Deep beneath the ocean surface, where no sunlight can penetrate, there are areas so hot, volatile and toxic that it's hard to believe life can exist...but it does, and often in abundance. It is exactly this kind of hostile environment that one of our most recent natural history acquisitions came from, a spectacular marine snail called the 'scaly-foot gastropod', or for those of you who like Greek and Latin, Chrysomallon squamiferum Chen, Linse, Copley & Rogers, 2015 (fig. 1). It comes from depths of 2785m, living on the edge of hydrothermal vents and black smokers that reach temperatures of 300-400°C. This is certainly not your average snail...

Under armour and ready for battle

It was in 2000 that the first hydrothermal vent field was discovered in the Indian Ocean, known as Kairei field, and a year on that Woods Hole surveyed the area in the RV Knorr 162-13 and encountered this new species. It was immediately obvious that something unique had been discovered. The 'foot' of this snail, which is the fleshy soft part that snails move around on, displayed hundreds of hardened tags, almost like an armour. These tags are called sclerites; fleshy in the centre and hard on the exterior due to a layer of conchiolin (a protein secreted as a part of shell formation) covered by a layer of iron sulphide that gives it a black metallic appearance (fig. 2). The iron sulphide exists in two forms in the snail: greigite, which is highly magnetic, and pyrite, which is commonly known as fool's gold. The presence of the metallic sclerites is not totally understood but Suzuki et al. at the Extremobiosphere Research Center in Japan suggest the snail may control the mineralization of the iron sulphides for protection from crab predation or perhaps for detoxification purposes.

Completely unique is that the iron sulphide is also found in the snails' shell, so this was the first discovery of an animal with iron sulphide in its skeleton (fig. 3). Underneath the metallic exterior there is a thick but softer organic layer which covers the hard calcium carbonate shell that most marine snails have. So unusual is this triple layering in the shell, in both its chemical make-up and mechanism, that some scientists consider it to offer extensive protection and think it may be used as inspiration for man-made armour in the future.

New vent fields, new discoveries

The iron and sulphide found in the scaly-foot gastropods at the Kairei field comes from the mineral rich waters expelled from the hydrothermal vents and black smokers. Different vents do, however, have different mineral compositions. Nevertheless, it was still of great surprise when in 2009 the Solitaire field was discovered in the Indian Ocean and living on it was a different colour form of the scaly-foot gastropod; this time displaying a brown shell and cream coloured sclerites, both completely lacking the iron sulphide coating. Genetic testing by Nakamura et al. at the Precambrian Ecosystem Laboratory in Japan confirmed in 2012 that they are the same species and also that the sclerites of the iron-lacking form were in fact mechanically stronger. Then, in 2011, yet another population of the black scaly-foot gastropod was found in great abundance at the Longqi field, another new discovery for the Indian Ocean, and this is where the two specimens deposited at this museum came from. Figure 4 shows snails from the three different vent populations.

The heart of a dragon

The external features of this snail are certainly spectacular and strange, but taking a look inside shows that the theme continues there. It is of no surprise that this snail has special adaptations to live in such a toxic and harsh environment; survival in such a place certainly requires an evolutionary helping hand. Similarly to other species living on black smokers and close to vent effluents it has evolved a symbiotic relationship with bacteria living inside its body. These bacteria supply the snail with most of its nutrition and to accommodate them the snail has developed a massive oesophageal gland, taking up over 9% of its body mass! In turn the snail needs to keep the bacteria alive and so has also developed a huge circulatory system, including a supersized heart, to supply the oesophageal gland with enough oxygen. It's a win-win situation, or perhaps a deal made in Hell!

What's in a name?

Although it was discovered 14 years ago it is only this year that the scaly-foot gastropod was officially christened Chrysomallon squamiferum by Chong Chen of Oxford University and his associates. This snail is so different to any others known that Chen et al. needed to describe a new genus to put this new species in. The genus name Chrysomallon means 'golden fleece', giving reference to the metallic coating often containing fool's gold. The species name squamiferum means 'scale-bearing', making obvious reference to the sclerites covering the foot of the snail. The process of describing new species also means that a specimen (holotype) or a series of specimens (holotype and paratypes) need to be selected as representatives of the species and placed in museum collections, and that is where we come in! The two specimens we have been donated are a part of this incredibly important 'type' series. They even came with a note telling us to store them in 100% alcohol as any water in the preservative would cause them to rust over time. Rusting is certainly not a conservation issue we usually have to consider with our mollusc collections!

