Cyst-forming, Semi-Marine AmoeboFlagellates

The cyst-forming, semi-marine amoebo-flagellates (C-SMAFs)are a group of protist uniquely adapted to life in the demanding and hostile environment between land and sea.  Here amoebae must be able to stand the constantly changing conditions of salinity, temperature and moisture. The ability to encyst is obviously of paramount importance yet the importance of the ability to form flagella is less immediately clear and many of the amoebae found here do not have this ability (C-SMAs).  Prior to these studies, only one C-SMAF was known, Heteramoeba clara.  This was isolated in 1958 by Michael Droop (Droop, 1962) from   supra-littoral rock pools below a Gannet (Bas ) colony on the rocky island of Ailsa craig in the Firth of Clyde of the Scottish West coast.  This amoeba was fascinating since it was reported to have a sexual or para-sexual life style.  In order to study this interaction I have been attempting to isolate a fresh strain of Heteramoeba, but have discovered in the process that the supra-littoral rock-pool environment is home to a number of diverse Vahlkampfid amoeba and amoebo-flagelates.

Three main sites have been sampled as part of this study. 1). Mudflats at Aberlady bay, 2). Supra-littoral rock pool complex West of Gullane beach (see Fig1). 3). Supro-littoral rock pool complex at Western end of Yellowcraigs beach near Fidra Island.

I have studied a group of supralittoral rockpools on Gullane beach (East Lothian, Scotland) and isolated a number of amoebae through the year.  GB1, GB4 and GB2k

BB1, BM432, 

Dimorphamoeba

Where have C-SMAFs come from?

Amoebae from a suspected terrestrial environment have frequently been discovered in marine environments and have presumably been washed there by rivers or deposited there by human activity.  These amoebae are likely to be out-competed by better suited protists in time.  The C-SMAFs have features of both marine (seawater tolerance) and terrestrial (cyst formation) amoebae.  Part of my study aims to determine if the C-SMAFs represent a permanent population, or merely stray amoebae that just happen to end up in the rock pools from elsewhere and will shortly expire.  If the former is the case then I would expect to be able to isolate the same species repeatedly, but if the C-SMAFs are coming form elsewhere but can survive for a short time then I would expect to isolate many different species.  A possible source of the C-SMAFs is mudflats, here similar conditions of desiccation, and salinity changes are likely to occur and so it is possible that this is the actual permanent home of the C-SMAFs. So far I have succeeded in finding many different species but this may be due to my isolation technique.  Better methods are now being explored and I soon will be in a better position to answer the question.  A major difficult in this study is to identify various species of amoeba, morphology alone tells us that the amoebae in question belongs to the Vahlfampfiidae but molecular means are necessary to determine species.   I have using the approach of SSUrDNA gene sequencing (as have most others).

The importance of C-SMAFs to the shoreline economy.

Probably none since supra-littoral rock pools occupy such a small part of the shore!  However, it is possible that C-SMAFs are arriving at these rock-pools from the the higher reaches of mudflats.  Mudflats are important regions for biological productivity and if as has been shown in terrestrial soil that amoeba make a significant contribution to bacterial consumption then the C-SMAFs may be relevant.

Droop, M. R. (1962). "Heteramoeba clara n.gen, n.sp., a sexual biphasic amoeba." Archiv Für Mikrobiol. 42: 254-266.