Tag Archives: brazil

Fossil connections

Recently a review paper appeared by Hammouda et al. (2017), in which some links between northern Africa and South America are suggested. The abstract is as follows:

“Terrestrial gastropods occur in many North African localities in Eocene continental deposits. Here we analyse the faunal assemblage from the Hamada de Méridja Formation in southwestern Algeria, dated as Early to Middle Eocene on the basis of charophytes. The assem- blage consists of three closely related species that to date have been classified either in the extant Madagascan genus Leucotaenius v. Martens, 1860, or in the SW European Eocene genera Romanella Jodot, 1957 and Vicentinia Jodot, 1957. This is rejected for shell morphological and phylogeographical reasons, and a new classification as Maghrebiola gen. nov. is proposed. Maghrebiola is tentatively placed in the South American family Strophocheilidae, as species from the Early Eocene Itaboraí Basin of Brazil, currently placed in the genus Eoborus Klappenbach and Olazarri, 1970 in the family Strophocheilidae, superfamily Acavoidea, have a very similar shell habitus. This record possibly extends the known geographical range of the Strophocheilidae into the African continent during the Eocene. Immigration of this stock into North Africa during the Cretaceous via a still existing plate connection is assumed. An attribution of Maghrebiola to the African family Achatinidae is unlikely for shell morphological reasons despite certain habitus similarities, although the Priabonian genera Arabicolaria and Pacaudiella from Oman most likely belong into this family, and not to the Vidaliellidae as originally proposed. Possible causes for the very low diversity of the assemblage are mainly unfavourable living conditions, i.e. a relatively dry climate resulting in sparse vegetation and only occasional presence of water bodies, which may have had increased salinities, accounting for the lack of freshwater mollusks. The absence of any competing large gastropods may possibly have facilitated high intraspecific variability leading to sympatric occurrence of three closely related species, due to the animals occupying a wide range of available ecological niches. As the species discussed here have also been attributed to the genera Romanella and Vicentinia in the Vidaliellidae, we provide an appendix with annotated characterisations of most genera of the Vidaliellidae and list the nominal species assigned to them. This family is tentatively placed in the South American superfamily Orthalicoidea; its stock would have similarly immigrated from South America, but have successfully colonized mainly SW Europe, with only one Eocene species [Romanella kantarensis (Jodot, 1936)] recognized in Algeria”.

This paper presents a provoking view on the relations between northern Africa, soutwestern Europe and South America during the Eocene. Perhaps food for discussion among palaeontologists?

Reference:
Hammouda, S.A., Kadolsky, D., Adaci, M., Mebrouk, F., Bensalah, M., Mahboubi, M. & Tabuce, R., 2017. Taxonomic review of the ‘‘Bulimes’’, terrestrial gastropods from the continental Eocene of the Hamada de Méridja (northwestern Sahara, Algeria) (Mollusca: Stylommatophora: Strophocheilidae?), with a discussion of the genera of the family Vidaliellidae. – Paläontologische Zeitschrift, 91: 85-112.

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Reproductive biology of a Megalobulimus species

Fontenelle & Miranda have just published a paper on Megalobulimus. Their abstract reads “We studied the reproductive biology of Megalobulimus paranaguensis (Pilsbry & Ihering, 1900), a large and long-lived land gastropod from the Atlantic Rainforest of Brazil. The study was conducted at an urban park in the city of Santos, state of São Paulo. For 4 years, we counted the egg postures and annual eclosion rate of 32 captive snails and looked for associations between egg posture and the climatical variables of the period. The annual mean posture of 8.7 eggs per snail obtained in our results is a small number, but typical of Brazilian macromollusks. The annual eclosion rate was 31%. The beginning of the annual activity period of snails occurred in the middle of March, and lasted 33.97±3.02 weeks. The dormancy period started in the beginning of November, and lasted 18.39±3.11 weeks. There were two egg posture peaks, a minor peak between March and May, and a major peak between August and November, with greater values in September. Megalobulimus paranaguensis has a well-defined seasonal reproductive pattern influenced by environmental temperature and temperature range. Furthermore, in this snail, reproduction is negatively influenced by temperature increasing and temperature range”.