Back at the museum

This is not the first addition of molluscs from deep sea hydrothermal vents to our collections. With resident bivalve researchers working here we already house material that has been described by our experts from such environments, in addition to other extreme marine environments. Some are from the oil seeps off Louisiana in the Gulf of Mexico, the mud volcanoes in the Gulf of Cadiz or methane seeps off Chile. Others are from hydrothermal vents on the Northern Mid-Atlantic Ridge and hydrothermal springs in the Cascadia Basin of the NE Pacific. Perhaps the strangest place that one of our new species was described from was the wreck of the sunken ship Francois Vieljeux which contained organic cargo containing sacks of beans, sunflower seeds and bales of sisal twine. Over time the rotting cargo produced a sulphur rich environment that attracted animals able to exploit it, including the bivalve Spinaxinus sentosus Oliver & Holmes (fig. 5). Amazing.

When you think that only 160 years ago much of the scientific community embraced Edward Forbe's 'azoic theory', that life could not exist beyond 550m, our knowledge and understanding of the sea has really come on a very long way. Nevertheless, there will always be more waiting to be discovered.

If you want to learn more about our collections follow us on Twitter @CardiffCurator

References:

Chen, C., Copley, J. T., Linse, K., Rogers, A. D. and Sigwart, J. (2014). Abstract from Seventh Congress of the European Malacological Societies. Edited by White, T. S.

Chen, C., Linse, K., Copley, J. T. and Rogers, A. D. (2015). The 'scaly-foot gastropod': a new genus and species of hydrothermal vent-endemic gastropod (Neomphalina: Peltospiridae) from the Indian Ocean. Journal of Molluscan Studies. 81(3): 1-13. doi:10.1093/mollus/eyv013

Nakamura, K, Watanabe, H, Miyazaki, J, Takai, K, Kawagucci, S, et al. (2012). Discovery of New Hydrothermal Activity and Chemosynthetic Fauna on the Central Indian Ridge at 18u-20uS. PLoS ONE 7(3): e32965. doi:10.1371/journal.pone.0032965

Oliver, P. G. & Holmes, A. M. (2006). New species of Thyasiridae (Bivalvia) from chemosynthetic communities in the Atlantic Ocean. Journal of Conchology. 39(2): 175-183; figs 1-32.

Suzuki, Y. et al. (2006). Sclerite formation in the hydrothermal-vent 'scaly-foot' gastropod - possible control of iron sulphide biomineralization by the animal. Earth and Planetary Science Letters 242. 39-50.

Yao, H. et al. (2010). Protection mechanisms of the iron-plated armor of a deep-sea hydrothermal vent gastropod. Proceedings of the National Academy of Sciences 107.3 (2010): 987-992. http://dx.doi.org/10.1073/pnas.0912988107

Every week we tweet about molluscs on #MolluscMonday via our @CardiffCurator Twitter account. This is a great opportunity for us to showcase some of the amazing specimens in our collections at the Natural Sciences Department of National Museum Cardiff. We also talk about some of the research work we do and highlight some of the fantastic molluscs that are out there.

So why not find out what we have been tweeting about over the last few months in our latest Storify Story 'Stunning Shells'.

If you find these interesting you can also follow us on Twitter.

And why not follow our Natural History conservators as well @NatHistConserve

St Brigid’s primary in Denbighshire won a trip to The National Slate Museum in Llanberis and a day of nature based activities as their prize for participating in the Spring Bulbs in schools project 2014-15. St Brigid’s year 6 class worked very hard on the project this year, taking daily weather readings and sending these in weekly to the Amgueddfa Cymru - National Museum Wales website. Each pupil cared for their plants and entered their individual flowering dates and heights to the website.

It was very hard to choose winners this year, as many schools had complete or near complete weather records. To make the decision fair the top schools were entered into a hat and a winner picked out at random for Wales, England and Scotland. Those that were not picked out became the ‘runners up’ who each received £40 gift vouchers to spend on gardening resources for their schools. The ‘highly commended’ schools received meadow resource packs, meadow seeds and sunflower seeds. The ‘special recognition’ schools received meadow resource packs and meadow seeds. All schools who entered data were awarded Super Scientist certificates and pencils in recognition of the fantastic work they have done for National Museum Wales through taking part in the investigation. 

St Brigid’s visited Llanberis on 22 May, where they were greeted by Dafydd Roberts the Museum’s Keeper and myself, the Spring Bulbs Project Co-ordinator. We began by discussing the project results for 2014-15 and comparing these to previous years. You can study the report summary 2005-2015 for yourself here.

Next, we were escorted to the Quarrymen’s Cottages at Fron Haul and given a fascinating overview by Wyn Lloyd-Hughes of how life for the inhabitants would have changed over the course of 100 years. This was a fantastic way of bringing the stories and lives of the families associated with the local slate industry alive and the group enjoyed exploring the houses and discussing differences in décor and possessions between 1861, 1901 and 1969.

Following Fron Haul, we rushed over to the yard for a short introductory film about the history of the North Wales slate industry; ‘To Steal a Mountain’. This was very atmospheric, with the class falling silent as the lights dimmed and gasping at dramatic (or loud) intervals in the film. This was followed by a slate splitting demonstration by Carwyn Price, who split and dressed slate in front of the group. We watched as he split slate tiles and dressed slate into the shape of a heart. He showed us other examples of art that could be created with these methods, such as fans and love spoons. Carwyn offered the audience a chance to try their hand at slate splitting and the class nominated their teacher Mr Madog! He did a great job and was cheered throughout by the class.

