3: Artemia salina, a brine shrimp or ‘Sea-Monkey’
Artemia salina is a species of brine shrimp; an aquatic crustacean. They are not closely allied to true shrimp; indeed, they are more closely related to Triops. Brine shrimps are found worldwide in inland saline waters – they quickly perish in fresh water, but can survive in up to 50% salt solutions. Apparently they can also survive for several days swimming about in silver nitrate – which is impressive, but I wonder how useful that is?
Much like Triops, A. salina can produce eggs that can survive the drying out of a body of water, remain dormant for years, and hatch when water returns.
According to the Proceedings of the Zoological Society of London, A. salina was ‘first observed by M. Schlosser, in the salt-pans at Lymington’ (Baird, 1852). In 1879 Edward King, mayor of Lymington, wrote:
‘In this notice of our Salterns, we must not overlook a curious little creature that was found in them; and which has never been seen elsewhere, except in some salt-lakes of Siberia. It was known as The Lymington Brine Shrimp, and was first noticed by a Dr. Maty, about 1740. It lived in the brine tanks only, where no other creature could have existed, the concentrated salt-water being sufficient to destroy every marine organism. It was supposed, by the salt-makers, to cause a clearing of the brine; and was carefully transported to those vats which seemed to be deficient. It was never found in the evaporating pans, connected with the sea; but only in the deep store pits, which held the concentrated solution just before boiling.’ (King, 1879)
According to Wikipedia, Schlosser (presumably the same person as the ‘Dr Maty’ mentioned by King?) made drawings and a report of A. salina in 1756, which formed the basis of a description by Linnaeus in 1758 – he named it Cancer salina.
Since I first wrote the first draft of this article I have been given permission to reproduce one of Schlosser’s original drawings on the blog:
Schlosser’s drawing of A. salina, from ‘Historical Notes on Artemia salina (L.)’ by Kuenen & Becking, permission granted by the Naturalis Biodiverisity Center, Leiden, Holland. Major props to them for letting me use it. I also thoroughly recommend reading the paper it accompanies: http://www.repository.naturalis.nl/document/150623
Amusingly, as can be seen in Schlosser’s drawing above, A. salina has been drawn with the requisite 11 pairs of legs. Linnaeus, either by accident or design, described it as only having ten pairs. Why? Perhaps he assumed it should fit in with the decapoda order of crustaceans? This error persisted in the relevant literature for at least half a century – frustrating considering it was correct in the very first observation.
I have been unable to find out anything specific about the extinction of A. salina, so instead I’ll go for conjecture and hearsay. There is a website about the Lymington salt industry (http://www.lymington.org/history/thesaltindustry.html) and about halfway down there is section called ‘The decline of the Industry’. This section states that ‘The last salt house closed in 1865 and within a few years nearly everything had gone, the boiling houses were removed and the salt-ponds filled up and levelled off for grazing’. Presumably when the salt-ponds went, A. salina went with them. As Lymington was the only place A. salina was known from in the UK, this constituted British extinction. Poignant.
I think I drove through Lymington once whilst in Hampshire; I saw my first, and indeed only, Semipalmated Sandpiper and Sabine’s gull only a couple of miles away from where A. salina used to live.
Baird, W. (1852) Proceedings of the Zoological Society of London, Printed for the Society, sold at their house in Hanover Square.
King, E. (1879) Old times re-visited in the borough and parish of Lymington, Hants, Simpkins, London.