Schermafbeelding 2017-04-06 om 20.55.36

Reference:
Fontenelle, J.H. & Miranda, M.S., 2017. Aspects of biology of Megalobulimus paranaguensis (Gastropoda, Acavoidea) in the coastal plain of the Brazilian southeast. – Iheringia, Zoologia, 107: e2017004 (5 pp.). DOI: 10.1590/1678-4766e2017004

A new Oxychona from Bahia

The Journal of Conchology has recently published some papers relevant to Neotropical land snails. Today, I mention the paper by Porto et al. (2017) about Oxychona.

The abstract reads “A new species of Oxychona was found during excursions to the Michelin Ecological Reserve (13°S), Southern Bahia State (Northeastern Brazil), which comprises an Atlantic Rainforest Conservation Unit. Living snails and empty shells were collected from ground litter accumulations and kept in an artificial environment supplied with local water and sediment, feeding on leaves of almond tree (Terminalia catappa L.). The new species is described and compared with others from adjacent areas of Brazil between 13oS and 15oS including O. bifasciata, O. currani and O. maculata. Oxychona n. sp. is likely to be endemic to Bahia State, thus supporting the biodiversity and rates of endemism of pulmonate molluscs to the Tropical Atlantic Rainforest in Southern America”.

This is a very nice paper as the authors have taken the effort to include a key to Oxychona species. So, although this paper only described a single new species, it still has broader application. The authors also give anatomical and ecological details.

The main author, Beth Neves, was kind enough to send me a short film of a living specimen of the new species, which I’m happy to share here.

Reference:
Porto, R., Rocha Filho, R. da, Johnsson, R. & Neves, E., 2016. New species of Oxychona (Bulimulidae) from Michelin Ecological Reserve (Bahia State, northeastern Brazil. – Journal of Conchology, 42: 105-110.

Two papers on CCP snails

Two papers were published, one very recently and one today, related to the material collected by the ‘Comisión Científica del Pacífico’ (CCP). This material was collected during an expedition that lasted from late 1862 to  early 1866 through several Neotropical counties. The material has been deposited in the Madrid museum and was originally studied by Hidalgo (terrestrial molluscs, marine gastropods) and Martínez (marine bivalves).

The terrestrial material has been restudied during a SYNTHESYS project last year, and has resulted in two papers. One dealing with the CCP material and the history of the expedition (Breure & Araujo, 2017), and one dealing with the publication date of Hidalgo’s main paper on the CCP material and related correspondence from him with Crosse in Paris (Breure & Backhuys, 2017).

The link to the first paper is here.

Update:
Due to an unfortunate coincidence at the proof stage (we unexpectedly received only one proof), the following corrections were not made in the published version:
Fig. 3 in the text (page 4) correspond to Fig. 2B
Fig. 4 in the text (page 5) correspond to Fig. 3A
Fig. 5 in the text (page 6) correspond to Fig. 3B
Fig. 6 in the text (page 6) correspond to Fig. 4A
Fig. 7 in the text (page 7) correspond to Fig. 4B
Fig. 8 in the text (page 9) correspond to Fig. 5A
Fig. 9 in the text (page 10) correspond to Fig. 5B
Fig. 10 in the text (page 12) correspond to Fig. 6A
Fig. 11 in the text (page 12) correspond to Fig. 6B
Then, after Fig. 11 in the text, appear Figs. 7A-7B (page 17) that actually correspond to the Figures 7A and 7B; later (page 17) appears Fig. 8G-8H that correspond to Fig. 8.
Finally, Fig. 27H does not depict Bostryx rouaulti as the wrong shell was photographed.

References:
Breure, A.S.H. & Araujo, R. The Neotropical land snails (Mollusca, Gastropoda) collected by the ‘Comisión Científica del Pacífico’. — PeerJ 5: e3065 (142 pp.).
Breure, A.S.H. & Backhuys, W. Science networks in action: the collaboration between J.G. Hidalgo and H. Crosse, and the creation of ‘Moluscos del Viaje al Pacifico, Univalvos terrestres’. — Iberus 35: 11–30.

