonate snails of Trindade Island, Brasil. – Tentacle 21: 38-39.
Suárez, A. & Hernández, N., 2013. Creion coutini (Pulmonata, Cerionidae) at Tako Bay Key, Baracoa, Guantánamo, Cuba.- Tentacle 21: 5-7.

Dangling Jamaican snail

Richard Goldberg posted an interesting observation on his Facebook page; see his video here: http://on.fb.me/Yf3LC5

He wrote “One of the truly bizarre behaviors of Annulariid snails is hanging by a single silken-like thread, presumably as a way to protect itself while aestivating. It was once thought that these snails were trapped by a silken thread from a spider, but it was concluded from further observations that it was in fact the snail that created the thread. From my own observations made over the past few years in Jamaica, I found that this behavior may in fact be an opportunity for the snail to expand its shell while being removed from the substrate [and predators] that would impinged its growth. The snail in the first clip was actually adding to its shell while I shot the footage. I shot the three clips in the compilation at night in December at two locations. The species here is Parachondria (Parachondrops) sauliae (Sowerby I, 1843), a 10 to 12mm species known only from the central limestone forests of the island. I have observed at least 6 other species of Jamaican Annularids doing the same thing, all at night time.”.

In the thread on his page, Tom Watters remarked “What is interesting (to me at least) is that annulariids from Curacao also suspend themselves. The difference is that the Curacao species use numerous short threads rather than one long one. A deeply rooted ancestral trait?”.
Interesting and food for thought. Of course, more observations would be needed for this hypothesis to be tested.

Conservation issues on Brazilian land snails

Ignacio Aguda-Padrón has recently published a suite of short communications on different conservation aspects of land snails in Brazil.

In a first paper (Agudo-Padrón, 2012a) he reviews briefly the effects of the introduction of the Giant African Snail on the native snail population. Abstract: A diagnostic about the conservation status of the Brazilian native land snails, severely threatened by human actions and attempts for the eradication of the invasive exotic mollusc species Achatina (Lissachatina) fulica (Bowdich, 1822) is presented. Purposely introduced in the country in 1988 for human food purposes (continental malacoculture), this species ended up being officially banned later in 2003, triggering hasty public actions, directly involving the “unprepared” Brazilian population through the means of social communication, aimed at their control and eradication of the environment. Consequence of this procedure, premature and alarmist, today many species of native and endemic terrestrial snails, poorly known scientifically, are under increased threat of extinction in Brazil and, very probably, in other South American countries.
The same data have been re-published in Agudo-Padrón (2012b).

In a second review (Agudo-Padrón, 2012c) he summarizes the available data on biogeography concerning snails in the southeastern part of Brazil and adjacent areas. Abstract: A preliminary diagnostic test summary balance sheet and rough on the marine and continental mollusc fauna, terrestrial and limnic/freshwater, occurring in the geopolitical region of the Southern Brazil and adjacent is presented. Result of extensive research work in the field and analysis of regional natural history reference generated off dilated bibliographic production, developed in the course of the last 13 years (1996~2009), aims to characterize and integral organization of their unique knowledge, emphasizing the major ecological and geographical factors that determine their presence, spatial location and occupancy of available environments. Parallels, the comparative results regarding the total numbers of species estimated for each of the portions of the territory geo-spatial components analyzed, the Brazilian states of Paraná (PR, 332), Santa Catarina (SC, 772), Rio Grande do Sul (RS, 492), and the neighboring countries of its southern Uruguay (373) and Argentina (535), members as a whole so-called Atlantic Slope region of the Southern Cone of South America, to the West of the Andes.

Finally, a recent publication summarizes the conservation status of terrestrial snails, both as recognized by the IUCN and by local Brazilian authorities (Agudo-Padrón, 2013).

Seemingly in consensus, if one accept that the same criteria have been used, it is remarkable that IUCN recognized a more severe category in six cases. In two cases no joint data are available and in two other cases their judgement of the situation is identical. Only in the case of Gonyostomus insularis the Brazilian verdict ranks this species in a higher category. One can only guess what is the different reasoning behind all this.

References:
AGUDO-PADRÓN, A.I. 2012a. Dangerous brazilian environmental controversy involving exotic and native land snails. International Journal of Biology and Biological Sciences, 1(1): 1-4. Available online at:http://academeresearchjournals.org/journal/ijbbs/archive
AGUDO-PADRÓN, A.I. 2012b. Conservation situation of native land snails threatened by “actions for eradication” of exotic species in Brazil, South America. Biological Evidence, 2(1): 1-2. Available online at:http://bio.sophiapublisher.com/html-464-40-be
AGUDO-PADRÓN, A.I. 2012c. Mollusc fauna in the Atlantic Slope region of the Southern Cone of South America: a preliminary biogeographical interpretation. International Journal of Aquaculture, 2(4): 15-20. Available online at: http://bio.sophiapublisher.com/html-442-33-ija
AGUDO-PADRÓN, A.I. 2013. Effective knowledge and conservation of continental molluscs in Brazil, South America, with special emphasis in gastropods: the current situation. Journal of Biodiversity Management & Forestry, Henderson/ Nevada, 2(1): 1-2. Available online at:http://www.scitechnol.com/JBMF/JBMF-2-103.pdf

Berlin types and handwritings

Just published: a paper on the Orthalicoid types in the Berlin museum, together with data on labels and handwriting based on part of the correspondence archived in the museum.

The paper may be found in ZooKeys 279 (link: http://bit.ly/14pEoB5).

Mollusca 2014

From 23-27 June 2014 the conference “Mollusca2014: The Meeting of the Americas” will be held in Mexico City. It is a joint meeting of ALM, SMM (Latin American malacologists), AMS and WSM (North American malacologists). The first circular has just been sent out and is available here in English, Spanish and Portuguese at: http://sbnature.org/crc/805.html.

I’m sure that someone will step up to organize a symposium on Neotropical land snails during the conference 🙂