Category Archives: Uncategorized

A new Peruvian Sultana

Just published: a new Peruvian species of Sultana, published by two Spanish authors, Ahuir and Torres.
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The species is described from northern Peru, Dept. Piura, near Huancabamba on the border with Ecuador. Unfortunately the picture given is quite dark, but it shows the characteristic pink lip and the white inside of the aperture well enough. The holotype will be deposited in the Paris museum.
Thanks to Philippe Bouchet who sent me the paper.

Reference:
Ahuir Galindo, J. & Torres Alba, J.S., 2019. One new terrestrial gastropod species from Peru. – Malacologia Mostra Mondiale, 104: 3-4.

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Avoiding canopy gaps

Only now a paper turned up which was already published in 2014. Bloch & Stock reported on a Puerto Rican species from the Solaropsidae related to ecological research. Unfortunately the paper is text-only…

The abstract is “Because canopy gaps are characterized by elevated temperature and decreased humidity relative to closed-canopy forest, terrestrial gastropods may be exposed to greater desiccation stress in gaps than in undisturbed forest. We placed individuals of Caracolus caracolla at the edges of canopy gaps in montane forest in Puerto Rico and observed their movements. Individuals preferentially moved out of gaps except in one gap on the first night of the study, and the proportion of individuals recaptured inside gaps decreased over time. Individuals moved, on average, farther into forest than into gaps. Juveniles and adults responded similarly. These results suggest that C. caracolla actively avoids canopy gaps, and that its activity and ability to disperse are restricted in a post-disturbance environment“.

Reference:
Bloch, C.P. & Stock, M., 2014. Avoidance of Canopy Gaps by a Common Land Snail, Caracolus caracolla (L.), in Montane Forest in Puerto Rico. – Caribbean Naturalist, 8: 1-13.

Rediscovered Bermuda species

When we consider Bermuda on the outskirts of the Neotropics, this information might be relevant:

Bermuda land snail: An animal ‘back from the dead’

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Thousands of critically endangered snails have been released into the wild after being rescued from the edge of extinction, with a little help from a British zoo.

The greater Bermuda land snail was thought to have disappeared for many years until an empty shell turned up in the territory’s capital city, Hamilton.

Live snails were then found among litter in a nearby alleyway.

Some were flown to Chester Zoo for a unique breeding programme.

More than 4,000 snails raised at the zoo have now been taken back to the island and released.

Many more captive snails will soon be returned to their homeland to help give the species a new lease of life.

Mark Outerbridge, a wildlife ecologist for the Bermuda government, said the snail was a “Lazarus species”, which was considered extinct not so long ago.

Then, in 2014, a man walked into his office in the capital, Hamilton, holding a fresh snail shell.

 

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“It turned out that, yes, this was in fact the greater Bermuda land snail, a species that we thought had gone extinct 40 years earlier,” he said.

“He came back the next day with a fresh one, a live one in his hand, and that’s how I was thrust into this conservation project.”

A small but thriving population of land snails was discovered behind a restaurant. The gastropods were living among litter – specifically inside thrown-away plastic bags – in a “dank wet alley”, surrounded by four-storey buildings.

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Water dripping from air conditioning units had created an environment where the animals could survive unnoticed.

“It turned out that the plastic bags were one of the favourite places for these snails to hang out, because of course it retained the moisture the best – and the snails are very vulnerable to drying out,” said Dr Outerbridge.

“And when we started picking up these plastic bags and unfolding them – literally they contained hundreds of juveniles and hatchling-sized snails.”

Some of the hatchlings were taken into captivity for breeding. Their offspring were later sent to Chester Zoo and the Zoological Society of London, where scientists were able to establish colonies.

It turns out that the snails are prolific breeders in captivity, with thousands of snails bred in a matter of years.

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“At the last count we’ve got somewhere around 13,000 snails – we’ve probably got more than that, they’ve had a lot of babies since then,” said Amber Flewitt, of Chester Zoo, who cares for the snails.

The secret of breeding success, she said, was nice soil and their favourite foods, which include sweet potato and lettuce.

Thousands of the Chester Zoo snails have now been sent back to Bermuda for release in nature reserves.

The snails are thought to be doing well in their new home.

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Dr Gerardo Garcia of Chester Zoo said that, following three years of intensive work, the zoo was proud to see the snails heading home.

“This is an animal that has been on this planet for a very long time and we simply weren’t prepared to sit back and watch them become lost forever when we knew we might be able to provide a lifeline,” he said.

The greater Bermuda land snail is unique to Bermuda and is part of an ancient lineage of land snail that dates back in time over one million years.

Once abundant on the islands that make up the territory of Bermuda, the population went through a dramatic decline during the 20th Century after being preyed on by invading killer snails.

The snails have been released on a nature reserve on the northern Nonsuch Island, which has snail-friendly habitats and no evidence of the main predators that nearly caused the animal’s demise.

They will join a small wild population, estimated at a few hundred individuals. This makes the species more rare in the wild than the likes of the giant panda or mountain gorilla, according to Chester Zoo.

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Some captive individuals have been fitted with fluorescent tags to monitor their recovery in the wild.

