Amgueddfa Blog: Natural Sciences

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

Following on from our last beekeeper's report, Ben tells us what has been happening:

11th June: “Returning from my travels it was exciting to go see the bees again. I must admit I was anxious, mainly because earlier in the week there had been reports on Wales Online of a swarm in the City Centre. The reported swarm had caused mayhem in the brewery quarter when a few thousand bees descended on a table outside the Yard public house.  When I’d heard about this swarm I feared the worst, were they our bees? Had we missed something? I’d heard reports from some of the museum technicians that there had been clouds of bees up near our hives on that Monday – perhaps that was them swarming!

I can’t describe my relief when I opened the hive of our strong colony to discover that it was full of bees. They were there, all present and correct! The weather was perfect, warm and still, ideal for thoroughly going through the hive! So, removing the heavy super full of honey, I delved straight into the brood box with the help of Sally and lots of smoke! I must admit though, hearing of Nigel’s six stings didn’t fill me with confidence! There are a lot of bees in this hive now and actually seeing what’s happening on the frame is really quite difficult! Going through each frame carefully revealed two Supersedence type queen cups and several play cells (unlaid cells where the bees practice making queen cells). These were removed and the hive was carefully put back together and some of the bees coaxed back inside! Interestingly, now the hive is very full, bees seem to accumulate at the entrance and around the lip of the brood box and they often need a bit of smoke to encourage them back inside.

On opening the weaker hive I was delighted to see that the bees have substantially increased in number and activity. The colony has increased in strength from the 1.5 frames of bees to 5 full frames of bees. Without wanting to disrupt the bees too much, I quickly went through the hive to check the brood pattern and food supplies. Seeing that there were adequate capped reserves of honey and that lots of the bees were returning covered in pollen I closed the hive up and strapped it back down.  Just as we were finishing up Sally was stung! I think the first time for the female bee keepers! Rather painfully she’d been stung right on her heal, somewhere I’d been stung previously so I can vouch for the fact that it really does hurt!

Perhaps our bees aren’t so choosy about who they sting after all!”

Every week on #FossilFriday we like to highlight specimens from the palaeontological collections of the Natural Sciences Department at Amgueddfa Cymru - National Museum Wales, via our @CardiffCurator Twitter account. Sometimes they are fossils on display at National Museum Cardiff, whilst at other times they form part of the collections behind the scenes.

Interested in trilobites, ammonites and dinosaurs? Then why not find out what we have been tweeting over the last year or so in the following two Storify Stories: ‘Friday is Fossil Time’ and ‘Fantastic Fossils’.

If you find these interesting why not follow us on Twitter.

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.