Brazilian cave snails

Another freshly pressed paper is by Salvador et al. on Brazilian cave snails. The abstract reads “A sample of land and freshwater snails, mainly pulmonates, was recently collected in caves in Goiás and Bahia states, Brazil. Twenty-one species were found in the material. The following species are reported for the first time for Goiás state: Cecilioides consobrina (Ferussaciidae), Dysopeas muibum and Stenogyra octogyra (Subulinidae), Entodina jekylli and Prohappia besckei (Scolodontidae; also reported for the first time for Bahia state), Pupisoma dioscoricola (Valloniidae). A new species from Goiás is described here-in: Gastrocopta sharae sp. n. (Gastrocoptidae). The new records and species addressed here constitute important findings, helping to fill distributional gaps and improving the knowledge of the local molluscan fauna, an essential step for future conservation efforts”.

schermafbeelding-2017-02-19-om-06-18-59

Besides the species newly reported for the two states, there are also additional records of the following land snails: Helicina angulata Sowerby, 1873 (Helicinidae), Cyclodonta sexdentata (Spix in Wagner, 1827) and Ringicella luetzelburgi Weber, 1925 (Odontotomidae), Happia glaberrima Thiele, 1927 (Scolodontidae), Allopeas micra (d’Orbigny, 1835) and Leptinaria concentrica (Reeve, 1849) (Subulinidae); five species are identified only to genus level.

This study complements earlier studies on the cave malacofauna in Brazil from part of the authors (see here and here).

Reference:
Salvador, R.B., Cavallari, D.C. & Simone, L.R.L., 2017. Taxonomical study on a sample of land and freshwater snails from caves in central Brazil, with description of a new species. – Zoosystema and Evolution, 93 (1): 193-141.

New record for Mirinaba

A new locality has been recorded for the species Mirinaba jaussaudi (Morretes, 1937) from Paraná state in Brazil.

schermafbeelding-2017-01-23-om-07-41-15

This species is now known from different ecoregions.

Reference:
Birckolz, C.J. & Gernet, M.V., 2016. New record of Mirinaba jaussaudi (Gastropoda, Strophocheilidae) in Paraná state, southern Brazil, and rectification of a known locality. – Strombus 23(1-2): 1-5.

Subterranean hotspots

Cave systems are always an interesting place for biologists to see what animals live there and might have adapted themselves to a subterranean life. According to Silva & Ferreira (2016) “[t]he term hotspots of subterranean biodiversity has been used to define subterranean habitats with an arbitrary cutof of twenty or more obligate stygobitic and troglobitic species. Until present, no hotspots of subterranean biodiversity had been identified in South America. Thus, the objective of this work is to present the first two hotspots of subterranean biodiversity in that continent. The two hotspots of subterranean biodiversity are the Toca do Gonçalo cave (22 spp.) and Areias cave systems (28 spp.). The cave species, some of them considered relict species, belong to the Platyhelminthes (1 sp.), Nemertea (1 sp.), Gastropoda (2 spp.), Amphipoda (2) Isopoda (7), Decapoda (1), Collembola (5), Coleoptera (5), Ensifera (1), Sternorrhyncha (1), Zygentoma (1), Diplopoda (6) Chilopoda (5) Araneae (2), Opiliones (1) Palpi- gradi (2), Pseudoscorpiones (4), and Osteicthyes (2). Although both caves, together, have 50 troglobitic species, only 38% of these species are formally described. Both caves have perennial water bodies, but terrestrial obligate cave invertebrates are dominant in number of species in both systems (around 77%). While the Areias system is partially contained in a conservation unit, Toca do Gonçalo cave is currently unprotected, although it certainly deserves protection”.

schermafbeelding-2017-01-05-om-13-37-26

One terrestrial species was found, Rotadiscus sp. Other recent reports on snails from caves may be found here and here.

Reference:
Silva, M.S. & Ferreira, R.L., 2016. The first two hotspots of subterranean biodiversity in South America. – Subterranean Biology, 19:1-21.