Next, Peredur Hughes took us for a tour of the Museum’s working water wheel and explained the process that turned it and how this power was harnessed to operated machines in the Gilfach Ddu workshops. This is the largest water wheel on the British mainland with a diameter of 15.4 meters, and was used between 1870 and 1925 when it was replaced by a Pelton wheel. Standing under the wheel as it sprays water, gently groans and continually turns is quite an experience, especially when you begin to comprehend the engineering skills needed to design and build it. As part of the Spring Bulbs project schools are provided with resources to aid discussions around climate change and different energy sources - seeing a massive water wheel in motion added a level of understanding to these investigations.

A quick break for lunch and we were off up to the quarry for our nature activities. To begin with we discussed the smells, textures, sounds and sights of the woodland. We then went on a mini-beast hunt which led to discussions on how to classify different species and the different habitats our mini-beasts favoured. After making our own ‘perfumes of the forest’, finding out how many legs a woodlice has and that boys are just as squeamish as girls – we moved on to our next activity and built a nest! The group were very enthusiastic, as you can tell from the pictures and the size of the branches/ trees they managed to move with their makeshift beaks (I think there may have been a little cheating here!). It was a fantastic photo opportunity and great fun.

Peredur met us at the Vivian Quarry and gave us an insight into it’s history, including a closer look at the cliffs of slate and an insight into how the Quarrymen worked and interpreted the face of the Quarry. He discussed the rock man’s terms used to differentiate sections of slate, the geology behind their make-up, and how being able to tell a ‘trwyn’ from a ‘cefn crwn‘ helped Quarrymen interpret the slate, manipulate it to the results they wanted, and lessen the risk to their lives through making it possible to predict the results of their work. This was fascinating, the Vivian Quarry provided a beautiful setting, and it was a lovely way to end our day.

I thoroughly enjoyed meeting year 6 St Brigid’s and being able to thank them personally for their contribution to the Spring Bulbs in Schools project. It was a fantastic day, and I would like to thank the staff at the National Slate Museum for their hospitality and the time and effort they gave to make the trip such fun.

Applications are now open for schools in Wales to participate in the Spring Bulbs Project 2015-16. The winners will receive an action packed class trip full of nature activities to their closest Amgueddfa Cymru – National Museum Wales site.

Apply here!

Applications are now closed for schools in England and Scotland, but these schools can find information on next years project (2016-17) on the Edina Trust website.

The first ever National Meadows Day is tomorrow, Saturday 4th July. You may have noticed National Museum Cardiff now has an Urban Meadow on the east side by the Reardon Smith Lecture Theatre. It gives us a fantastic new outdoor learning space where just a lawn used to be. Check out our programme of events based around the meadow in What's On.

Our Urban Meadow with the bee hives on the roof is a positive approach by the museum to increase pollinators within Cardiff and are funded entirely through landfill tax. Meadows on our other museum sites help pollinators throughout Wales. With a no dig, no chemical policy, as well as introducing plants and seeds from Flora Locale recommended suppliers, we are following sustainable principles. 

Children have used the Urban Meadow to start investigating the natural world, children who may not otherwise have visited a museum. The next event is ‘Family Fun in the Meadow’ on Saturday 11th July: Help our OPAL scientist to survey the bug life in our urban meadow and learn to be a botanical illustrator. See the What’s On guide for further information

You can find further information and links to events for National Meadow Day on the Plantlife webpages

Also you can follow the Twitter hashtag: #magnificentmeadowsday

By Sally Whyman and Kath Slade

Climate-change study in your own school yard
Science & Geography (KS2)

Make use of your outdoor classroom! Join the 175 schools taking part in this exciting investigation.

Spring Bulbs for Schools provides primary school pupils with the opportunity to adopt, study and record the development of spring bulbs as part of a spring watch network. Each pupil will receive a Tenby Daffodil, Crocus bulb and garden pot to record growth and flowering times.

Through collecting and comparing real data pupils discover how our changing climate is affecting our seasons and what this means for ourselves and the nature around us. Pupils take part in Professor Plant's Challenges to receive a super scientist certificate.

Any schools in Wales can take part as results are collected over the internet (or by post if necessary). This is an on-going investigation which means schools can take part year after year.

To apply for Spring Bulbs for Schools 2015-2016 please fill out the online application form by following the link below.

Application are now open but numbers are limited so apply soon to ensure your place on the project! Application is only open to schools in Wales. Recruitment for English and Scottish schools has closed but please contact The Edina Trust for information about taking part in the project 2016-2017.

Spring Bulbs for Schools - Application form

For enquiries please Email SCAN