Endangered snails

Land and freshwater snails are the animals most susceptible to extinction, due to their usually small geographic distribution, their low mobility and their usual habitat specificity. Many Brazilian species are certainly critically endangered, but the lack of studies makes it impossible to include them in the so-called “Red List” for conservation, which demand a higher amount of information. Thus, studying these snails, cataloging them, defining their distribution and understanding their habitat requirements are critical for conservation efforts.

Brazil is a megadiverse country and its flora and fauna may still hide important discoveries. Some still undiscovered species might have commercial or medical importance in the future. Some might already be extinct or on the brink of extinction. But besides the material importance of species, we have also a duty of preserving the ecosystems for their own intrinsic worth.

During my research, I have encountered some cases worth mentioning. They are all described below, with exception of the snails from Trindade Island, which needed a separate section [HERE].


Extinct before described

Leiostracus (Nanuque) 1
The new species of Leiostracus.

The southeastern region of Brazil is historically the most explored and exploited in the country. Still, many new discoveries wait in the remnants of Atlantic Forest. A sample of land snails was recovered in the region of Nanuque (in northern Minas Gerais state) and included some new species.

One of these new species is a striking Leiostracus snail (family Bulimulidae), whose shell bears spiral bands of black, brown, yellow and/or red color. Shells with distinct color patterns are not uncommon in the genus, but they usually comprise only varying tones of yellow and brown, but this new species shows a lot more variation in color. These snails are usually found on trees or tall bushes and it remains unknown whether their remarkable color pattern is related to camouflage, aposematism, or if it indeed plays some role on the animals’ lives at all (still, many specimens show signs of predation by birds).

Leiostracus (Nanuque) 2
The large amount of variation in shell color pattern (shell height ca. 23 mm).

The precise place where the Nanuqe snails were collected was a very small fragment of Atlantic Forest in the vicinities of the city, close to the Mucuri River and surrounded by tomato crops. A couple of weeks after our manuscript (which described all the new species) was submitted, we received very alarming news: the forest fragment was devastated in order to open space for more crops. Whether the new species we were describing in the manuscript (including the striking Leiostracus shown here) have already become extinct remains to be seen, as they may still thrive unknown and undisturbed in other localities.

This story serves as a clear reminder that many species are becoming extinct before been even known to science. The sparse remnants of Atlantic rainforest can be, in many cases, centers of diversity and perhaps even endemism and might act as refuge for many species. These forest fragments clearly require protection and appropriate legislation. The knowledge of the local fauna of each place is usually the first step towards this goal, but sometimes science proceeds much more snail-paced than agriculture and industry and, thus, more aggressive protection measures might be required.

The species finally received its scientific name in April-2016: Leiostracus carnavalescus.


Known only from a museum specimen

Leiostracus faerie
Leiostracus faerie (shell height 14.6 mm).

An extraordinary new species of land snail was fortuitously found in the collection of the Naturmuseum Senckenberg (Frankfurt am Main, Germany) while browsing through the specimens of the genus Leiostracus (family Bulimulidae). The new species was described as Leiostracus faerie Salvador & Cavallari, 2014, receiving this name for its fairy-like small and ethereal shell. The species is represented by a single shell, which is part of an old collection (1914) from the Doce River region (in Espírito Santo state, Brazil), an area of known high diversity and endemism of many animal groups.

Unfortunately, this single specimen of L. faerie was collected a century ago and it is not possible to know whether L. faerie can still be found in the wild, given the major degradation of the Atlantic Forest. Finding this new species in an old collection is a good reminder of how important museum collections are, not only for information storage but also for new discoveries.


Bibliography

The preceding text is a summary of the following papers, where this research was published:

  • SALVADOR, R.B. & CAVALLARI, D.C. 2014. A new species of Leiostracus (Gastropoda, Pulmonata, Orthalicoidea) from Espírito Santo, Brazil. Iheringia, Série Zoologia, 104: 364-366.  [PDF]
  • SALVADOR, R.B. & SIMONE, L.R.L. 2015. The discovery and possible extinction of a Leiostracus land snail in southeastern Brasil. Tentacle 22: 7-8.  [PDF]
  • SIMONE, L.R.L. & SALVADOR. 2016. Taxonomical study on a sample of land snails from Nanuque (Minas Gerais, Brazil), with descriptions of three new species. Stuttgarter Beiträge zur Naturkunde A, Neue Serie 9: 9–30.  [PDF]
Advertisements