“Not only did they escape the axe of extinction but they have rebounded so well in captivity through breeding that now what we’re doing is we’re identifying islands in Bermuda that don’t have the predators and reintroducing them to those islands, and our expectations are very high that they’ll do well,” said Dr Outerbridge.

In the case of this species, it was a matter of having to look literally under every rock and every log before writing the animal off, he added.

The original article, including some videos, can be found here.

Improving citizen science projects

Citizen sciences projects are becoming more and more popular with scientists to expand their capacity to collect data. Yet, there are ways to further improve this ‘tool’ as Callaghan et al. argue in their just published (open access) paper.

Their abstract reads: “Citizen science is mainstream: millions of people contribute data to a growing array of citizen science projects annually, forming massive datasets that will drive research for years to come. Many citizen science projects implement a “leaderboard” framework, ranking the contributions based on number of records or species, encouraging further participation. But is every data point equally “valuable?” Citizen scientists collect data with distinct spatial and temporal biases, leading to unfortunate gaps and redundancies, which create statistical and informational problems for downstream analyses. Up to this point, the haphazard structure of the data has been seen as an unfortunate but unchangeable aspect of citizen science data. However, we argue here that this issue can actually be addressed: we provide a very simple, tractable framework that could be adapted by broadscale citizen science projects to allow citizen scientists to optimize the marginal value of their efforts, increasing the overall collective knowledge”.

journal.pbio.3000357.g001

Also in malacology several projects are known that use(d) this tool of citizen science, mostly known in the northern hemisphere. While in the southern hemisphere (Neotropics, Asia, Africa) the lack of sufficient biodiversity data is more prominent and the number of professional researchers is comparatively low, the potential for well-organised citizen projects may be larger. Something to consider for malacologists out there?

Reference:
Callaghan, C.T. et al., 2019. Improving big citizen science data: Moving beyond haphazard sampling. PLoS Biol 17(6): e3000357. https://doi.org/10.1371/journal.pbio.3000357

Pantepui snails

Just published: a chapter on the land snails of the Venezuelan Pantepui region. It is a slightly updated summary of what was published some years ago, while in the meantime only slight progress was made.

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For the species reported hitherto from this area the taxonomy is summarised, and data on the ecology and biogeography is presented.

The rest of the book presents a lot of information on this interesting area of South America, both general and on the flora and fauna. The illustrations are plentiful and often spectacular.

Reference:
Breure, A.S.H., 2019. Land snails: an updated summary: 247-261. — In: Rull, V., Vegas-Villarrúbia, T., Huber, O. & Señaris, C. (eds.) Biodiversity of Pantepui: the pristine ‘Lost World’ of the Neotropical Guayana Highlands. Academic Press, Cambridge

Historical range information

A paper just published by Salvador provides interesting information on some distribution ranges based on a historical collection. The abstract reads “The malacological collection of the Museum of New Zealand Te Papa Tongarewa (NMNZ), despite naturally focusing on New Zealand species, also includes a variety of specimens from South America. Examination of this material revealed new distributional data for several species. All Brazilian, Uruguayan and Argentinian terrestrial gastropods from the NMNZ collection were examined and re-identified (no material from Paraguay was found). The information gathered was compiled and is presented in this article, and may contain significant data for malacologists working with the region’s fauna. In summary, 99 species are reported, 13 of which represent new records and meaningful increments in geographical distribution, either extending their known range or filling distributional gaps. Moreover, the NMNZ collection houses the type material of six species from Brazil and Argentina described by the New Zealand malacologist Henry Suter (1841–1918) in 1900“.

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The material consists of species from 17 families. “The following 13 species have significant increments in their distribution (range extension or filling of distributional ‘gaps’): Auris chrysostoma, Auris illheocola, Auris melanostoma and Thaumastus nehringi (Bulimulidae [Thaumastus belongs to the Megaspiridae]); Callionepion iheringi (Megaspiridae); Cyclodontina fusiformis, Moricandia willi and Spixia martensii (Odontostomidae); Simpulopsis decussata (Simpulopsidae); Neobeliscus calcarius (Achatinidae); Happia iheringi (Scolodontidae); Epiphragmophora hieronymi (Epiphragmophoridae); and Solaropsis punctatus (Pleurodontidae) [sic, Solaropsidae]“. The author rightly draws attention to the fact that even historical collections – although sometimes lacking from precise data – can contribute to our knowledge of distribution of species. This being said, however, it also points to the insufficient inventories being made on a detailed scale in many of the Neotropical countries which leads to insufficient insights in the distribution of many species.

Reference:
Salvador, R.B., 2019. Brazilian, Uruguayan and Argentinian terrestrial gastropods in the collection of the Museum of New Zealand Te Papa Tongarewa. – Tuhinga, 30: 82-98.

How ‘lefties’ are initiated

In some snails it occasionally occurs, in others it is more frequent, and in a few families (e.g. Clausiliidae) it is the norm: sinistral shells or ‘lefties’.

Also in the Neotropics this can be found. Clausiliids occur mainly in the Andean countries, and groups with some genera where sinistrality more or less frequent does occur are e.g. Corona and Drymaeus. But the genetic mechanism behind this phenomenon is now slowly unraveled. See the story behind the link below…

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