The 27th November 2018 was a day like any other, with the first job on the to-do list; walk the dog. 

Living at Holy Vale my usual “go-to” dog walk is Holy Vale & Higher Moors Nature Trail, down to Porth Hellick and then I have the option of heading off around the Island either clockwise or widdershins depending on wind direction and my mood. 

Being an avid beachcomber however, we often we get “stuck” at Porth Hellick; especially when we’ve had “interesting” weather.  Today was one of those days.

As we walked across the gravel we came across what looked like hundreds of small plastic pouches dotted around between the high water mark and where the flats meet the slope of the beach; many of which appeared to be clumped together to form strings.  On closer inspection I could see that they were in fact some sort of living creature; many of which were moving, despite being stranded.

My initial thinking was that they might be some kind of Comb Jellyfish that I’d not seen before, but they didn’t seem quite right. 

Following taking some quick photos on my phone I turned to the trusty cyber beachcombing community on Twitter; tagging in my usual team of “Sea Monkeys”.

Within a couple of hours I didn’t have an ID but I did have a list of suggestions of what they could be (the most common and recurring being Salps); at this point I turned to Google as they were unlike Salps I had previously encountered.

During my searching I came across some images that looked very similar to the ones I had taken, luckily they came complete with their name!  After doing a quick Google search on the name I became even more convinced that this is what I’d found….Soestia zonaria.

I discovered that these deep-sea Salps come in both aggregated (chain) and solitary forms and that I had images of both types washed ashore on Porth Hellick.

On the 28th November 2018 I was contacted by a very excited Dr Paul Gainey who was bursting with questions about my find; following sending him an explanation of where and when I’d found them along with photographs and video he forwarded them on to Dr Keith Hiscock and Dr Dave Conway of the Marine Biological Association to try and gain some certainty on ID. 

Later that day I had confirmation in a lovely email from Paul.  Not only had Dave confirmed that my ID was correct he went on to say “A very distinctive species and a very interesting observation. They are recorded but are not very common in the area and to get a large number washed up is very unusual…Beautiful Images”.

Paul requested, if possible, that if I found any more I photographed them against a black background in order to show up the muscle bands more clearly; so armed with a jar I returned to Porth Hellick to see if I could find some more Salps. 

Sadly, most had vanished; however I did find a handful which I carefully carted home in a jar of seawater and proceeded to take photographs of in my adhoc studio setup in my kitchen.

A few weeks later I contacted Paul following a further find at Porth Hellick; these I recognised as Barrel Salps but to my surprise the majority contained “house guests”!  Again after a bit of a trawl through books and online I concluded that the “house guests” were likely Phronima sedentaria.

Paul once again enlisted the help of Dr David Conway and Dr Keith Hiscock in providing me not only with confirmation of my ID but also more information regarding the strange but fascinating creatures.

"Phronima  is a rather exotic and rare visitor to the British and Irish coastline. Phronima is a genus of small, often deep sea, hyperiid amphipods which have near-transparent bodies and which are found throughout the world’s oceans (except the polar regions), more especially in subtropical (e.g. The Mediterranean) and tropical regions. They are often referred to as being parasites although they would be more appropriately classified as parasitoids. Instead of constantly feeding on the host such as a salp, the female Phronima uses her mouth and claws to attack and hollow out the gelatinous tissue of the salp from inside to create a cavity into which she enters and lays her eggs.

The salp continues its journey through the water according to the currents and wind, but is also propelled forwards to some extent by ‘swimming’ actions of the female from either inside or outside of the salp and in the latter case looks just like a proud mother pushing her gelatinous, semi-transparent pram through the water.

During the propulsion fresh seawater passes through the anterior siphon/opening into the cavity over the eggs/larva, to be expelled via the posterior siphon/opening. In this way the eggs/larvae are constantly supplied with fresh seawater containing new supplies of food and oxygen and any waste products are removed. Dr David Conway (MBA) comments  on the Phronima parasitoid finds:-  “ I have sampled salp barrels with Phronima inside in the open ocean further south but to collect them on the shore in British waters is very unusual and special”." ~ Dr PA Gainey

My finds have been logged not only with the academics named herein but also with Cornwall Marine Strandings Network where S. zonaria was added as a new species in their database. 

Huge thanks to Dr Paul Gainey for his assistance in putting names to my discoveries.  If you come across anything resembling salps along our shores, please take photos if possible and report the find to [email protected] and the Cornwall Marine Strandings Network